alistair23-linux/include/uapi/linux/perf_event.h

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/*
* Performance events:
*
* Copyright (C) 2008-2009, Thomas Gleixner <tglx@linutronix.de>
* Copyright (C) 2008-2011, Red Hat, Inc., Ingo Molnar
* Copyright (C) 2008-2011, Red Hat, Inc., Peter Zijlstra
*
* Data type definitions, declarations, prototypes.
*
* Started by: Thomas Gleixner and Ingo Molnar
*
* For licencing details see kernel-base/COPYING
*/
#ifndef _UAPI_LINUX_PERF_EVENT_H
#define _UAPI_LINUX_PERF_EVENT_H
#include <linux/types.h>
#include <linux/ioctl.h>
#include <asm/byteorder.h>
/*
* User-space ABI bits:
*/
/*
* attr.type
*/
enum perf_type_id {
PERF_TYPE_HARDWARE = 0,
PERF_TYPE_SOFTWARE = 1,
PERF_TYPE_TRACEPOINT = 2,
PERF_TYPE_HW_CACHE = 3,
PERF_TYPE_RAW = 4,
PERF_TYPE_BREAKPOINT = 5,
PERF_TYPE_MAX, /* non-ABI */
};
/*
* Generalized performance event event_id types, used by the
* attr.event_id parameter of the sys_perf_event_open()
* syscall:
*/
enum perf_hw_id {
/*
* Common hardware events, generalized by the kernel:
*/
PERF_COUNT_HW_CPU_CYCLES = 0,
PERF_COUNT_HW_INSTRUCTIONS = 1,
PERF_COUNT_HW_CACHE_REFERENCES = 2,
PERF_COUNT_HW_CACHE_MISSES = 3,
PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4,
PERF_COUNT_HW_BRANCH_MISSES = 5,
PERF_COUNT_HW_BUS_CYCLES = 6,
PERF_COUNT_HW_STALLED_CYCLES_FRONTEND = 7,
PERF_COUNT_HW_STALLED_CYCLES_BACKEND = 8,
PERF_COUNT_HW_REF_CPU_CYCLES = 9,
PERF_COUNT_HW_MAX, /* non-ABI */
};
/*
* Generalized hardware cache events:
*
* { L1-D, L1-I, LLC, ITLB, DTLB, BPU, NODE } x
* { read, write, prefetch } x
* { accesses, misses }
*/
enum perf_hw_cache_id {
PERF_COUNT_HW_CACHE_L1D = 0,
PERF_COUNT_HW_CACHE_L1I = 1,
PERF_COUNT_HW_CACHE_LL = 2,
PERF_COUNT_HW_CACHE_DTLB = 3,
PERF_COUNT_HW_CACHE_ITLB = 4,
PERF_COUNT_HW_CACHE_BPU = 5,
PERF_COUNT_HW_CACHE_NODE = 6,
PERF_COUNT_HW_CACHE_MAX, /* non-ABI */
};
enum perf_hw_cache_op_id {
PERF_COUNT_HW_CACHE_OP_READ = 0,
PERF_COUNT_HW_CACHE_OP_WRITE = 1,
PERF_COUNT_HW_CACHE_OP_PREFETCH = 2,
PERF_COUNT_HW_CACHE_OP_MAX, /* non-ABI */
};
enum perf_hw_cache_op_result_id {
PERF_COUNT_HW_CACHE_RESULT_ACCESS = 0,
PERF_COUNT_HW_CACHE_RESULT_MISS = 1,
PERF_COUNT_HW_CACHE_RESULT_MAX, /* non-ABI */
};
/*
* Special "software" events provided by the kernel, even if the hardware
* does not support performance events. These events measure various
* physical and sw events of the kernel (and allow the profiling of them as
* well):
*/
enum perf_sw_ids {
PERF_COUNT_SW_CPU_CLOCK = 0,
PERF_COUNT_SW_TASK_CLOCK = 1,
PERF_COUNT_SW_PAGE_FAULTS = 2,
PERF_COUNT_SW_CONTEXT_SWITCHES = 3,
PERF_COUNT_SW_CPU_MIGRATIONS = 4,
PERF_COUNT_SW_PAGE_FAULTS_MIN = 5,
PERF_COUNT_SW_PAGE_FAULTS_MAJ = 6,
PERF_COUNT_SW_ALIGNMENT_FAULTS = 7,
PERF_COUNT_SW_EMULATION_FAULTS = 8,
PERF_COUNT_SW_DUMMY = 9,
PERF_COUNT_SW_BPF_OUTPUT = 10,
PERF_COUNT_SW_MAX, /* non-ABI */
};
/*
* Bits that can be set in attr.sample_type to request information
* in the overflow packets.
*/
enum perf_event_sample_format {
PERF_SAMPLE_IP = 1U << 0,
PERF_SAMPLE_TID = 1U << 1,
PERF_SAMPLE_TIME = 1U << 2,
PERF_SAMPLE_ADDR = 1U << 3,
PERF_SAMPLE_READ = 1U << 4,
PERF_SAMPLE_CALLCHAIN = 1U << 5,
PERF_SAMPLE_ID = 1U << 6,
PERF_SAMPLE_CPU = 1U << 7,
PERF_SAMPLE_PERIOD = 1U << 8,
PERF_SAMPLE_STREAM_ID = 1U << 9,
PERF_SAMPLE_RAW = 1U << 10,
PERF_SAMPLE_BRANCH_STACK = 1U << 11,
PERF_SAMPLE_REGS_USER = 1U << 12,
PERF_SAMPLE_STACK_USER = 1U << 13,
PERF_SAMPLE_WEIGHT = 1U << 14,
PERF_SAMPLE_DATA_SRC = 1U << 15,
perf: make events stream always parsable The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-27 02:23:07 -06:00
PERF_SAMPLE_IDENTIFIER = 1U << 16,
perf: Add generic transaction flags Add a generic qualifier for transaction events, as a new sample type that returns a flag word. This is particularly useful for qualifying aborts: to distinguish aborts which happen due to asynchronous events (like conflicts caused by another CPU) versus instructions that lead to an abort. The tuning strategies are very different for those cases, so it's important to distinguish them easily and early. Since it's inconvenient and inflexible to filter for this in the kernel we report all the events out and allow some post processing in user space. The flags are based on the Intel TSX events, but should be fairly generic and mostly applicable to other HTM architectures too. In addition to various flag words there's also reserved space to report an program supplied abort code. For TSX this is used to distinguish specific classes of aborts, like a lock busy abort when doing lock elision. Flags: Elision and generic transactions (ELISION vs TRANSACTION) (HLE vs RTM on TSX; IBM etc. would likely only use TRANSACTION) Aborts caused by current thread vs aborts caused by others (SYNC vs ASYNC) Retryable transaction (RETRY) Conflicts with other threads (CONFLICT) Transaction write capacity overflow (CAPACITY WRITE) Transaction read capacity overflow (CAPACITY READ) Transactions implicitely aborted can also return an abort code. This can be used to signal specific events to the profiler. A common case is abort on lock busy in a RTM eliding library (code 0xff) To handle this case we include the TSX abort code Common example aborts in TSX would be: - Data conflict with another thread on memory read. Flags: TRANSACTION|ASYNC|CONFLICT - executing a WRMSR in a transaction. Flags: TRANSACTION|SYNC - HLE transaction in user space is too large Flags: ELISION|SYNC|CAPACITY-WRITE The only flag that is somewhat TSX specific is ELISION. This adds the perf core glue needed for reporting the new flag word out. v2: Add MEM/MISC v3: Move transaction to the end v4: Separate capacity-read/write and remove misc v5: Remove _SAMPLE. Move abort flags to 32bit. Rename transaction to txn Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379688044-14173-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20 08:40:39 -06:00
PERF_SAMPLE_TRANSACTION = 1U << 17,
PERF_SAMPLE_REGS_INTR = 1U << 18,
PERF_SAMPLE_MAX = 1U << 19, /* non-ABI */
};
/*
* values to program into branch_sample_type when PERF_SAMPLE_BRANCH is set
*
* If the user does not pass priv level information via branch_sample_type,
* the kernel uses the event's priv level. Branch and event priv levels do
* not have to match. Branch priv level is checked for permissions.
*
* The branch types can be combined, however BRANCH_ANY covers all types
* of branches and therefore it supersedes all the other types.
*/
enum perf_branch_sample_type_shift {
PERF_SAMPLE_BRANCH_USER_SHIFT = 0, /* user branches */
PERF_SAMPLE_BRANCH_KERNEL_SHIFT = 1, /* kernel branches */
PERF_SAMPLE_BRANCH_HV_SHIFT = 2, /* hypervisor branches */
PERF_SAMPLE_BRANCH_ANY_SHIFT = 3, /* any branch types */
PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT = 4, /* any call branch */
PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT = 5, /* any return branch */
PERF_SAMPLE_BRANCH_IND_CALL_SHIFT = 6, /* indirect calls */
PERF_SAMPLE_BRANCH_ABORT_TX_SHIFT = 7, /* transaction aborts */
PERF_SAMPLE_BRANCH_IN_TX_SHIFT = 8, /* in transaction */
PERF_SAMPLE_BRANCH_NO_TX_SHIFT = 9, /* not in transaction */
PERF_SAMPLE_BRANCH_COND_SHIFT = 10, /* conditional branches */
PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT = 11, /* call/ret stack */
PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT = 12, /* indirect jumps */
PERF_SAMPLE_BRANCH_CALL_SHIFT = 13, /* direct call */
perf/x86: Add option to disable reading branch flags/cycles With LBRv5 reading the extra LBR flags like mispredict, TSX, cycles is not free anymore, as it has moved to a separate MSR. For callstack mode we don't need any of this information; so we can avoid the unnecessary MSR read. Add flags to the perf interface where perf record can request not collecting this information. Add branch_sample_type flags for CYCLES and FLAGS. It's a bit unusual for branch_sample_types to be negative (disable), not positive (enable), but since the legacy ABI reported the flags we need some form of explicit disabling to avoid breaking the ABI. After we have the flags the x86 perf code can keep track if any users need the flags. If noone needs it the information is not collected. This cuts down the cost of LBR callstack on Skylake significantly. Profiling a kernel build with LBR call stack the average run time of the PMI handler drops by 43%. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1445366797-30894-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 12:46:34 -06:00
PERF_SAMPLE_BRANCH_NO_FLAGS_SHIFT = 14, /* no flags */
PERF_SAMPLE_BRANCH_NO_CYCLES_SHIFT = 15, /* no cycles */
PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */
};
enum perf_branch_sample_type {
PERF_SAMPLE_BRANCH_USER = 1U << PERF_SAMPLE_BRANCH_USER_SHIFT,
PERF_SAMPLE_BRANCH_KERNEL = 1U << PERF_SAMPLE_BRANCH_KERNEL_SHIFT,
PERF_SAMPLE_BRANCH_HV = 1U << PERF_SAMPLE_BRANCH_HV_SHIFT,
PERF_SAMPLE_BRANCH_ANY = 1U << PERF_SAMPLE_BRANCH_ANY_SHIFT,
PERF_SAMPLE_BRANCH_ANY_CALL = 1U << PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT,
PERF_SAMPLE_BRANCH_ANY_RETURN = 1U << PERF_SAMPLE_BRANCH_ANY_RETURN_SHIFT,
PERF_SAMPLE_BRANCH_IND_CALL = 1U << PERF_SAMPLE_BRANCH_IND_CALL_SHIFT,
PERF_SAMPLE_BRANCH_ABORT_TX = 1U << PERF_SAMPLE_BRANCH_ABORT_TX_SHIFT,
PERF_SAMPLE_BRANCH_IN_TX = 1U << PERF_SAMPLE_BRANCH_IN_TX_SHIFT,
PERF_SAMPLE_BRANCH_NO_TX = 1U << PERF_SAMPLE_BRANCH_NO_TX_SHIFT,
PERF_SAMPLE_BRANCH_COND = 1U << PERF_SAMPLE_BRANCH_COND_SHIFT,
PERF_SAMPLE_BRANCH_CALL_STACK = 1U << PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT,
PERF_SAMPLE_BRANCH_IND_JUMP = 1U << PERF_SAMPLE_BRANCH_IND_JUMP_SHIFT,
PERF_SAMPLE_BRANCH_CALL = 1U << PERF_SAMPLE_BRANCH_CALL_SHIFT,
perf/x86: Add option to disable reading branch flags/cycles With LBRv5 reading the extra LBR flags like mispredict, TSX, cycles is not free anymore, as it has moved to a separate MSR. For callstack mode we don't need any of this information; so we can avoid the unnecessary MSR read. Add flags to the perf interface where perf record can request not collecting this information. Add branch_sample_type flags for CYCLES and FLAGS. It's a bit unusual for branch_sample_types to be negative (disable), not positive (enable), but since the legacy ABI reported the flags we need some form of explicit disabling to avoid breaking the ABI. After we have the flags the x86 perf code can keep track if any users need the flags. If noone needs it the information is not collected. This cuts down the cost of LBR callstack on Skylake significantly. Profiling a kernel build with LBR call stack the average run time of the PMI handler drops by 43%. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1445366797-30894-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-20 12:46:34 -06:00
PERF_SAMPLE_BRANCH_NO_FLAGS = 1U << PERF_SAMPLE_BRANCH_NO_FLAGS_SHIFT,
PERF_SAMPLE_BRANCH_NO_CYCLES = 1U << PERF_SAMPLE_BRANCH_NO_CYCLES_SHIFT,
PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
};
#define PERF_SAMPLE_BRANCH_PLM_ALL \
(PERF_SAMPLE_BRANCH_USER|\
PERF_SAMPLE_BRANCH_KERNEL|\
PERF_SAMPLE_BRANCH_HV)
/*
* Values to determine ABI of the registers dump.
*/
enum perf_sample_regs_abi {
PERF_SAMPLE_REGS_ABI_NONE = 0,
PERF_SAMPLE_REGS_ABI_32 = 1,
PERF_SAMPLE_REGS_ABI_64 = 2,
};
perf: Add generic transaction flags Add a generic qualifier for transaction events, as a new sample type that returns a flag word. This is particularly useful for qualifying aborts: to distinguish aborts which happen due to asynchronous events (like conflicts caused by another CPU) versus instructions that lead to an abort. The tuning strategies are very different for those cases, so it's important to distinguish them easily and early. Since it's inconvenient and inflexible to filter for this in the kernel we report all the events out and allow some post processing in user space. The flags are based on the Intel TSX events, but should be fairly generic and mostly applicable to other HTM architectures too. In addition to various flag words there's also reserved space to report an program supplied abort code. For TSX this is used to distinguish specific classes of aborts, like a lock busy abort when doing lock elision. Flags: Elision and generic transactions (ELISION vs TRANSACTION) (HLE vs RTM on TSX; IBM etc. would likely only use TRANSACTION) Aborts caused by current thread vs aborts caused by others (SYNC vs ASYNC) Retryable transaction (RETRY) Conflicts with other threads (CONFLICT) Transaction write capacity overflow (CAPACITY WRITE) Transaction read capacity overflow (CAPACITY READ) Transactions implicitely aborted can also return an abort code. This can be used to signal specific events to the profiler. A common case is abort on lock busy in a RTM eliding library (code 0xff) To handle this case we include the TSX abort code Common example aborts in TSX would be: - Data conflict with another thread on memory read. Flags: TRANSACTION|ASYNC|CONFLICT - executing a WRMSR in a transaction. Flags: TRANSACTION|SYNC - HLE transaction in user space is too large Flags: ELISION|SYNC|CAPACITY-WRITE The only flag that is somewhat TSX specific is ELISION. This adds the perf core glue needed for reporting the new flag word out. v2: Add MEM/MISC v3: Move transaction to the end v4: Separate capacity-read/write and remove misc v5: Remove _SAMPLE. Move abort flags to 32bit. Rename transaction to txn Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1379688044-14173-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-20 08:40:39 -06:00
/*
* Values for the memory transaction event qualifier, mostly for
* abort events. Multiple bits can be set.
*/
enum {
PERF_TXN_ELISION = (1 << 0), /* From elision */
PERF_TXN_TRANSACTION = (1 << 1), /* From transaction */
PERF_TXN_SYNC = (1 << 2), /* Instruction is related */
PERF_TXN_ASYNC = (1 << 3), /* Instruction not related */
PERF_TXN_RETRY = (1 << 4), /* Retry possible */
PERF_TXN_CONFLICT = (1 << 5), /* Conflict abort */
PERF_TXN_CAPACITY_WRITE = (1 << 6), /* Capacity write abort */
PERF_TXN_CAPACITY_READ = (1 << 7), /* Capacity read abort */
PERF_TXN_MAX = (1 << 8), /* non-ABI */
/* bits 32..63 are reserved for the abort code */
PERF_TXN_ABORT_MASK = (0xffffffffULL << 32),
PERF_TXN_ABORT_SHIFT = 32,
};
/*
* The format of the data returned by read() on a perf event fd,
* as specified by attr.read_format:
*
* struct read_format {
* { u64 value;
* { u64 time_enabled; } && PERF_FORMAT_TOTAL_TIME_ENABLED
* { u64 time_running; } && PERF_FORMAT_TOTAL_TIME_RUNNING
* { u64 id; } && PERF_FORMAT_ID
* } && !PERF_FORMAT_GROUP
*
* { u64 nr;
* { u64 time_enabled; } && PERF_FORMAT_TOTAL_TIME_ENABLED
* { u64 time_running; } && PERF_FORMAT_TOTAL_TIME_RUNNING
* { u64 value;
* { u64 id; } && PERF_FORMAT_ID
* } cntr[nr];
* } && PERF_FORMAT_GROUP
* };
*/
enum perf_event_read_format {
PERF_FORMAT_TOTAL_TIME_ENABLED = 1U << 0,
PERF_FORMAT_TOTAL_TIME_RUNNING = 1U << 1,
PERF_FORMAT_ID = 1U << 2,
PERF_FORMAT_GROUP = 1U << 3,
PERF_FORMAT_MAX = 1U << 4, /* non-ABI */
};
#define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */
#define PERF_ATTR_SIZE_VER1 72 /* add: config2 */
#define PERF_ATTR_SIZE_VER2 80 /* add: branch_sample_type */
#define PERF_ATTR_SIZE_VER3 96 /* add: sample_regs_user */
/* add: sample_stack_user */
#define PERF_ATTR_SIZE_VER4 104 /* add: sample_regs_intr */
#define PERF_ATTR_SIZE_VER5 112 /* add: aux_watermark */
/*
* Hardware event_id to monitor via a performance monitoring event:
*
* @sample_max_stack: Max number of frame pointers in a callchain,
* should be < /proc/sys/kernel/perf_event_max_stack
*/
struct perf_event_attr {
/*
* Major type: hardware/software/tracepoint/etc.
*/
__u32 type;
/*
* Size of the attr structure, for fwd/bwd compat.
*/
__u32 size;
/*
* Type specific configuration information.
*/
__u64 config;
union {
__u64 sample_period;
__u64 sample_freq;
};
__u64 sample_type;
__u64 read_format;
__u64 disabled : 1, /* off by default */
inherit : 1, /* children inherit it */
pinned : 1, /* must always be on PMU */
exclusive : 1, /* only group on PMU */
exclude_user : 1, /* don't count user */
exclude_kernel : 1, /* ditto kernel */
exclude_hv : 1, /* ditto hypervisor */
exclude_idle : 1, /* don't count when idle */
mmap : 1, /* include mmap data */
comm : 1, /* include comm data */
freq : 1, /* use freq, not period */
inherit_stat : 1, /* per task counts */
enable_on_exec : 1, /* next exec enables */
task : 1, /* trace fork/exit */
watermark : 1, /* wakeup_watermark */
/*
* precise_ip:
*
* 0 - SAMPLE_IP can have arbitrary skid
* 1 - SAMPLE_IP must have constant skid
* 2 - SAMPLE_IP requested to have 0 skid
* 3 - SAMPLE_IP must have 0 skid
*
* See also PERF_RECORD_MISC_EXACT_IP
*/
precise_ip : 2, /* skid constraint */
mmap_data : 1, /* non-exec mmap data */
sample_id_all : 1, /* sample_type all events */
exclude_host : 1, /* don't count in host */
exclude_guest : 1, /* don't count in guest */
exclude_callchain_kernel : 1, /* exclude kernel callchains */
exclude_callchain_user : 1, /* exclude user callchains */
mmap2 : 1, /* include mmap with inode data */
comm_exec : 1, /* flag comm events that are due to an exec */
perf: Add per event clockid support While thinking on the whole clock discussion it occurred to me we have two distinct uses of time: 1) the tracking of event/ctx/cgroup enabled/running/stopped times which includes the self-monitoring support in struct perf_event_mmap_page. 2) the actual timestamps visible in the data records. And we've been conflating them. The first is all about tracking time deltas, nobody should really care in what time base that happens, its all relative information, as long as its internally consistent it works. The second however is what people are worried about when having to merge their data with external sources. And here we have the discussion on MONOTONIC vs MONOTONIC_RAW etc.. Where MONOTONIC is good for correlating between machines (static offset), MONOTNIC_RAW is required for correlating against a fixed rate hardware clock. This means configurability; now 1) makes that hard because it needs to be internally consistent across groups of unrelated events; which is why we had to have a global perf_clock(). However, for 2) it doesn't really matter, perf itself doesn't care what it writes into the buffer. The below patch makes the distinction between these two cases by adding perf_event_clock() which is used for the second case. It further makes this configurable on a per-event basis, but adds a few sanity checks such that we cannot combine events with different clocks in confusing ways. And since we then have per-event configurability we might as well retain the 'legacy' behaviour as a default. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-20 06:05:38 -07:00
use_clockid : 1, /* use @clockid for time fields */
perf: Add PERF_RECORD_SWITCH to indicate context switches There are already two events for context switches, namely the tracepoint sched:sched_switch and the software event context_switches. Unfortunately neither are suitable for use by non-privileged users for the purpose of synchronizing hardware trace data (e.g. Intel PT) to the context switch. Tracepoints are no good at all for non-privileged users because they need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= -1. On the other hand, kernel software events need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= 1. Now many distributions do default perf_event_paranoid to 1 making context_switches a contender, except it has another problem (which is also shared with sched:sched_switch) which is that it happens before perf schedules events out instead of after perf schedules events in. Whereas a privileged user can see all the events anyway, a non-privileged user only sees events for their own processes, in other words they see when their process was scheduled out not when it was scheduled in. That presents two problems to use the event: 1. the information comes too late, so tools have to look ahead in the event stream to find out what the current state is 2. if they are unlucky tracing might have stopped before the context-switches event is recorded. This new PERF_RECORD_SWITCH event does not have those problems and it also has a couple of other small advantages. It is easier to use because it is an auxiliary event (like mmap, comm and task events) which can be enabled by setting a single bit. It is smaller than sched:sched_switch and easier to parse. To make the event useful for privileged users also, if the context is cpu-wide then the event record will be PERF_RECORD_SWITCH_CPU_WIDE which is the same as PERF_RECORD_SWITCH except it also provides the next or previous pid/tid. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1437471846-26995-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-21 03:44:02 -06:00
context_switch : 1, /* context switch data */
perf/core: Add ::write_backward attribute to perf event This patch introduces 'write_backward' bit to perf_event_attr, which controls the direction of a ring buffer. After set, the corresponding ring buffer is written from end to beginning. This feature is design to support reading from overwritable ring buffer. Ring buffer can be created by mapping a perf event fd. Kernel puts event records into ring buffer, user tooling like perf fetch them from address returned by mmap(). To prevent racing between kernel and tooling, they communicate to each other through 'head' and 'tail' pointers. Kernel maintains 'head' pointer, points it to the next free area (tail of the last record). Tooling maintains 'tail' pointer, points it to the tail of last consumed record (record has already been fetched). Kernel determines the available space in a ring buffer using these two pointers to avoid overwrite unfetched records. By mapping without 'PROT_WRITE', an overwritable ring buffer is created. Different from normal ring buffer, tooling is unable to maintain 'tail' pointer because writing is forbidden. Therefore, for this type of ring buffers, kernel overwrite old records unconditionally, works like flight recorder. This feature would be useful if reading from overwritable ring buffer were as easy as reading from normal ring buffer. However, there's an obscure problem. The following figure demonstrates a full overwritable ring buffer. In this figure, the 'head' pointer points to the end of last record, and a long record 'E' is pending. For a normal ring buffer, a 'tail' pointer would have pointed to position (X), so kernel knows there's no more space in the ring buffer. However, for an overwritable ring buffer, kernel ignore the 'tail' pointer. (X) head . | . V +------+-------+----------+------+---+ |A....A|B.....B|C........C|D....D| | +------+-------+----------+------+---+ Record 'A' is overwritten by event 'E': head | V +--+---+-------+----------+------+---+ |.E|..A|B.....B|C........C|D....D|E..| +--+---+-------+----------+------+---+ Now tooling decides to read from this ring buffer. However, none of these two natural positions, 'head' and the start of this ring buffer, are pointing to the head of a record. Even the full ring buffer can be accessed by tooling, it is unable to find a position to start decoding. The first attempt tries to solve this problem AFAIK can be found from [1]. It makes kernel to maintain 'tail' pointer: updates it when ring buffer is half full. However, this approach introduces overhead to fast path. Test result shows a 1% overhead [2]. In addition, this method utilizes no more tham 50% records. Another attempt can be found from [3], which allows putting the size of an event at the end of each record. This approach allows tooling to find records in a backward manner from 'head' pointer by reading size of a record from its tail. However, because of alignment requirement, it needs 8 bytes to record the size of a record, which is a huge waste. Its performance is also not good, because more data need to be written. This approach also introduces some extra branch instructions to fast path. 'write_backward' is a better solution to this problem. Following figure demonstrates the state of the overwritable ring buffer when 'write_backward' is set before overwriting: head | V +---+------+----------+-------+------+ | |D....D|C........C|B.....B|A....A| +---+------+----------+-------+------+ and after overwriting: head | V +---+------+----------+-------+---+--+ |..E|D....D|C........C|B.....B|A..|E.| +---+------+----------+-------+---+--+ In each situation, 'head' points to the beginning of the newest record. From this record, tooling can iterate over the full ring buffer and fetch records one by one. The only limitation that needs to be considered is back-to-back reading. Due to the non-deterministic of user programs, it is impossible to ensure the ring buffer keeps stable during reading. Consider an extreme situation: tooling is scheduled out after reading record 'D', then a burst of events come, eat up the whole ring buffer (one or multiple rounds). When the tooling process comes back, reading after 'D' is incorrect now. To prevent this problem, we need to find a way to ensure the ring buffer is stable during reading. ioctl(PERF_EVENT_IOC_PAUSE_OUTPUT) is suggested because its overhead is lower than ioctl(PERF_EVENT_IOC_ENABLE). By carefully verifying 'header' pointer, reader can avoid pausing the ring-buffer. For example: /* A union of all possible events */ union perf_event event; p = head = perf_mmap__read_head(); while (true) { /* copy header of next event */ fetch(&event.header, p, sizeof(event.header)); /* read 'head' pointer */ head = perf_mmap__read_head(); /* check overwritten: is the header good? */ if (!verify(sizeof(event.header), p, head)) break; /* copy the whole event */ fetch(&event, p, event.header.size); /* read 'head' pointer again */ head = perf_mmap__read_head(); /* is the whole event good? */ if (!verify(event.header.size, p, head)) break; p += event.header.size; } However, the overhead is high because: a) In-place decoding is not safe. Copying-verifying-decoding is required. b) Fetching 'head' pointer requires additional synchronization. (From Alexei Starovoitov: Even when this trick works, pause is needed for more than stability of reading. When we collect the events into overwrite buffer we're waiting for some other trigger (like all cpu utilization spike or just one cpu running and all others are idle) and when it happens the buffer has valuable info from the past. At this point new events are no longer interesting and buffer should be paused, events read and unpaused until next trigger comes.) This patch utilizes event's default overflow_handler introduced previously. perf_event_output_backward() is created as the default overflow handler for backward ring buffers. To avoid extra overhead to fast path, original perf_event_output() becomes __perf_event_output() and marked '__always_inline'. In theory, there's no extra overhead introduced to fast path. Performance testing: Calling 3000000 times of 'close(-1)', use gettimeofday() to check duration. Use 'perf record -o /dev/null -e raw_syscalls:*' to capture system calls. In ns. Testing environment: CPU : Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz Kernel : v4.5.0 MEAN STDVAR BASE 800214.950 2853.083 PRE1 2253846.700 9997.014 PRE2 2257495.540 8516.293 POST 2250896.100 8933.921 Where 'BASE' is pure performance without capturing. 'PRE1' is test result of pure 'v4.5.0' kernel. 'PRE2' is test result before this patch. 'POST' is test result after this patch. See [4] for the detailed experimental setup. Considering the stdvar, this patch doesn't introduce performance overhead to the fast path. [1] http://lkml.iu.edu/hypermail/linux/kernel/1304.1/04584.html [2] http://lkml.iu.edu/hypermail/linux/kernel/1307.1/00535.html [3] http://lkml.iu.edu/hypermail/linux/kernel/1512.0/01265.html [4] http://lkml.kernel.org/g/56F89DCD.1040202@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: <acme@kernel.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459865478-53413-1-git-send-email-wangnan0@huawei.com [ Fixed the changelog some more. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-05 08:11:18 -06:00
write_backward : 1, /* Write ring buffer from end to beginning */
__reserved_1 : 36;
union {
__u32 wakeup_events; /* wakeup every n events */
__u32 wakeup_watermark; /* bytes before wakeup */
};
__u32 bp_type;
union {
__u64 bp_addr;
__u64 config1; /* extension of config */
};
union {
__u64 bp_len;
__u64 config2; /* extension of config1 */
};
__u64 branch_sample_type; /* enum perf_branch_sample_type */
/*
* Defines set of user regs to dump on samples.
* See asm/perf_regs.h for details.
*/
__u64 sample_regs_user;
/*
* Defines size of the user stack to dump on samples.
*/
__u32 sample_stack_user;
perf: Add per event clockid support While thinking on the whole clock discussion it occurred to me we have two distinct uses of time: 1) the tracking of event/ctx/cgroup enabled/running/stopped times which includes the self-monitoring support in struct perf_event_mmap_page. 2) the actual timestamps visible in the data records. And we've been conflating them. The first is all about tracking time deltas, nobody should really care in what time base that happens, its all relative information, as long as its internally consistent it works. The second however is what people are worried about when having to merge their data with external sources. And here we have the discussion on MONOTONIC vs MONOTONIC_RAW etc.. Where MONOTONIC is good for correlating between machines (static offset), MONOTNIC_RAW is required for correlating against a fixed rate hardware clock. This means configurability; now 1) makes that hard because it needs to be internally consistent across groups of unrelated events; which is why we had to have a global perf_clock(). However, for 2) it doesn't really matter, perf itself doesn't care what it writes into the buffer. The below patch makes the distinction between these two cases by adding perf_event_clock() which is used for the second case. It further makes this configurable on a per-event basis, but adds a few sanity checks such that we cannot combine events with different clocks in confusing ways. And since we then have per-event configurability we might as well retain the 'legacy' behaviour as a default. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-20 06:05:38 -07:00
__s32 clockid;
/*
* Defines set of regs to dump for each sample
* state captured on:
* - precise = 0: PMU interrupt
* - precise > 0: sampled instruction
*
* See asm/perf_regs.h for details.
*/
__u64 sample_regs_intr;
/*
* Wakeup watermark for AUX area
*/
__u32 aux_watermark;
__u16 sample_max_stack;
__u16 __reserved_2; /* align to __u64 */
};
#define perf_flags(attr) (*(&(attr)->read_format + 1))
/*
* Ioctls that can be done on a perf event fd:
*/
#define PERF_EVENT_IOC_ENABLE _IO ('$', 0)
#define PERF_EVENT_IOC_DISABLE _IO ('$', 1)
#define PERF_EVENT_IOC_REFRESH _IO ('$', 2)
#define PERF_EVENT_IOC_RESET _IO ('$', 3)
#define PERF_EVENT_IOC_PERIOD _IOW('$', 4, __u64)
#define PERF_EVENT_IOC_SET_OUTPUT _IO ('$', 5)
#define PERF_EVENT_IOC_SET_FILTER _IOW('$', 6, char *)
#define PERF_EVENT_IOC_ID _IOR('$', 7, __u64 *)
tracing, perf: Implement BPF programs attached to kprobes BPF programs, attached to kprobes, provide a safe way to execute user-defined BPF byte-code programs without being able to crash or hang the kernel in any way. The BPF engine makes sure that such programs have a finite execution time and that they cannot break out of their sandbox. The user interface is to attach to a kprobe via the perf syscall: struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .config = event_id, ... }; event_fd = perf_event_open(&attr,...); ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); 'prog_fd' is a file descriptor associated with BPF program previously loaded. 'event_id' is an ID of the kprobe created. Closing 'event_fd': close(event_fd); ... automatically detaches BPF program from it. BPF programs can call in-kernel helper functions to: - lookup/update/delete elements in maps - probe_read - wraper of probe_kernel_read() used to access any kernel data structures BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is architecture dependent) and return 0 to ignore the event and 1 to store kprobe event into the ring buffer. Note, kprobes are a fundamentally _not_ a stable kernel ABI, so BPF programs attached to kprobes must be recompiled for every kernel version and user must supply correct LINUX_VERSION_CODE in attr.kern_version during bpf_prog_load() call. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-25 13:49:20 -06:00
#define PERF_EVENT_IOC_SET_BPF _IOW('$', 8, __u32)
perf/ring_buffer: Introduce new ioctl options to pause and resume the ring-buffer Add new ioctl() to pause/resume ring-buffer output. In some situations we want to read from the ring-buffer only when we ensure nothing can write to the ring-buffer during reading. Without this patch we have to turn off all events attached to this ring-buffer to achieve this. This patch is a prerequisite to enable overwrite support for the perf ring-buffer support. Following commits will introduce new methods support reading from overwrite ring buffer. Before reading, caller must ensure the ring buffer is frozen, or the reading is unreliable. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459147292-239310-2-git-send-email-wangnan0@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-28 00:41:29 -06:00
#define PERF_EVENT_IOC_PAUSE_OUTPUT _IOW('$', 9, __u32)
enum perf_event_ioc_flags {
PERF_IOC_FLAG_GROUP = 1U << 0,
};
/*
* Structure of the page that can be mapped via mmap
*/
struct perf_event_mmap_page {
__u32 version; /* version number of this structure */
__u32 compat_version; /* lowest version this is compat with */
/*
* Bits needed to read the hw events in user-space.
*
* u32 seq, time_mult, time_shift, index, width;
* u64 count, enabled, running;
* u64 cyc, time_offset;
* s64 pmc = 0;
*
* do {
* seq = pc->lock;
* barrier()
*
* enabled = pc->time_enabled;
* running = pc->time_running;
*
* if (pc->cap_usr_time && enabled != running) {
* cyc = rdtsc();
* time_offset = pc->time_offset;
* time_mult = pc->time_mult;
* time_shift = pc->time_shift;
* }
*
* index = pc->index;
* count = pc->offset;
* if (pc->cap_user_rdpmc && index) {
* width = pc->pmc_width;
* pmc = rdpmc(index - 1);
* }
*
* barrier();
* } while (pc->lock != seq);
*
* NOTE: for obvious reason this only works on self-monitoring
* processes.
*/
__u32 lock; /* seqlock for synchronization */
__u32 index; /* hardware event identifier */
__s64 offset; /* add to hardware event value */
__u64 time_enabled; /* time event active */
__u64 time_running; /* time event on cpu */
union {
__u64 capabilities;
struct {
perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page' Solve the problems around the broken definition of perf_event_mmap_page:: cap_usr_time and cap_usr_rdpmc fields which used to overlap, partially fixed by: 860f085b74e9 ("perf: Fix broken union in 'struct perf_event_mmap_page'") The problem with the fix (merged in v3.12-rc1 and not yet released officially), noticed by Vince Weaver is that the new behavior is not detectable by new user-space, and that due to the reuse of the field names it's easy to mis-compile a binary if old headers are used on a new kernel or new headers are used on an old kernel. To solve all that make this change explicit, detectable and self-contained, by iterating the ABI the following way: - Always clear bit 0, and rename it to usrpage->cap_bit0, to at least not confuse old user-space binaries. RDPMC will be marked as unavailable to old binaries but that's within the ABI, this is a capability bit. - Rename bit 1 to ->cap_bit0_is_deprecated and always set it to 1, so new libraries can reliably detect that bit 0 is deprecated and perma-zero without having to check the kernel version. - Use bits 2, 3, 4 for the newly defined, correct functionality: cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */ cap_user_time : 1, /* The time_* fields are used */ cap_user_time_zero : 1, /* The time_zero field is used */ - Rename all the bitfield names in perf_event.h to be different from the old names, to make sure it's not possible to mis-compile it accidentally with old assumptions. The 'size' field can then be used in the future to add new fields and it will act as a natural ABI version indicator as well. Also adjust tools/perf/ userspace for the new definitions, noticed by Adrian Hunter. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Also-Fixed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/n/tip-zr03yxjrpXesOzzupszqglbv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-19 02:16:42 -06:00
__u64 cap_bit0 : 1, /* Always 0, deprecated, see commit 860f085b74e9 */
cap_bit0_is_deprecated : 1, /* Always 1, signals that bit 0 is zero */
cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */
cap_user_time : 1, /* The time_* fields are used */
cap_user_time_zero : 1, /* The time_zero field is used */
cap_____res : 59;
};
};
/*
* If cap_user_rdpmc this field provides the bit-width of the value
* read using the rdpmc() or equivalent instruction. This can be used
* to sign extend the result like:
*
* pmc <<= 64 - width;
* pmc >>= 64 - width; // signed shift right
* count += pmc;
*/
__u16 pmc_width;
/*
* If cap_usr_time the below fields can be used to compute the time
* delta since time_enabled (in ns) using rdtsc or similar.
*
* u64 quot, rem;
* u64 delta;
*
* quot = (cyc >> time_shift);
perf/x86: Fix time_shift in perf_event_mmap_page Commit: b20112edeadf ("perf/x86: Improve accuracy of perf/sched clock") allowed the time_shift value in perf_event_mmap_page to be as much as 32. Unfortunately the documented algorithms for using time_shift have it shifting an integer, whereas to work correctly with the value 32, the type must be u64. In the case of perf tools, Intel PT decodes correctly but the timestamps that are output (for example by perf script) have lost 32-bits of granularity so they look like they are not changing at all. Fix by limiting the shift to 31 and adjusting the multiplier accordingly. Also update the documentation of perf_event_mmap_page so that new code based on it will be more future-proof. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: b20112edeadf ("perf/x86: Improve accuracy of perf/sched clock") Link: http://lkml.kernel.org/r/1445001845-13688-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-16 07:24:05 -06:00
* rem = cyc & (((u64)1 << time_shift) - 1);
* delta = time_offset + quot * time_mult +
* ((rem * time_mult) >> time_shift);
*
* Where time_offset,time_mult,time_shift and cyc are read in the
* seqcount loop described above. This delta can then be added to
* enabled and possible running (if index), improving the scaling:
*
* enabled += delta;
* if (index)
* running += delta;
*
* quot = count / running;
* rem = count % running;
* count = quot * enabled + (rem * enabled) / running;
*/
__u16 time_shift;
__u32 time_mult;
__u64 time_offset;
/*
* If cap_usr_time_zero, the hardware clock (e.g. TSC) can be calculated
* from sample timestamps.
*
* time = timestamp - time_zero;
* quot = time / time_mult;
* rem = time % time_mult;
* cyc = (quot << time_shift) + (rem << time_shift) / time_mult;
*
* And vice versa:
*
* quot = cyc >> time_shift;
perf/x86: Fix time_shift in perf_event_mmap_page Commit: b20112edeadf ("perf/x86: Improve accuracy of perf/sched clock") allowed the time_shift value in perf_event_mmap_page to be as much as 32. Unfortunately the documented algorithms for using time_shift have it shifting an integer, whereas to work correctly with the value 32, the type must be u64. In the case of perf tools, Intel PT decodes correctly but the timestamps that are output (for example by perf script) have lost 32-bits of granularity so they look like they are not changing at all. Fix by limiting the shift to 31 and adjusting the multiplier accordingly. Also update the documentation of perf_event_mmap_page so that new code based on it will be more future-proof. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: b20112edeadf ("perf/x86: Improve accuracy of perf/sched clock") Link: http://lkml.kernel.org/r/1445001845-13688-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-16 07:24:05 -06:00
* rem = cyc & (((u64)1 << time_shift) - 1);
* timestamp = time_zero + quot * time_mult +
* ((rem * time_mult) >> time_shift);
*/
__u64 time_zero;
perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page' Solve the problems around the broken definition of perf_event_mmap_page:: cap_usr_time and cap_usr_rdpmc fields which used to overlap, partially fixed by: 860f085b74e9 ("perf: Fix broken union in 'struct perf_event_mmap_page'") The problem with the fix (merged in v3.12-rc1 and not yet released officially), noticed by Vince Weaver is that the new behavior is not detectable by new user-space, and that due to the reuse of the field names it's easy to mis-compile a binary if old headers are used on a new kernel or new headers are used on an old kernel. To solve all that make this change explicit, detectable and self-contained, by iterating the ABI the following way: - Always clear bit 0, and rename it to usrpage->cap_bit0, to at least not confuse old user-space binaries. RDPMC will be marked as unavailable to old binaries but that's within the ABI, this is a capability bit. - Rename bit 1 to ->cap_bit0_is_deprecated and always set it to 1, so new libraries can reliably detect that bit 0 is deprecated and perma-zero without having to check the kernel version. - Use bits 2, 3, 4 for the newly defined, correct functionality: cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */ cap_user_time : 1, /* The time_* fields are used */ cap_user_time_zero : 1, /* The time_zero field is used */ - Rename all the bitfield names in perf_event.h to be different from the old names, to make sure it's not possible to mis-compile it accidentally with old assumptions. The 'size' field can then be used in the future to add new fields and it will act as a natural ABI version indicator as well. Also adjust tools/perf/ userspace for the new definitions, noticed by Adrian Hunter. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Also-Fixed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/n/tip-zr03yxjrpXesOzzupszqglbv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-19 02:16:42 -06:00
__u32 size; /* Header size up to __reserved[] fields. */
/*
* Hole for extension of the self monitor capabilities
*/
perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page' Solve the problems around the broken definition of perf_event_mmap_page:: cap_usr_time and cap_usr_rdpmc fields which used to overlap, partially fixed by: 860f085b74e9 ("perf: Fix broken union in 'struct perf_event_mmap_page'") The problem with the fix (merged in v3.12-rc1 and not yet released officially), noticed by Vince Weaver is that the new behavior is not detectable by new user-space, and that due to the reuse of the field names it's easy to mis-compile a binary if old headers are used on a new kernel or new headers are used on an old kernel. To solve all that make this change explicit, detectable and self-contained, by iterating the ABI the following way: - Always clear bit 0, and rename it to usrpage->cap_bit0, to at least not confuse old user-space binaries. RDPMC will be marked as unavailable to old binaries but that's within the ABI, this is a capability bit. - Rename bit 1 to ->cap_bit0_is_deprecated and always set it to 1, so new libraries can reliably detect that bit 0 is deprecated and perma-zero without having to check the kernel version. - Use bits 2, 3, 4 for the newly defined, correct functionality: cap_user_rdpmc : 1, /* The RDPMC instruction can be used to read counts */ cap_user_time : 1, /* The time_* fields are used */ cap_user_time_zero : 1, /* The time_zero field is used */ - Rename all the bitfield names in perf_event.h to be different from the old names, to make sure it's not possible to mis-compile it accidentally with old assumptions. The 'size' field can then be used in the future to add new fields and it will act as a natural ABI version indicator as well. Also adjust tools/perf/ userspace for the new definitions, noticed by Adrian Hunter. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Also-Fixed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/n/tip-zr03yxjrpXesOzzupszqglbv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-19 02:16:42 -06:00
__u8 __reserved[118*8+4]; /* align to 1k. */
/*
* Control data for the mmap() data buffer.
*
* User-space reading the @data_head value should issue an smp_rmb(),
* after reading this value.
*
* When the mapping is PROT_WRITE the @data_tail value should be
* written by userspace to reflect the last read data, after issueing
* an smp_mb() to separate the data read from the ->data_tail store.
* In this case the kernel will not over-write unread data.
*
* See perf_output_put_handle() for the data ordering.
*
* data_{offset,size} indicate the location and size of the perf record
* buffer within the mmapped area.
*/
__u64 data_head; /* head in the data section */
__u64 data_tail; /* user-space written tail */
__u64 data_offset; /* where the buffer starts */
__u64 data_size; /* data buffer size */
perf: Add AUX area to ring buffer for raw data streams This patch introduces "AUX space" in the perf mmap buffer, intended for exporting high bandwidth data streams to userspace, such as instruction flow traces. AUX space is a ring buffer, defined by aux_{offset,size} fields in the user_page structure, and read/write pointers aux_{head,tail}, which abide by the same rules as data_* counterparts of the main perf buffer. In order to allocate/mmap AUX, userspace needs to set up aux_offset to such an offset that will be greater than data_offset+data_size and aux_size to be the desired buffer size. Both need to be page aligned. Then, same aux_offset and aux_size should be passed to mmap() call and if everything adds up, you should have an AUX buffer as a result. Pages that are mapped into this buffer also come out of user's mlock rlimit plus perf_event_mlock_kb allowance. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Link: http://lkml.kernel.org/r/1421237903-181015-3-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-14 05:18:11 -07:00
/*
* AUX area is defined by aux_{offset,size} fields that should be set
* by the userspace, so that
*
* aux_offset >= data_offset + data_size
*
* prior to mmap()ing it. Size of the mmap()ed area should be aux_size.
*
* Ring buffer pointers aux_{head,tail} have the same semantics as
* data_{head,tail} and same ordering rules apply.
*/
__u64 aux_head;
__u64 aux_tail;
__u64 aux_offset;
__u64 aux_size;
};
#define PERF_RECORD_MISC_CPUMODE_MASK (7 << 0)
#define PERF_RECORD_MISC_CPUMODE_UNKNOWN (0 << 0)
#define PERF_RECORD_MISC_KERNEL (1 << 0)
#define PERF_RECORD_MISC_USER (2 << 0)
#define PERF_RECORD_MISC_HYPERVISOR (3 << 0)
#define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0)
#define PERF_RECORD_MISC_GUEST_USER (5 << 0)
/*
* Indicates that /proc/PID/maps parsing are truncated by time out.
*/
#define PERF_RECORD_MISC_PROC_MAP_PARSE_TIMEOUT (1 << 12)
/*
* PERF_RECORD_MISC_MMAP_DATA and PERF_RECORD_MISC_COMM_EXEC are used on
* different events so can reuse the same bit position.
perf: Add PERF_RECORD_SWITCH to indicate context switches There are already two events for context switches, namely the tracepoint sched:sched_switch and the software event context_switches. Unfortunately neither are suitable for use by non-privileged users for the purpose of synchronizing hardware trace data (e.g. Intel PT) to the context switch. Tracepoints are no good at all for non-privileged users because they need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= -1. On the other hand, kernel software events need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= 1. Now many distributions do default perf_event_paranoid to 1 making context_switches a contender, except it has another problem (which is also shared with sched:sched_switch) which is that it happens before perf schedules events out instead of after perf schedules events in. Whereas a privileged user can see all the events anyway, a non-privileged user only sees events for their own processes, in other words they see when their process was scheduled out not when it was scheduled in. That presents two problems to use the event: 1. the information comes too late, so tools have to look ahead in the event stream to find out what the current state is 2. if they are unlucky tracing might have stopped before the context-switches event is recorded. This new PERF_RECORD_SWITCH event does not have those problems and it also has a couple of other small advantages. It is easier to use because it is an auxiliary event (like mmap, comm and task events) which can be enabled by setting a single bit. It is smaller than sched:sched_switch and easier to parse. To make the event useful for privileged users also, if the context is cpu-wide then the event record will be PERF_RECORD_SWITCH_CPU_WIDE which is the same as PERF_RECORD_SWITCH except it also provides the next or previous pid/tid. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1437471846-26995-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-21 03:44:02 -06:00
* Ditto PERF_RECORD_MISC_SWITCH_OUT.
*/
#define PERF_RECORD_MISC_MMAP_DATA (1 << 13)
#define PERF_RECORD_MISC_COMM_EXEC (1 << 13)
perf: Add PERF_RECORD_SWITCH to indicate context switches There are already two events for context switches, namely the tracepoint sched:sched_switch and the software event context_switches. Unfortunately neither are suitable for use by non-privileged users for the purpose of synchronizing hardware trace data (e.g. Intel PT) to the context switch. Tracepoints are no good at all for non-privileged users because they need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= -1. On the other hand, kernel software events need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= 1. Now many distributions do default perf_event_paranoid to 1 making context_switches a contender, except it has another problem (which is also shared with sched:sched_switch) which is that it happens before perf schedules events out instead of after perf schedules events in. Whereas a privileged user can see all the events anyway, a non-privileged user only sees events for their own processes, in other words they see when their process was scheduled out not when it was scheduled in. That presents two problems to use the event: 1. the information comes too late, so tools have to look ahead in the event stream to find out what the current state is 2. if they are unlucky tracing might have stopped before the context-switches event is recorded. This new PERF_RECORD_SWITCH event does not have those problems and it also has a couple of other small advantages. It is easier to use because it is an auxiliary event (like mmap, comm and task events) which can be enabled by setting a single bit. It is smaller than sched:sched_switch and easier to parse. To make the event useful for privileged users also, if the context is cpu-wide then the event record will be PERF_RECORD_SWITCH_CPU_WIDE which is the same as PERF_RECORD_SWITCH except it also provides the next or previous pid/tid. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1437471846-26995-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-21 03:44:02 -06:00
#define PERF_RECORD_MISC_SWITCH_OUT (1 << 13)
/*
* Indicates that the content of PERF_SAMPLE_IP points to
* the actual instruction that triggered the event. See also
* perf_event_attr::precise_ip.
*/
#define PERF_RECORD_MISC_EXACT_IP (1 << 14)
/*
* Reserve the last bit to indicate some extended misc field
*/
#define PERF_RECORD_MISC_EXT_RESERVED (1 << 15)
struct perf_event_header {
__u32 type;
__u16 misc;
__u16 size;
};
enum perf_event_type {
/*
* If perf_event_attr.sample_id_all is set then all event types will
* have the sample_type selected fields related to where/when
perf: make events stream always parsable The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-27 02:23:07 -06:00
* (identity) an event took place (TID, TIME, ID, STREAM_ID, CPU,
* IDENTIFIER) described in PERF_RECORD_SAMPLE below, it will be stashed
* just after the perf_event_header and the fields already present for
* the existing fields, i.e. at the end of the payload. That way a newer
* perf.data file will be supported by older perf tools, with these new
* optional fields being ignored.
*
* struct sample_id {
* { u32 pid, tid; } && PERF_SAMPLE_TID
* { u64 time; } && PERF_SAMPLE_TIME
* { u64 id; } && PERF_SAMPLE_ID
* { u64 stream_id;} && PERF_SAMPLE_STREAM_ID
* { u32 cpu, res; } && PERF_SAMPLE_CPU
perf: make events stream always parsable The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-27 02:23:07 -06:00
* { u64 id; } && PERF_SAMPLE_IDENTIFIER
* } && perf_event_attr::sample_id_all
perf: make events stream always parsable The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-27 02:23:07 -06:00
*
* Note that PERF_SAMPLE_IDENTIFIER duplicates PERF_SAMPLE_ID. The
* advantage of PERF_SAMPLE_IDENTIFIER is that its position is fixed
* relative to header.size.
*/
/*
* The MMAP events record the PROT_EXEC mappings so that we can
* correlate userspace IPs to code. They have the following structure:
*
* struct {
* struct perf_event_header header;
*
* u32 pid, tid;
* u64 addr;
* u64 len;
* u64 pgoff;
* char filename[];
* struct sample_id sample_id;
* };
*/
PERF_RECORD_MMAP = 1,
/*
* struct {
* struct perf_event_header header;
* u64 id;
* u64 lost;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_LOST = 2,
/*
* struct {
* struct perf_event_header header;
*
* u32 pid, tid;
* char comm[];
* struct sample_id sample_id;
* };
*/
PERF_RECORD_COMM = 3,
/*
* struct {
* struct perf_event_header header;
* u32 pid, ppid;
* u32 tid, ptid;
* u64 time;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_EXIT = 4,
/*
* struct {
* struct perf_event_header header;
* u64 time;
* u64 id;
* u64 stream_id;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_THROTTLE = 5,
PERF_RECORD_UNTHROTTLE = 6,
/*
* struct {
* struct perf_event_header header;
* u32 pid, ppid;
* u32 tid, ptid;
* u64 time;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_FORK = 7,
/*
* struct {
* struct perf_event_header header;
* u32 pid, tid;
*
* struct read_format values;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_READ = 8,
/*
* struct {
* struct perf_event_header header;
*
perf: make events stream always parsable The event stream is not always parsable because the format of a sample is dependent on the sample_type of the selected event. When there is more than one selected event and the sample_types are not the same then parsing becomes problematic. A sample can be matched to its selected event using the ID that is allocated when the event is opened. Unfortunately, to get the ID from the sample means first parsing it. This patch adds a new sample format bit PERF_SAMPLE_IDENTIFER that puts the ID at a fixed position so that the ID can be retrieved without parsing the sample. For sample events, that is the first position immediately after the header. For non-sample events, that is the last position. In this respect parsing samples requires that the sample_type and ID values are recorded. For example, perf tools records struct perf_event_attr and the IDs within the perf.data file. Those must be read first before it is possible to parse samples found later in the perf.data file. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Tested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1377591794-30553-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-27 02:23:07 -06:00
* #
* # Note that PERF_SAMPLE_IDENTIFIER duplicates PERF_SAMPLE_ID.
* # The advantage of PERF_SAMPLE_IDENTIFIER is that its position
* # is fixed relative to header.
* #
*
* { u64 id; } && PERF_SAMPLE_IDENTIFIER
* { u64 ip; } && PERF_SAMPLE_IP
* { u32 pid, tid; } && PERF_SAMPLE_TID
* { u64 time; } && PERF_SAMPLE_TIME
* { u64 addr; } && PERF_SAMPLE_ADDR
* { u64 id; } && PERF_SAMPLE_ID
* { u64 stream_id;} && PERF_SAMPLE_STREAM_ID
* { u32 cpu, res; } && PERF_SAMPLE_CPU
* { u64 period; } && PERF_SAMPLE_PERIOD
*
* { struct read_format values; } && PERF_SAMPLE_READ
*
* { u64 nr,
* u64 ips[nr]; } && PERF_SAMPLE_CALLCHAIN
*
* #
* # The RAW record below is opaque data wrt the ABI
* #
* # That is, the ABI doesn't make any promises wrt to
* # the stability of its content, it may vary depending
* # on event, hardware, kernel version and phase of
* # the moon.
* #
* # In other words, PERF_SAMPLE_RAW contents are not an ABI.
* #
*
* { u32 size;
* char data[size];}&& PERF_SAMPLE_RAW
*
* { u64 nr;
* { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
*
* { u64 abi; # enum perf_sample_regs_abi
* u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER
*
* { u64 size;
* char data[size];
* u64 dyn_size; } && PERF_SAMPLE_STACK_USER
*
* { u64 weight; } && PERF_SAMPLE_WEIGHT
* { u64 data_src; } && PERF_SAMPLE_DATA_SRC
* { u64 transaction; } && PERF_SAMPLE_TRANSACTION
* { u64 abi; # enum perf_sample_regs_abi
* u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
* };
*/
PERF_RECORD_SAMPLE = 9,
/*
* The MMAP2 records are an augmented version of MMAP, they add
* maj, min, ino numbers to be used to uniquely identify each mapping
*
* struct {
* struct perf_event_header header;
*
* u32 pid, tid;
* u64 addr;
* u64 len;
* u64 pgoff;
* u32 maj;
* u32 min;
* u64 ino;
* u64 ino_generation;
* u32 prot, flags;
* char filename[];
* struct sample_id sample_id;
* };
*/
PERF_RECORD_MMAP2 = 10,
/*
* Records that new data landed in the AUX buffer part.
*
* struct {
* struct perf_event_header header;
*
* u64 aux_offset;
* u64 aux_size;
* u64 flags;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_AUX = 11,
perf: Add ITRACE_START record to indicate that tracing has started For counters that generate AUX data that is bound to the context of a running task, such as instruction tracing, the decoder needs to know exactly which task is running when the event is first scheduled in, before the first sched_switch. The decoder's need to know this stems from the fact that instruction flow trace decoding will almost always require program's object code in order to reconstruct said flow and for that we need at least its pid/tid in the perf stream. To single out such instruction tracing pmus, this patch introduces ITRACE PMU capability. The reason this is not part of RECORD_AUX record is that not all pmus capable of generating AUX data need this, and the opposite is *probably* also true. While sched_switch covers for most cases, there are two problems with it: the consumer will need to process events out of order (that is, having found RECORD_AUX, it will have to skip forward to the nearest sched_switch to figure out which task it was, then go back to the actual trace to decode it) and it completely misses the case when the tracing is enabled and disabled before sched_switch, for example, via PERF_EVENT_IOC_DISABLE. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Link: http://lkml.kernel.org/r/1421237903-181015-15-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-14 05:18:23 -07:00
/*
* Indicates that instruction trace has started
*
* struct {
* struct perf_event_header header;
* u32 pid;
* u32 tid;
* };
*/
PERF_RECORD_ITRACE_START = 12,
/*
* Records the dropped/lost sample number.
*
* struct {
* struct perf_event_header header;
*
* u64 lost;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_LOST_SAMPLES = 13,
perf: Add PERF_RECORD_SWITCH to indicate context switches There are already two events for context switches, namely the tracepoint sched:sched_switch and the software event context_switches. Unfortunately neither are suitable for use by non-privileged users for the purpose of synchronizing hardware trace data (e.g. Intel PT) to the context switch. Tracepoints are no good at all for non-privileged users because they need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= -1. On the other hand, kernel software events need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= 1. Now many distributions do default perf_event_paranoid to 1 making context_switches a contender, except it has another problem (which is also shared with sched:sched_switch) which is that it happens before perf schedules events out instead of after perf schedules events in. Whereas a privileged user can see all the events anyway, a non-privileged user only sees events for their own processes, in other words they see when their process was scheduled out not when it was scheduled in. That presents two problems to use the event: 1. the information comes too late, so tools have to look ahead in the event stream to find out what the current state is 2. if they are unlucky tracing might have stopped before the context-switches event is recorded. This new PERF_RECORD_SWITCH event does not have those problems and it also has a couple of other small advantages. It is easier to use because it is an auxiliary event (like mmap, comm and task events) which can be enabled by setting a single bit. It is smaller than sched:sched_switch and easier to parse. To make the event useful for privileged users also, if the context is cpu-wide then the event record will be PERF_RECORD_SWITCH_CPU_WIDE which is the same as PERF_RECORD_SWITCH except it also provides the next or previous pid/tid. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1437471846-26995-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-21 03:44:02 -06:00
/*
* Records a context switch in or out (flagged by
* PERF_RECORD_MISC_SWITCH_OUT). See also
* PERF_RECORD_SWITCH_CPU_WIDE.
*
* struct {
* struct perf_event_header header;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_SWITCH = 14,
/*
* CPU-wide version of PERF_RECORD_SWITCH with next_prev_pid and
* next_prev_tid that are the next (switching out) or previous
* (switching in) pid/tid.
*
* struct {
* struct perf_event_header header;
* u32 next_prev_pid;
* u32 next_prev_tid;
* struct sample_id sample_id;
* };
*/
PERF_RECORD_SWITCH_CPU_WIDE = 15,
PERF_RECORD_MAX, /* non-ABI */
};
#define PERF_MAX_STACK_DEPTH 127
perf core: Separate accounting of contexts and real addresses in a stack trace The perf_sample->ip_callchain->nr value includes all the entries in the ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc}, while what the user expects is that what is in the kernel.perf_event_max_stack sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be honoured in terms of IP addresses in the stack trace. So allocate a bunch of extra entries for contexts, and do the accounting via perf_callchain_entry_ctx struct members. A new sysctl, kernel.perf_event_max_contexts_per_stack is also introduced for investigating possible bugs in the callchain implementation by some arch. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-3b4wnqk340c4sg4gwkfdi9yk@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-12 10:06:21 -06:00
#define PERF_MAX_CONTEXTS_PER_STACK 8
enum perf_callchain_context {
PERF_CONTEXT_HV = (__u64)-32,
PERF_CONTEXT_KERNEL = (__u64)-128,
PERF_CONTEXT_USER = (__u64)-512,
PERF_CONTEXT_GUEST = (__u64)-2048,
PERF_CONTEXT_GUEST_KERNEL = (__u64)-2176,
PERF_CONTEXT_GUEST_USER = (__u64)-2560,
PERF_CONTEXT_MAX = (__u64)-4095,
};
/**
* PERF_RECORD_AUX::flags bits
*/
#define PERF_AUX_FLAG_TRUNCATED 0x01 /* record was truncated to fit */
perf: Support overwrite mode for the AUX area This adds support for overwrite mode in the AUX area, which means "keep collecting data till you're stopped", turning AUX area into a circular buffer, where new data overwrites old data. It does not depend on data buffer's overwrite mode, so that it doesn't lose sideband data that is instrumental for processing AUX data. Overwrite mode is enabled at mapping AUX area read only. Even though aux_tail in the buffer's user page might be user writable, it will be ignored in this mode. A PERF_RECORD_AUX with PERF_AUX_FLAG_OVERWRITE set is written to the perf data stream every time an event writes new data to the AUX area. The pmu driver might not be able to infer the exact beginning of the new data in each snapshot, some drivers will only provide the tail, which is aux_offset + aux_size in the AUX record. Consumer has to be able to tell the new data from the old one, for example, by means of time stamps if such are provided in the trace. Consumer is also responsible for disabling any events that might write to the AUX area (thus potentially racing with the consumer) before collecting the data. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kaixu Xia <kaixu.xia@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@infradead.org Cc: adrian.hunter@intel.com Cc: kan.liang@intel.com Cc: markus.t.metzger@intel.com Cc: mathieu.poirier@linaro.org Link: http://lkml.kernel.org/r/1421237903-181015-9-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-14 05:18:17 -07:00
#define PERF_AUX_FLAG_OVERWRITE 0x02 /* snapshot from overwrite mode */
#define PERF_FLAG_FD_NO_GROUP (1UL << 0)
#define PERF_FLAG_FD_OUTPUT (1UL << 1)
#define PERF_FLAG_PID_CGROUP (1UL << 2) /* pid=cgroup id, per-cpu mode only */
#define PERF_FLAG_FD_CLOEXEC (1UL << 3) /* O_CLOEXEC */
union perf_mem_data_src {
__u64 val;
struct {
__u64 mem_op:5, /* type of opcode */
mem_lvl:14, /* memory hierarchy level */
mem_snoop:5, /* snoop mode */
mem_lock:2, /* lock instr */
mem_dtlb:7, /* tlb access */
mem_rsvd:31;
};
};
/* type of opcode (load/store/prefetch,code) */
#define PERF_MEM_OP_NA 0x01 /* not available */
#define PERF_MEM_OP_LOAD 0x02 /* load instruction */
#define PERF_MEM_OP_STORE 0x04 /* store instruction */
#define PERF_MEM_OP_PFETCH 0x08 /* prefetch */
#define PERF_MEM_OP_EXEC 0x10 /* code (execution) */
#define PERF_MEM_OP_SHIFT 0
/* memory hierarchy (memory level, hit or miss) */
#define PERF_MEM_LVL_NA 0x01 /* not available */
#define PERF_MEM_LVL_HIT 0x02 /* hit level */
#define PERF_MEM_LVL_MISS 0x04 /* miss level */
#define PERF_MEM_LVL_L1 0x08 /* L1 */
#define PERF_MEM_LVL_LFB 0x10 /* Line Fill Buffer */
#define PERF_MEM_LVL_L2 0x20 /* L2 */
#define PERF_MEM_LVL_L3 0x40 /* L3 */
#define PERF_MEM_LVL_LOC_RAM 0x80 /* Local DRAM */
#define PERF_MEM_LVL_REM_RAM1 0x100 /* Remote DRAM (1 hop) */
#define PERF_MEM_LVL_REM_RAM2 0x200 /* Remote DRAM (2 hops) */
#define PERF_MEM_LVL_REM_CCE1 0x400 /* Remote Cache (1 hop) */
#define PERF_MEM_LVL_REM_CCE2 0x800 /* Remote Cache (2 hops) */
#define PERF_MEM_LVL_IO 0x1000 /* I/O memory */
#define PERF_MEM_LVL_UNC 0x2000 /* Uncached memory */
#define PERF_MEM_LVL_SHIFT 5
/* snoop mode */
#define PERF_MEM_SNOOP_NA 0x01 /* not available */
#define PERF_MEM_SNOOP_NONE 0x02 /* no snoop */
#define PERF_MEM_SNOOP_HIT 0x04 /* snoop hit */
#define PERF_MEM_SNOOP_MISS 0x08 /* snoop miss */
#define PERF_MEM_SNOOP_HITM 0x10 /* snoop hit modified */
#define PERF_MEM_SNOOP_SHIFT 19
/* locked instruction */
#define PERF_MEM_LOCK_NA 0x01 /* not available */
#define PERF_MEM_LOCK_LOCKED 0x02 /* locked transaction */
#define PERF_MEM_LOCK_SHIFT 24
/* TLB access */
#define PERF_MEM_TLB_NA 0x01 /* not available */
#define PERF_MEM_TLB_HIT 0x02 /* hit level */
#define PERF_MEM_TLB_MISS 0x04 /* miss level */
#define PERF_MEM_TLB_L1 0x08 /* L1 */
#define PERF_MEM_TLB_L2 0x10 /* L2 */
#define PERF_MEM_TLB_WK 0x20 /* Hardware Walker*/
#define PERF_MEM_TLB_OS 0x40 /* OS fault handler */
#define PERF_MEM_TLB_SHIFT 26
#define PERF_MEM_S(a, s) \
(((__u64)PERF_MEM_##a##_##s) << PERF_MEM_##a##_SHIFT)
/*
* single taken branch record layout:
*
* from: source instruction (may not always be a branch insn)
* to: branch target
* mispred: branch target was mispredicted
* predicted: branch target was predicted
*
* support for mispred, predicted is optional. In case it
* is not supported mispred = predicted = 0.
*
* in_tx: running in a hardware transaction
* abort: aborting a hardware transaction
* cycles: cycles from last branch (or 0 if not supported)
*/
struct perf_branch_entry {
__u64 from;
__u64 to;
__u64 mispred:1, /* target mispredicted */
predicted:1,/* target predicted */
in_tx:1, /* in transaction */
abort:1, /* transaction abort */
cycles:16, /* cycle count to last branch */
reserved:44;
};
#endif /* _UAPI_LINUX_PERF_EVENT_H */