2008-12-04 12:12:29 -07:00
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/*
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* Performance counter core code
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*
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* Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
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* Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
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*
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* For licencing details see kernel-base/COPYING
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*/
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#include <linux/fs.h>
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#include <linux/cpu.h>
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#include <linux/smp.h>
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2008-12-11 00:38:42 -07:00
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#include <linux/file.h>
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2008-12-04 12:12:29 -07:00
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#include <linux/poll.h>
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#include <linux/sysfs.h>
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#include <linux/ptrace.h>
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#include <linux/percpu.h>
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#include <linux/uaccess.h>
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#include <linux/syscalls.h>
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#include <linux/anon_inodes.h>
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#include <linux/perf_counter.h>
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/*
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* Each CPU has a list of per CPU counters:
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*/
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DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
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int perf_max_counters __read_mostly;
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static int perf_reserved_percpu __read_mostly;
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static int perf_overcommit __read_mostly = 1;
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/*
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* Mutex for (sysadmin-configurable) counter reservations:
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*/
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static DEFINE_MUTEX(perf_resource_mutex);
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/*
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* Architecture provided APIs - weak aliases:
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*/
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2008-12-11 05:21:10 -07:00
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extern __weak const struct hw_perf_counter_ops *
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2008-12-11 04:46:46 -07:00
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hw_perf_counter_init(struct perf_counter *counter)
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2008-12-04 12:12:29 -07:00
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{
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2008-12-11 04:46:46 -07:00
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return ERR_PTR(-EINVAL);
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2008-12-04 12:12:29 -07:00
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}
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2008-12-11 05:45:51 -07:00
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u64 __weak hw_perf_save_disable(void) { return 0; }
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void __weak hw_perf_restore(u64 ctrl) { }
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2008-12-11 05:21:10 -07:00
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void __weak hw_perf_counter_setup(void) { }
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2008-12-04 12:12:29 -07:00
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#if BITS_PER_LONG == 64
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/*
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* Read the cached counter in counter safe against cross CPU / NMI
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* modifications. 64 bit version - no complications.
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*/
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2008-12-11 00:38:42 -07:00
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static inline u64 perf_counter_read_safe(struct perf_counter *counter)
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2008-12-04 12:12:29 -07:00
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{
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return (u64) atomic64_read(&counter->count);
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}
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2008-12-11 05:21:10 -07:00
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void atomic64_counter_set(struct perf_counter *counter, u64 val)
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{
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atomic64_set(&counter->count, val);
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}
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u64 atomic64_counter_read(struct perf_counter *counter)
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{
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return atomic64_read(&counter->count);
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}
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2008-12-04 12:12:29 -07:00
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#else
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/*
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* Read the cached counter in counter safe against cross CPU / NMI
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* modifications. 32 bit version.
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*/
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2008-12-11 00:38:42 -07:00
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static u64 perf_counter_read_safe(struct perf_counter *counter)
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2008-12-04 12:12:29 -07:00
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{
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u32 cntl, cnth;
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local_irq_disable();
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do {
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cnth = atomic_read(&counter->count32[1]);
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cntl = atomic_read(&counter->count32[0]);
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} while (cnth != atomic_read(&counter->count32[1]));
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local_irq_enable();
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return cntl | ((u64) cnth) << 32;
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}
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2008-12-11 05:21:10 -07:00
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void atomic64_counter_set(struct perf_counter *counter, u64 val64)
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{
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u32 *val32 = (void *)&val64;
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atomic_set(counter->count32 + 0, *(val32 + 0));
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atomic_set(counter->count32 + 1, *(val32 + 1));
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}
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u64 atomic64_counter_read(struct perf_counter *counter)
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{
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return atomic_read(counter->count32 + 0) |
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(u64) atomic_read(counter->count32 + 1) << 32;
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}
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2008-12-04 12:12:29 -07:00
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#endif
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2008-12-11 00:38:42 -07:00
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static void
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list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
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{
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struct perf_counter *group_leader = counter->group_leader;
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/*
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* Depending on whether it is a standalone or sibling counter,
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* add it straight to the context's counter list, or to the group
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* leader's sibling list:
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*/
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if (counter->group_leader == counter)
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list_add_tail(&counter->list_entry, &ctx->counter_list);
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else
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list_add_tail(&counter->list_entry, &group_leader->sibling_list);
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}
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static void
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list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
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{
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struct perf_counter *sibling, *tmp;
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list_del_init(&counter->list_entry);
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/*
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* If this was a group counter with sibling counters then
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* upgrade the siblings to singleton counters by adding them
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* to the context list directly:
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*/
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list_for_each_entry_safe(sibling, tmp,
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&counter->sibling_list, list_entry) {
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list_del_init(&sibling->list_entry);
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list_add_tail(&sibling->list_entry, &ctx->counter_list);
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WARN_ON_ONCE(!sibling->group_leader);
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WARN_ON_ONCE(sibling->group_leader == sibling);
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sibling->group_leader = sibling;
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}
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}
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2008-12-04 12:12:29 -07:00
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/*
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* Cross CPU call to remove a performance counter
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*
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* We disable the counter on the hardware level first. After that we
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* remove it from the context list.
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*/
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2008-12-11 00:38:42 -07:00
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static void __perf_counter_remove_from_context(void *info)
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2008-12-04 12:12:29 -07:00
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{
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struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
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struct perf_counter *counter = info;
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struct perf_counter_context *ctx = counter->ctx;
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2008-12-11 05:21:10 -07:00
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u64 perf_flags;
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2008-12-04 12:12:29 -07:00
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/*
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* If this is a task context, we need to check whether it is
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* the current task context of this cpu. If not it has been
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* scheduled out before the smp call arrived.
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*/
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if (ctx->task && cpuctx->task_ctx != ctx)
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return;
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spin_lock(&ctx->lock);
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if (counter->active) {
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2008-12-11 04:46:46 -07:00
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counter->hw_ops->hw_perf_counter_disable(counter);
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2008-12-04 12:12:29 -07:00
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counter->active = 0;
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ctx->nr_active--;
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cpuctx->active_oncpu--;
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counter->task = NULL;
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}
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ctx->nr_counters--;
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/*
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* Protect the list operation against NMI by disabling the
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* counters on a global level. NOP for non NMI based counters.
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*/
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2008-12-11 05:45:51 -07:00
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perf_flags = hw_perf_save_disable();
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2008-12-11 00:38:42 -07:00
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list_del_counter(counter, ctx);
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2008-12-11 05:45:51 -07:00
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hw_perf_restore(perf_flags);
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2008-12-04 12:12:29 -07:00
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if (!ctx->task) {
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/*
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* Allow more per task counters with respect to the
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* reservation:
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*/
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cpuctx->max_pertask =
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min(perf_max_counters - ctx->nr_counters,
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perf_max_counters - perf_reserved_percpu);
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}
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spin_unlock(&ctx->lock);
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}
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/*
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* Remove the counter from a task's (or a CPU's) list of counters.
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*
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* Must be called with counter->mutex held.
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*
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* CPU counters are removed with a smp call. For task counters we only
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* call when the task is on a CPU.
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*/
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2008-12-11 00:38:42 -07:00
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static void perf_counter_remove_from_context(struct perf_counter *counter)
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2008-12-04 12:12:29 -07:00
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{
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struct perf_counter_context *ctx = counter->ctx;
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struct task_struct *task = ctx->task;
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if (!task) {
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/*
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* Per cpu counters are removed via an smp call and
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* the removal is always sucessful.
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*/
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smp_call_function_single(counter->cpu,
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2008-12-11 00:38:42 -07:00
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__perf_counter_remove_from_context,
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2008-12-04 12:12:29 -07:00
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counter, 1);
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return;
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}
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retry:
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2008-12-11 00:38:42 -07:00
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task_oncpu_function_call(task, __perf_counter_remove_from_context,
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2008-12-04 12:12:29 -07:00
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counter);
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spin_lock_irq(&ctx->lock);
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/*
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* If the context is active we need to retry the smp call.
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*/
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2008-12-11 00:38:42 -07:00
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if (ctx->nr_active && !list_empty(&counter->list_entry)) {
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2008-12-04 12:12:29 -07:00
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spin_unlock_irq(&ctx->lock);
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goto retry;
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}
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/*
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* The lock prevents that this context is scheduled in so we
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2008-12-11 00:38:42 -07:00
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* can remove the counter safely, if the call above did not
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2008-12-04 12:12:29 -07:00
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* succeed.
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*/
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2008-12-11 00:38:42 -07:00
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if (!list_empty(&counter->list_entry)) {
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2008-12-04 12:12:29 -07:00
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ctx->nr_counters--;
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2008-12-11 00:38:42 -07:00
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list_del_counter(counter, ctx);
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2008-12-04 12:12:29 -07:00
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counter->task = NULL;
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}
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spin_unlock_irq(&ctx->lock);
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}
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/*
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* Cross CPU call to install and enable a preformance counter
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*/
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static void __perf_install_in_context(void *info)
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{
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struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
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struct perf_counter *counter = info;
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struct perf_counter_context *ctx = counter->ctx;
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int cpu = smp_processor_id();
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2008-12-11 05:21:10 -07:00
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u64 perf_flags;
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2008-12-04 12:12:29 -07:00
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/*
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* If this is a task context, we need to check whether it is
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* the current task context of this cpu. If not it has been
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* scheduled out before the smp call arrived.
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*/
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if (ctx->task && cpuctx->task_ctx != ctx)
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return;
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spin_lock(&ctx->lock);
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/*
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* Protect the list operation against NMI by disabling the
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* counters on a global level. NOP for non NMI based counters.
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*/
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2008-12-11 05:45:51 -07:00
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perf_flags = hw_perf_save_disable();
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2008-12-11 00:38:42 -07:00
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list_add_counter(counter, ctx);
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2008-12-11 05:45:51 -07:00
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hw_perf_restore(perf_flags);
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2008-12-04 12:12:29 -07:00
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ctx->nr_counters++;
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if (cpuctx->active_oncpu < perf_max_counters) {
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2008-12-11 04:46:46 -07:00
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counter->hw_ops->hw_perf_counter_enable(counter);
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2008-12-04 12:12:29 -07:00
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counter->active = 1;
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counter->oncpu = cpu;
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ctx->nr_active++;
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cpuctx->active_oncpu++;
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}
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if (!ctx->task && cpuctx->max_pertask)
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cpuctx->max_pertask--;
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spin_unlock(&ctx->lock);
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}
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/*
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* Attach a performance counter to a context
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*
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* First we add the counter to the list with the hardware enable bit
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* in counter->hw_config cleared.
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*
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* If the counter is attached to a task which is on a CPU we use a smp
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* call to enable it in the task context. The task might have been
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* scheduled away, but we check this in the smp call again.
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*/
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static void
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perf_install_in_context(struct perf_counter_context *ctx,
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struct perf_counter *counter,
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int cpu)
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{
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struct task_struct *task = ctx->task;
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counter->ctx = ctx;
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if (!task) {
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/*
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* Per cpu counters are installed via an smp call and
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* the install is always sucessful.
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*/
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smp_call_function_single(cpu, __perf_install_in_context,
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counter, 1);
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return;
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}
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counter->task = task;
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retry:
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task_oncpu_function_call(task, __perf_install_in_context,
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counter);
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spin_lock_irq(&ctx->lock);
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/*
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* If the context is active and the counter has not been added
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* we need to retry the smp call.
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*/
|
2008-12-11 00:38:42 -07:00
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if (ctx->nr_active && list_empty(&counter->list_entry)) {
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2008-12-04 12:12:29 -07:00
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spin_unlock_irq(&ctx->lock);
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goto retry;
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}
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/*
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* The lock prevents that this context is scheduled in so we
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* can add the counter safely, if it the call above did not
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* succeed.
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*/
|
2008-12-11 00:38:42 -07:00
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if (list_empty(&counter->list_entry)) {
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list_add_counter(counter, ctx);
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2008-12-04 12:12:29 -07:00
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ctx->nr_counters++;
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}
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spin_unlock_irq(&ctx->lock);
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}
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2008-12-11 00:38:42 -07:00
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static void
|
|
|
|
counter_sched_out(struct perf_counter *counter,
|
|
|
|
struct perf_cpu_context *cpuctx,
|
|
|
|
struct perf_counter_context *ctx)
|
|
|
|
{
|
|
|
|
if (!counter->active)
|
|
|
|
return;
|
|
|
|
|
2008-12-11 04:46:46 -07:00
|
|
|
counter->hw_ops->hw_perf_counter_disable(counter);
|
2008-12-11 00:38:42 -07:00
|
|
|
counter->active = 0;
|
|
|
|
counter->oncpu = -1;
|
|
|
|
|
|
|
|
cpuctx->active_oncpu--;
|
|
|
|
ctx->nr_active--;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
group_sched_out(struct perf_counter *group_counter,
|
|
|
|
struct perf_cpu_context *cpuctx,
|
|
|
|
struct perf_counter_context *ctx)
|
|
|
|
{
|
|
|
|
struct perf_counter *counter;
|
|
|
|
|
|
|
|
counter_sched_out(group_counter, cpuctx, ctx);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Schedule out siblings (if any):
|
|
|
|
*/
|
|
|
|
list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
|
|
|
|
counter_sched_out(counter, cpuctx, ctx);
|
|
|
|
}
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
/*
|
|
|
|
* Called from scheduler to remove the counters of the current task,
|
|
|
|
* with interrupts disabled.
|
|
|
|
*
|
|
|
|
* We stop each counter and update the counter value in counter->count.
|
|
|
|
*
|
|
|
|
* This does not protect us against NMI, but hw_perf_counter_disable()
|
|
|
|
* sets the disabled bit in the control field of counter _before_
|
|
|
|
* accessing the counter control register. If a NMI hits, then it will
|
|
|
|
* not restart the counter.
|
|
|
|
*/
|
|
|
|
void perf_counter_task_sched_out(struct task_struct *task, int cpu)
|
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
|
|
|
|
struct perf_counter_context *ctx = &task->perf_counter_ctx;
|
|
|
|
struct perf_counter *counter;
|
|
|
|
|
|
|
|
if (likely(!cpuctx->task_ctx))
|
|
|
|
return;
|
|
|
|
|
|
|
|
spin_lock(&ctx->lock);
|
2008-12-11 00:38:42 -07:00
|
|
|
if (ctx->nr_active) {
|
|
|
|
list_for_each_entry(counter, &ctx->counter_list, list_entry)
|
|
|
|
group_sched_out(counter, cpuctx, ctx);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
spin_unlock(&ctx->lock);
|
|
|
|
cpuctx->task_ctx = NULL;
|
|
|
|
}
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
static void
|
|
|
|
counter_sched_in(struct perf_counter *counter,
|
|
|
|
struct perf_cpu_context *cpuctx,
|
|
|
|
struct perf_counter_context *ctx,
|
|
|
|
int cpu)
|
|
|
|
{
|
2008-12-11 04:46:46 -07:00
|
|
|
counter->hw_ops->hw_perf_counter_enable(counter);
|
2008-12-11 00:38:42 -07:00
|
|
|
counter->active = 1;
|
|
|
|
counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */
|
|
|
|
|
|
|
|
cpuctx->active_oncpu++;
|
|
|
|
ctx->nr_active++;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
group_sched_in(struct perf_counter *group_counter,
|
|
|
|
struct perf_cpu_context *cpuctx,
|
|
|
|
struct perf_counter_context *ctx,
|
|
|
|
int cpu)
|
|
|
|
{
|
|
|
|
struct perf_counter *counter;
|
|
|
|
|
|
|
|
counter_sched_in(group_counter, cpuctx, ctx, cpu);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Schedule in siblings as one group (if any):
|
|
|
|
*/
|
|
|
|
list_for_each_entry(counter, &group_counter->sibling_list, list_entry)
|
|
|
|
counter_sched_in(counter, cpuctx, ctx, cpu);
|
|
|
|
}
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
/*
|
|
|
|
* Called from scheduler to add the counters of the current task
|
|
|
|
* with interrupts disabled.
|
|
|
|
*
|
|
|
|
* We restore the counter value and then enable it.
|
|
|
|
*
|
|
|
|
* This does not protect us against NMI, but hw_perf_counter_enable()
|
|
|
|
* sets the enabled bit in the control field of counter _before_
|
|
|
|
* accessing the counter control register. If a NMI hits, then it will
|
|
|
|
* keep the counter running.
|
|
|
|
*/
|
|
|
|
void perf_counter_task_sched_in(struct task_struct *task, int cpu)
|
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
|
|
|
|
struct perf_counter_context *ctx = &task->perf_counter_ctx;
|
|
|
|
struct perf_counter *counter;
|
|
|
|
|
|
|
|
if (likely(!ctx->nr_counters))
|
|
|
|
return;
|
|
|
|
|
|
|
|
spin_lock(&ctx->lock);
|
2008-12-11 00:38:42 -07:00
|
|
|
list_for_each_entry(counter, &ctx->counter_list, list_entry) {
|
2008-12-04 12:12:29 -07:00
|
|
|
if (ctx->nr_active == cpuctx->max_pertask)
|
|
|
|
break;
|
2008-12-11 00:38:42 -07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Listen to the 'cpu' scheduling filter constraint
|
|
|
|
* of counters:
|
|
|
|
*/
|
2008-12-04 12:12:29 -07:00
|
|
|
if (counter->cpu != -1 && counter->cpu != cpu)
|
|
|
|
continue;
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
group_sched_in(counter, cpuctx, ctx, cpu);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
spin_unlock(&ctx->lock);
|
2008-12-11 00:38:42 -07:00
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
cpuctx->task_ctx = ctx;
|
|
|
|
}
|
|
|
|
|
|
|
|
void perf_counter_task_tick(struct task_struct *curr, int cpu)
|
|
|
|
{
|
|
|
|
struct perf_counter_context *ctx = &curr->perf_counter_ctx;
|
|
|
|
struct perf_counter *counter;
|
2008-12-11 05:21:10 -07:00
|
|
|
u64 perf_flags;
|
2008-12-04 12:12:29 -07:00
|
|
|
|
|
|
|
if (likely(!ctx->nr_counters))
|
|
|
|
return;
|
|
|
|
|
|
|
|
perf_counter_task_sched_out(curr, cpu);
|
|
|
|
|
|
|
|
spin_lock(&ctx->lock);
|
|
|
|
|
|
|
|
/*
|
2008-12-11 00:38:42 -07:00
|
|
|
* Rotate the first entry last (works just fine for group counters too):
|
2008-12-04 12:12:29 -07:00
|
|
|
*/
|
2008-12-11 05:45:51 -07:00
|
|
|
perf_flags = hw_perf_save_disable();
|
2008-12-11 00:38:42 -07:00
|
|
|
list_for_each_entry(counter, &ctx->counter_list, list_entry) {
|
|
|
|
list_del(&counter->list_entry);
|
|
|
|
list_add_tail(&counter->list_entry, &ctx->counter_list);
|
2008-12-04 12:12:29 -07:00
|
|
|
break;
|
|
|
|
}
|
2008-12-11 05:45:51 -07:00
|
|
|
hw_perf_restore(perf_flags);
|
2008-12-04 12:12:29 -07:00
|
|
|
|
|
|
|
spin_unlock(&ctx->lock);
|
|
|
|
|
|
|
|
perf_counter_task_sched_in(curr, cpu);
|
|
|
|
}
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
/*
|
|
|
|
* Initialize the perf_counter context in a task_struct:
|
|
|
|
*/
|
|
|
|
static void
|
|
|
|
__perf_counter_init_context(struct perf_counter_context *ctx,
|
|
|
|
struct task_struct *task)
|
|
|
|
{
|
|
|
|
spin_lock_init(&ctx->lock);
|
|
|
|
INIT_LIST_HEAD(&ctx->counter_list);
|
|
|
|
ctx->nr_counters = 0;
|
|
|
|
ctx->task = task;
|
|
|
|
}
|
2008-12-04 12:12:29 -07:00
|
|
|
/*
|
|
|
|
* Initialize the perf_counter context in task_struct
|
|
|
|
*/
|
|
|
|
void perf_counter_init_task(struct task_struct *task)
|
|
|
|
{
|
2008-12-11 00:38:42 -07:00
|
|
|
__perf_counter_init_context(&task->perf_counter_ctx, task);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Cross CPU call to read the hardware counter
|
|
|
|
*/
|
|
|
|
static void __hw_perf_counter_read(void *info)
|
|
|
|
{
|
2008-12-11 04:46:46 -07:00
|
|
|
struct perf_counter *counter = info;
|
|
|
|
|
|
|
|
counter->hw_ops->hw_perf_counter_read(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
static u64 perf_counter_read(struct perf_counter *counter)
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
|
|
|
/*
|
|
|
|
* If counter is enabled and currently active on a CPU, update the
|
|
|
|
* value in the counter structure:
|
|
|
|
*/
|
|
|
|
if (counter->active) {
|
|
|
|
smp_call_function_single(counter->oncpu,
|
|
|
|
__hw_perf_counter_read, counter, 1);
|
|
|
|
}
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
return perf_counter_read_safe(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Cross CPU call to switch performance data pointers
|
|
|
|
*/
|
|
|
|
static void __perf_switch_irq_data(void *info)
|
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
|
|
|
|
struct perf_counter *counter = info;
|
|
|
|
struct perf_counter_context *ctx = counter->ctx;
|
|
|
|
struct perf_data *oldirqdata = counter->irqdata;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this is a task context, we need to check whether it is
|
|
|
|
* the current task context of this cpu. If not it has been
|
|
|
|
* scheduled out before the smp call arrived.
|
|
|
|
*/
|
|
|
|
if (ctx->task) {
|
|
|
|
if (cpuctx->task_ctx != ctx)
|
|
|
|
return;
|
|
|
|
spin_lock(&ctx->lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Change the pointer NMI safe */
|
|
|
|
atomic_long_set((atomic_long_t *)&counter->irqdata,
|
|
|
|
(unsigned long) counter->usrdata);
|
|
|
|
counter->usrdata = oldirqdata;
|
|
|
|
|
|
|
|
if (ctx->task)
|
|
|
|
spin_unlock(&ctx->lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct perf_data *perf_switch_irq_data(struct perf_counter *counter)
|
|
|
|
{
|
|
|
|
struct perf_counter_context *ctx = counter->ctx;
|
|
|
|
struct perf_data *oldirqdata = counter->irqdata;
|
|
|
|
struct task_struct *task = ctx->task;
|
|
|
|
|
|
|
|
if (!task) {
|
|
|
|
smp_call_function_single(counter->cpu,
|
|
|
|
__perf_switch_irq_data,
|
|
|
|
counter, 1);
|
|
|
|
return counter->usrdata;
|
|
|
|
}
|
|
|
|
|
|
|
|
retry:
|
|
|
|
spin_lock_irq(&ctx->lock);
|
|
|
|
if (!counter->active) {
|
|
|
|
counter->irqdata = counter->usrdata;
|
|
|
|
counter->usrdata = oldirqdata;
|
|
|
|
spin_unlock_irq(&ctx->lock);
|
|
|
|
return oldirqdata;
|
|
|
|
}
|
|
|
|
spin_unlock_irq(&ctx->lock);
|
|
|
|
task_oncpu_function_call(task, __perf_switch_irq_data, counter);
|
|
|
|
/* Might have failed, because task was scheduled out */
|
|
|
|
if (counter->irqdata == oldirqdata)
|
|
|
|
goto retry;
|
|
|
|
|
|
|
|
return counter->usrdata;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void put_context(struct perf_counter_context *ctx)
|
|
|
|
{
|
|
|
|
if (ctx->task)
|
|
|
|
put_task_struct(ctx->task);
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct perf_counter_context *find_get_context(pid_t pid, int cpu)
|
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
struct perf_counter_context *ctx;
|
|
|
|
struct task_struct *task;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If cpu is not a wildcard then this is a percpu counter:
|
|
|
|
*/
|
|
|
|
if (cpu != -1) {
|
|
|
|
/* Must be root to operate on a CPU counter: */
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
|
|
return ERR_PTR(-EACCES);
|
|
|
|
|
|
|
|
if (cpu < 0 || cpu > num_possible_cpus())
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We could be clever and allow to attach a counter to an
|
|
|
|
* offline CPU and activate it when the CPU comes up, but
|
|
|
|
* that's for later.
|
|
|
|
*/
|
|
|
|
if (!cpu_isset(cpu, cpu_online_map))
|
|
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
|
|
|
|
cpuctx = &per_cpu(perf_cpu_context, cpu);
|
|
|
|
ctx = &cpuctx->ctx;
|
|
|
|
|
|
|
|
WARN_ON_ONCE(ctx->task);
|
|
|
|
return ctx;
|
|
|
|
}
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
if (!pid)
|
|
|
|
task = current;
|
|
|
|
else
|
|
|
|
task = find_task_by_vpid(pid);
|
|
|
|
if (task)
|
|
|
|
get_task_struct(task);
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
if (!task)
|
|
|
|
return ERR_PTR(-ESRCH);
|
|
|
|
|
|
|
|
ctx = &task->perf_counter_ctx;
|
|
|
|
ctx->task = task;
|
|
|
|
|
|
|
|
/* Reuse ptrace permission checks for now. */
|
|
|
|
if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
|
|
|
|
put_context(ctx);
|
|
|
|
return ERR_PTR(-EACCES);
|
|
|
|
}
|
|
|
|
|
|
|
|
return ctx;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Called when the last reference to the file is gone.
|
|
|
|
*/
|
|
|
|
static int perf_release(struct inode *inode, struct file *file)
|
|
|
|
{
|
|
|
|
struct perf_counter *counter = file->private_data;
|
|
|
|
struct perf_counter_context *ctx = counter->ctx;
|
|
|
|
|
|
|
|
file->private_data = NULL;
|
|
|
|
|
|
|
|
mutex_lock(&counter->mutex);
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
perf_counter_remove_from_context(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
put_context(ctx);
|
|
|
|
|
|
|
|
mutex_unlock(&counter->mutex);
|
|
|
|
|
|
|
|
kfree(counter);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Read the performance counter - simple non blocking version for now
|
|
|
|
*/
|
|
|
|
static ssize_t
|
|
|
|
perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count)
|
|
|
|
{
|
|
|
|
u64 cntval;
|
|
|
|
|
|
|
|
if (count != sizeof(cntval))
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
mutex_lock(&counter->mutex);
|
2008-12-11 00:38:42 -07:00
|
|
|
cntval = perf_counter_read(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
mutex_unlock(&counter->mutex);
|
|
|
|
|
|
|
|
return put_user(cntval, (u64 __user *) buf) ? -EFAULT : sizeof(cntval);
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
perf_copy_usrdata(struct perf_data *usrdata, char __user *buf, size_t count)
|
|
|
|
{
|
|
|
|
if (!usrdata->len)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
count = min(count, (size_t)usrdata->len);
|
|
|
|
if (copy_to_user(buf, usrdata->data + usrdata->rd_idx, count))
|
|
|
|
return -EFAULT;
|
|
|
|
|
|
|
|
/* Adjust the counters */
|
|
|
|
usrdata->len -= count;
|
|
|
|
if (!usrdata->len)
|
|
|
|
usrdata->rd_idx = 0;
|
|
|
|
else
|
|
|
|
usrdata->rd_idx += count;
|
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
perf_read_irq_data(struct perf_counter *counter,
|
|
|
|
char __user *buf,
|
|
|
|
size_t count,
|
|
|
|
int nonblocking)
|
|
|
|
{
|
|
|
|
struct perf_data *irqdata, *usrdata;
|
|
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
ssize_t res;
|
|
|
|
|
|
|
|
irqdata = counter->irqdata;
|
|
|
|
usrdata = counter->usrdata;
|
|
|
|
|
|
|
|
if (usrdata->len + irqdata->len >= count)
|
|
|
|
goto read_pending;
|
|
|
|
|
|
|
|
if (nonblocking)
|
|
|
|
return -EAGAIN;
|
|
|
|
|
|
|
|
spin_lock_irq(&counter->waitq.lock);
|
|
|
|
__add_wait_queue(&counter->waitq, &wait);
|
|
|
|
for (;;) {
|
|
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
|
|
if (usrdata->len + irqdata->len >= count)
|
|
|
|
break;
|
|
|
|
|
|
|
|
if (signal_pending(current))
|
|
|
|
break;
|
|
|
|
|
|
|
|
spin_unlock_irq(&counter->waitq.lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_irq(&counter->waitq.lock);
|
|
|
|
}
|
|
|
|
__remove_wait_queue(&counter->waitq, &wait);
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
|
|
spin_unlock_irq(&counter->waitq.lock);
|
|
|
|
|
|
|
|
if (usrdata->len + irqdata->len < count)
|
|
|
|
return -ERESTARTSYS;
|
|
|
|
read_pending:
|
|
|
|
mutex_lock(&counter->mutex);
|
|
|
|
|
|
|
|
/* Drain pending data first: */
|
|
|
|
res = perf_copy_usrdata(usrdata, buf, count);
|
|
|
|
if (res < 0 || res == count)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
/* Switch irq buffer: */
|
|
|
|
usrdata = perf_switch_irq_data(counter);
|
|
|
|
if (perf_copy_usrdata(usrdata, buf + res, count - res) < 0) {
|
|
|
|
if (!res)
|
|
|
|
res = -EFAULT;
|
|
|
|
} else {
|
|
|
|
res = count;
|
|
|
|
}
|
|
|
|
out:
|
|
|
|
mutex_unlock(&counter->mutex);
|
|
|
|
|
|
|
|
return res;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
|
|
{
|
|
|
|
struct perf_counter *counter = file->private_data;
|
|
|
|
|
2008-12-10 04:33:23 -07:00
|
|
|
switch (counter->hw_event.record_type) {
|
2008-12-04 12:12:29 -07:00
|
|
|
case PERF_RECORD_SIMPLE:
|
|
|
|
return perf_read_hw(counter, buf, count);
|
|
|
|
|
|
|
|
case PERF_RECORD_IRQ:
|
|
|
|
case PERF_RECORD_GROUP:
|
|
|
|
return perf_read_irq_data(counter, buf, count,
|
|
|
|
file->f_flags & O_NONBLOCK);
|
|
|
|
}
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static unsigned int perf_poll(struct file *file, poll_table *wait)
|
|
|
|
{
|
|
|
|
struct perf_counter *counter = file->private_data;
|
|
|
|
unsigned int events = 0;
|
|
|
|
unsigned long flags;
|
|
|
|
|
|
|
|
poll_wait(file, &counter->waitq, wait);
|
|
|
|
|
|
|
|
spin_lock_irqsave(&counter->waitq.lock, flags);
|
|
|
|
if (counter->usrdata->len || counter->irqdata->len)
|
|
|
|
events |= POLLIN;
|
|
|
|
spin_unlock_irqrestore(&counter->waitq.lock, flags);
|
|
|
|
|
|
|
|
return events;
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct file_operations perf_fops = {
|
|
|
|
.release = perf_release,
|
|
|
|
.read = perf_read,
|
|
|
|
.poll = perf_poll,
|
|
|
|
};
|
|
|
|
|
2008-12-11 05:21:10 -07:00
|
|
|
static void cpu_clock_perf_counter_enable(struct perf_counter *counter)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
|
|
|
|
static void cpu_clock_perf_counter_disable(struct perf_counter *counter)
|
|
|
|
{
|
|
|
|
}
|
|
|
|
|
|
|
|
static void cpu_clock_perf_counter_read(struct perf_counter *counter)
|
|
|
|
{
|
|
|
|
int cpu = raw_smp_processor_id();
|
|
|
|
|
|
|
|
atomic64_counter_set(counter, cpu_clock(cpu));
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct hw_perf_counter_ops perf_ops_cpu_clock = {
|
|
|
|
.hw_perf_counter_enable = cpu_clock_perf_counter_enable,
|
|
|
|
.hw_perf_counter_disable = cpu_clock_perf_counter_disable,
|
|
|
|
.hw_perf_counter_read = cpu_clock_perf_counter_read,
|
|
|
|
};
|
|
|
|
|
|
|
|
static const struct hw_perf_counter_ops *
|
|
|
|
sw_perf_counter_init(struct perf_counter *counter)
|
|
|
|
{
|
|
|
|
const struct hw_perf_counter_ops *hw_ops = NULL;
|
|
|
|
|
|
|
|
switch (counter->hw_event.type) {
|
|
|
|
case PERF_COUNT_CPU_CLOCK:
|
|
|
|
hw_ops = &perf_ops_cpu_clock;
|
|
|
|
break;
|
|
|
|
default:
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
return hw_ops;
|
|
|
|
}
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
/*
|
|
|
|
* Allocate and initialize a counter structure
|
|
|
|
*/
|
|
|
|
static struct perf_counter *
|
2008-12-11 00:38:42 -07:00
|
|
|
perf_counter_alloc(struct perf_counter_hw_event *hw_event,
|
|
|
|
int cpu,
|
|
|
|
struct perf_counter *group_leader)
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
2008-12-11 05:21:10 -07:00
|
|
|
const struct hw_perf_counter_ops *hw_ops;
|
2008-12-11 04:46:46 -07:00
|
|
|
struct perf_counter *counter;
|
2008-12-04 12:12:29 -07:00
|
|
|
|
2008-12-11 04:46:46 -07:00
|
|
|
counter = kzalloc(sizeof(*counter), GFP_KERNEL);
|
2008-12-04 12:12:29 -07:00
|
|
|
if (!counter)
|
|
|
|
return NULL;
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
/*
|
|
|
|
* Single counters are their own group leaders, with an
|
|
|
|
* empty sibling list:
|
|
|
|
*/
|
|
|
|
if (!group_leader)
|
|
|
|
group_leader = counter;
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
mutex_init(&counter->mutex);
|
2008-12-11 00:38:42 -07:00
|
|
|
INIT_LIST_HEAD(&counter->list_entry);
|
|
|
|
INIT_LIST_HEAD(&counter->sibling_list);
|
2008-12-04 12:12:29 -07:00
|
|
|
init_waitqueue_head(&counter->waitq);
|
|
|
|
|
2008-12-10 04:33:23 -07:00
|
|
|
counter->irqdata = &counter->data[0];
|
|
|
|
counter->usrdata = &counter->data[1];
|
|
|
|
counter->cpu = cpu;
|
|
|
|
counter->hw_event = *hw_event;
|
|
|
|
counter->wakeup_pending = 0;
|
2008-12-11 00:38:42 -07:00
|
|
|
counter->group_leader = group_leader;
|
2008-12-11 04:46:46 -07:00
|
|
|
counter->hw_ops = NULL;
|
|
|
|
|
2008-12-11 05:21:10 -07:00
|
|
|
hw_ops = NULL;
|
|
|
|
if (!hw_event->raw && hw_event->type < 0)
|
|
|
|
hw_ops = sw_perf_counter_init(counter);
|
|
|
|
if (!hw_ops) {
|
|
|
|
hw_ops = hw_perf_counter_init(counter);
|
|
|
|
}
|
|
|
|
|
2008-12-11 04:46:46 -07:00
|
|
|
if (!hw_ops) {
|
|
|
|
kfree(counter);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
counter->hw_ops = hw_ops;
|
2008-12-04 12:12:29 -07:00
|
|
|
|
|
|
|
return counter;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2008-12-10 04:33:23 -07:00
|
|
|
* sys_perf_task_open - open a performance counter, associate it to a task/cpu
|
|
|
|
*
|
|
|
|
* @hw_event_uptr: event type attributes for monitoring/sampling
|
2008-12-04 12:12:29 -07:00
|
|
|
* @pid: target pid
|
2008-12-10 04:33:23 -07:00
|
|
|
* @cpu: target cpu
|
|
|
|
* @group_fd: group leader counter fd
|
2008-12-04 12:12:29 -07:00
|
|
|
*/
|
2008-12-10 04:33:23 -07:00
|
|
|
asmlinkage int sys_perf_counter_open(
|
|
|
|
|
|
|
|
struct perf_counter_hw_event *hw_event_uptr __user,
|
|
|
|
pid_t pid,
|
|
|
|
int cpu,
|
|
|
|
int group_fd)
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
2008-12-11 00:38:42 -07:00
|
|
|
struct perf_counter *counter, *group_leader;
|
2008-12-10 04:33:23 -07:00
|
|
|
struct perf_counter_hw_event hw_event;
|
2008-12-11 00:38:42 -07:00
|
|
|
struct perf_counter_context *ctx;
|
|
|
|
struct file *group_file = NULL;
|
|
|
|
int fput_needed = 0;
|
2008-12-04 12:12:29 -07:00
|
|
|
int ret;
|
|
|
|
|
2008-12-10 04:33:23 -07:00
|
|
|
if (copy_from_user(&hw_event, hw_event_uptr, sizeof(hw_event)) != 0)
|
2008-12-08 11:26:59 -07:00
|
|
|
return -EFAULT;
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
/*
|
2008-12-11 03:26:29 -07:00
|
|
|
* Get the target context (task or percpu):
|
|
|
|
*/
|
|
|
|
ctx = find_get_context(pid, cpu);
|
|
|
|
if (IS_ERR(ctx))
|
|
|
|
return PTR_ERR(ctx);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Look up the group leader (we will attach this counter to it):
|
2008-12-11 00:38:42 -07:00
|
|
|
*/
|
|
|
|
group_leader = NULL;
|
|
|
|
if (group_fd != -1) {
|
|
|
|
ret = -EINVAL;
|
|
|
|
group_file = fget_light(group_fd, &fput_needed);
|
|
|
|
if (!group_file)
|
2008-12-11 03:26:29 -07:00
|
|
|
goto err_put_context;
|
2008-12-11 00:38:42 -07:00
|
|
|
if (group_file->f_op != &perf_fops)
|
2008-12-11 03:26:29 -07:00
|
|
|
goto err_put_context;
|
2008-12-11 00:38:42 -07:00
|
|
|
|
|
|
|
group_leader = group_file->private_data;
|
|
|
|
/*
|
2008-12-11 03:26:29 -07:00
|
|
|
* Do not allow a recursive hierarchy (this new sibling
|
|
|
|
* becoming part of another group-sibling):
|
|
|
|
*/
|
|
|
|
if (group_leader->group_leader != group_leader)
|
|
|
|
goto err_put_context;
|
|
|
|
/*
|
|
|
|
* Do not allow to attach to a group in a different
|
|
|
|
* task or CPU context:
|
2008-12-11 00:38:42 -07:00
|
|
|
*/
|
2008-12-11 03:26:29 -07:00
|
|
|
if (group_leader->ctx != ctx)
|
|
|
|
goto err_put_context;
|
2008-12-11 00:38:42 -07:00
|
|
|
}
|
|
|
|
|
2008-12-11 05:21:10 -07:00
|
|
|
ret = -EINVAL;
|
2008-12-11 00:38:42 -07:00
|
|
|
counter = perf_counter_alloc(&hw_event, cpu, group_leader);
|
2008-12-04 12:12:29 -07:00
|
|
|
if (!counter)
|
|
|
|
goto err_put_context;
|
|
|
|
|
|
|
|
perf_install_in_context(ctx, counter, cpu);
|
|
|
|
|
|
|
|
ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
|
|
|
|
if (ret < 0)
|
|
|
|
goto err_remove_free_put_context;
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
out_fput:
|
|
|
|
fput_light(group_file, fput_needed);
|
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
return ret;
|
|
|
|
|
|
|
|
err_remove_free_put_context:
|
|
|
|
mutex_lock(&counter->mutex);
|
2008-12-11 00:38:42 -07:00
|
|
|
perf_counter_remove_from_context(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
mutex_unlock(&counter->mutex);
|
|
|
|
kfree(counter);
|
|
|
|
|
|
|
|
err_put_context:
|
|
|
|
put_context(ctx);
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
goto out_fput;
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
static void __cpuinit perf_counter_init_cpu(int cpu)
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
2008-12-11 00:38:42 -07:00
|
|
|
struct perf_cpu_context *cpuctx;
|
2008-12-04 12:12:29 -07:00
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
cpuctx = &per_cpu(perf_cpu_context, cpu);
|
|
|
|
__perf_counter_init_context(&cpuctx->ctx, NULL);
|
2008-12-04 12:12:29 -07:00
|
|
|
|
|
|
|
mutex_lock(&perf_resource_mutex);
|
2008-12-11 00:38:42 -07:00
|
|
|
cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu;
|
2008-12-04 12:12:29 -07:00
|
|
|
mutex_unlock(&perf_resource_mutex);
|
2008-12-11 00:38:42 -07:00
|
|
|
|
2008-12-04 12:12:29 -07:00
|
|
|
hw_perf_counter_setup();
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
2008-12-11 00:38:42 -07:00
|
|
|
static void __perf_counter_exit_cpu(void *info)
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
|
|
|
|
struct perf_counter_context *ctx = &cpuctx->ctx;
|
|
|
|
struct perf_counter *counter, *tmp;
|
|
|
|
|
2008-12-11 00:38:42 -07:00
|
|
|
list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry)
|
|
|
|
__perf_counter_remove_from_context(counter);
|
2008-12-04 12:12:29 -07:00
|
|
|
|
|
|
|
}
|
2008-12-11 00:38:42 -07:00
|
|
|
static void perf_counter_exit_cpu(int cpu)
|
2008-12-04 12:12:29 -07:00
|
|
|
{
|
2008-12-11 00:38:42 -07:00
|
|
|
smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1);
|
2008-12-04 12:12:29 -07:00
|
|
|
}
|
|
|
|
#else
|
2008-12-11 00:38:42 -07:00
|
|
|
static inline void perf_counter_exit_cpu(int cpu) { }
|
2008-12-04 12:12:29 -07:00
|
|
|
#endif
|
|
|
|
|
|
|
|
static int __cpuinit
|
|
|
|
perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
|
|
|
|
{
|
|
|
|
unsigned int cpu = (long)hcpu;
|
|
|
|
|
|
|
|
switch (action) {
|
|
|
|
|
|
|
|
case CPU_UP_PREPARE:
|
|
|
|
case CPU_UP_PREPARE_FROZEN:
|
2008-12-11 00:38:42 -07:00
|
|
|
perf_counter_init_cpu(cpu);
|
2008-12-04 12:12:29 -07:00
|
|
|
break;
|
|
|
|
|
|
|
|
case CPU_DOWN_PREPARE:
|
|
|
|
case CPU_DOWN_PREPARE_FROZEN:
|
2008-12-11 00:38:42 -07:00
|
|
|
perf_counter_exit_cpu(cpu);
|
2008-12-04 12:12:29 -07:00
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
return NOTIFY_OK;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct notifier_block __cpuinitdata perf_cpu_nb = {
|
|
|
|
.notifier_call = perf_cpu_notify,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init perf_counter_init(void)
|
|
|
|
{
|
|
|
|
perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
|
|
|
|
(void *)(long)smp_processor_id());
|
|
|
|
register_cpu_notifier(&perf_cpu_nb);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
early_initcall(perf_counter_init);
|
|
|
|
|
|
|
|
static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf)
|
|
|
|
{
|
|
|
|
return sprintf(buf, "%d\n", perf_reserved_percpu);
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
perf_set_reserve_percpu(struct sysdev_class *class,
|
|
|
|
const char *buf,
|
|
|
|
size_t count)
|
|
|
|
{
|
|
|
|
struct perf_cpu_context *cpuctx;
|
|
|
|
unsigned long val;
|
|
|
|
int err, cpu, mpt;
|
|
|
|
|
|
|
|
err = strict_strtoul(buf, 10, &val);
|
|
|
|
if (err)
|
|
|
|
return err;
|
|
|
|
if (val > perf_max_counters)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
mutex_lock(&perf_resource_mutex);
|
|
|
|
perf_reserved_percpu = val;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
|
|
cpuctx = &per_cpu(perf_cpu_context, cpu);
|
|
|
|
spin_lock_irq(&cpuctx->ctx.lock);
|
|
|
|
mpt = min(perf_max_counters - cpuctx->ctx.nr_counters,
|
|
|
|
perf_max_counters - perf_reserved_percpu);
|
|
|
|
cpuctx->max_pertask = mpt;
|
|
|
|
spin_unlock_irq(&cpuctx->ctx.lock);
|
|
|
|
}
|
|
|
|
mutex_unlock(&perf_resource_mutex);
|
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf)
|
|
|
|
{
|
|
|
|
return sprintf(buf, "%d\n", perf_overcommit);
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t
|
|
|
|
perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count)
|
|
|
|
{
|
|
|
|
unsigned long val;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
err = strict_strtoul(buf, 10, &val);
|
|
|
|
if (err)
|
|
|
|
return err;
|
|
|
|
if (val > 1)
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
mutex_lock(&perf_resource_mutex);
|
|
|
|
perf_overcommit = val;
|
|
|
|
mutex_unlock(&perf_resource_mutex);
|
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
|
|
|
static SYSDEV_CLASS_ATTR(
|
|
|
|
reserve_percpu,
|
|
|
|
0644,
|
|
|
|
perf_show_reserve_percpu,
|
|
|
|
perf_set_reserve_percpu
|
|
|
|
);
|
|
|
|
|
|
|
|
static SYSDEV_CLASS_ATTR(
|
|
|
|
overcommit,
|
|
|
|
0644,
|
|
|
|
perf_show_overcommit,
|
|
|
|
perf_set_overcommit
|
|
|
|
);
|
|
|
|
|
|
|
|
static struct attribute *perfclass_attrs[] = {
|
|
|
|
&attr_reserve_percpu.attr,
|
|
|
|
&attr_overcommit.attr,
|
|
|
|
NULL
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct attribute_group perfclass_attr_group = {
|
|
|
|
.attrs = perfclass_attrs,
|
|
|
|
.name = "perf_counters",
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init perf_counter_sysfs_init(void)
|
|
|
|
{
|
|
|
|
return sysfs_create_group(&cpu_sysdev_class.kset.kobj,
|
|
|
|
&perfclass_attr_group);
|
|
|
|
}
|
|
|
|
device_initcall(perf_counter_sysfs_init);
|
|
|
|
|