ftrace: trace irq disabled critical timings
This patch adds latency tracing for critical timings
(how long interrupts are disabled for).
"irqsoff" is added to /debugfs/tracing/available_tracers
Note:
tracing_max_latency
also holds the max latency for irqsoff (in usecs).
(default to large number so one must start latency tracing)
tracing_thresh
threshold (in usecs) to always print out if irqs off
is detected to be longer than stated here.
If irq_thresh is non-zero, then max_irq_latency
is ignored.
Here's an example of a trace with ftrace_enabled = 0
=======
preemption latency trace v1.1.5 on 2.6.24-rc7
Signed-off-by: Ingo Molnar <mingo@elte.hu>
--------------------------------------------------------------------
latency: 100 us, #3/3, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2)
-----------------
| task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0)
-----------------
=> started at: _spin_lock_irqsave+0x2a/0xb7
=> ended at: _spin_unlock_irqrestore+0x32/0x5f
_------=> CPU#
/ _-----=> irqs-off
| / _----=> need-resched
|| / _---=> hardirq/softirq
||| / _--=> preempt-depth
|||| /
||||| delay
cmd pid ||||| time | caller
\ / ||||| \ | /
swapper-0 1d.s3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000])
swapper-0 1d.s3 100us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000])
swapper-0 1d.s3 100us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f)
vim:ft=help
=======
And this is a trace with ftrace_enabled == 1
=======
preemption latency trace v1.1.5 on 2.6.24-rc7
--------------------------------------------------------------------
latency: 102 us, #12/12, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2)
-----------------
| task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0)
-----------------
=> started at: _spin_lock_irqsave+0x2a/0xb7
=> ended at: _spin_unlock_irqrestore+0x32/0x5f
_------=> CPU#
/ _-----=> irqs-off
| / _----=> need-resched
|| / _---=> hardirq/softirq
||| / _--=> preempt-depth
|||| /
||||| delay
cmd pid ||||| time | caller
\ / ||||| \ | /
swapper-0 1dNs3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000])
swapper-0 1dNs3 46us : e1000_read_phy_reg+0x16/0x225 [e1000] (e1000_update_stats+0x5e2/0x64c [e1000])
swapper-0 1dNs3 46us : e1000_swfw_sync_acquire+0x10/0x99 [e1000] (e1000_read_phy_reg+0x49/0x225 [e1000])
swapper-0 1dNs3 46us : e1000_get_hw_eeprom_semaphore+0x12/0xa6 [e1000] (e1000_swfw_sync_acquire+0x36/0x99 [e1000])
swapper-0 1dNs3 47us : __const_udelay+0x9/0x47 (e1000_read_phy_reg+0x116/0x225 [e1000])
swapper-0 1dNs3 47us+: __delay+0x9/0x50 (__const_udelay+0x45/0x47)
swapper-0 1dNs3 97us : preempt_schedule+0xc/0x84 (__delay+0x4e/0x50)
swapper-0 1dNs3 98us : e1000_swfw_sync_release+0xc/0x55 [e1000] (e1000_read_phy_reg+0x211/0x225 [e1000])
swapper-0 1dNs3 99us+: e1000_put_hw_eeprom_semaphore+0x9/0x35 [e1000] (e1000_swfw_sync_release+0x50/0x55 [e1000])
swapper-0 1dNs3 101us : _spin_unlock_irqrestore+0xe/0x5f (e1000_update_stats+0x641/0x64c [e1000])
swapper-0 1dNs3 102us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000])
swapper-0 1dNs3 102us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f)
vim:ft=help
=======
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hifive-unleashed-5.1
Steven Rostedt
Thomas Gleixner
parent
352ad25aa4
commit
81d68a96a3
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@ -165,7 +165,10 @@ void cpu_idle(void)
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*/
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local_irq_disable();
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enter_idle();
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/* Don't trace irqs off for idle */
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stop_critical_timings();
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idle();
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start_critical_timings();
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/* In many cases the interrupt that ended idle
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has already called exit_idle. But some idle
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loops can be woken up without interrupt. */
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@ -5,6 +5,7 @@
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obj-$(CONFIG_SMP) := msr-on-cpu.o
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lib-y := delay_$(BITS).o
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lib-y += thunk_$(BITS).o
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lib-y += usercopy_$(BITS).o getuser_$(BITS).o putuser_$(BITS).o
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lib-y += memcpy_$(BITS).o
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@ -0,0 +1,47 @@
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/*
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* Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash)
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* Copyright 2008 by Steven Rostedt, Red Hat, Inc
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* (inspired by Andi Kleen's thunk_64.S)
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* Subject to the GNU public license, v.2. No warranty of any kind.
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*/
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#include <linux/linkage.h>
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#define ARCH_TRACE_IRQS_ON \
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pushl %eax; \
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pushl %ecx; \
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pushl %edx; \
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call trace_hardirqs_on; \
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popl %edx; \
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popl %ecx; \
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popl %eax;
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#define ARCH_TRACE_IRQS_OFF \
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pushl %eax; \
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pushl %ecx; \
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pushl %edx; \
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call trace_hardirqs_off; \
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popl %edx; \
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popl %ecx; \
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popl %eax;
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#ifdef CONFIG_TRACE_IRQFLAGS
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/* put return address in eax (arg1) */
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.macro thunk_ra name,func
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.globl \name
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\name:
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pushl %eax
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pushl %ecx
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pushl %edx
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/* Place EIP in the arg1 */
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movl 3*4(%esp), %eax
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call \func
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popl %edx
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popl %ecx
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popl %eax
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ret
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.endm
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thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller
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thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller
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#endif
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@ -2,6 +2,7 @@
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* Save registers before calling assembly functions. This avoids
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* disturbance of register allocation in some inline assembly constructs.
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* Copyright 2001,2002 by Andi Kleen, SuSE Labs.
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* Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc.
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* Subject to the GNU public license, v.2. No warranty of any kind.
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*/
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@ -42,8 +43,22 @@
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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thunk trace_hardirqs_on_thunk,trace_hardirqs_on
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thunk trace_hardirqs_off_thunk,trace_hardirqs_off
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/* put return address in rdi (arg1) */
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.macro thunk_ra name,func
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.globl \name
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\name:
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CFI_STARTPROC
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SAVE_ARGS
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/* SAVE_ARGS pushs 9 elements */
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/* the next element would be the rip */
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movq 9*8(%rsp), %rdi
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call \func
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jmp restore
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CFI_ENDPROC
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.endm
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thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller
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thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller
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#endif
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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@ -179,8 +179,6 @@ static inline void trace_hardirqs_fixup(void)
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* have a reliable stack. x86_64 only.
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*/
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#define SWAPGS_UNSAFE_STACK swapgs
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#define ARCH_TRACE_IRQS_ON call trace_hardirqs_on_thunk
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#define ARCH_TRACE_IRQS_OFF call trace_hardirqs_off_thunk
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#define ARCH_LOCKDEP_SYS_EXIT call lockdep_sys_exit_thunk
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#define ARCH_LOCKDEP_SYS_EXIT_IRQ \
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TRACE_IRQS_ON; \
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@ -192,24 +190,6 @@ static inline void trace_hardirqs_fixup(void)
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TRACE_IRQS_OFF;
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#else
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#define ARCH_TRACE_IRQS_ON \
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pushl %eax; \
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pushl %ecx; \
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pushl %edx; \
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call trace_hardirqs_on; \
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popl %edx; \
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popl %ecx; \
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popl %eax;
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#define ARCH_TRACE_IRQS_OFF \
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pushl %eax; \
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pushl %ecx; \
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pushl %edx; \
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call trace_hardirqs_off; \
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popl %edx; \
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popl %ecx; \
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popl %eax;
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#define ARCH_LOCKDEP_SYS_EXIT \
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pushl %eax; \
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pushl %ecx; \
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@ -223,8 +203,8 @@ static inline void trace_hardirqs_fixup(void)
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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# define TRACE_IRQS_ON ARCH_TRACE_IRQS_ON
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# define TRACE_IRQS_OFF ARCH_TRACE_IRQS_OFF
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# define TRACE_IRQS_ON call trace_hardirqs_on_thunk;
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# define TRACE_IRQS_OFF call trace_hardirqs_off_thunk;
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#else
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# define TRACE_IRQS_ON
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# define TRACE_IRQS_OFF
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@ -50,4 +50,12 @@ extern void mcount(void);
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# define CALLER_ADDR5 0UL
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#endif
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#ifdef CONFIG_IRQSOFF_TRACER
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extern void notrace time_hardirqs_on(unsigned long a0, unsigned long a1);
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extern void notrace time_hardirqs_off(unsigned long a0, unsigned long a1);
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#else
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# define time_hardirqs_on(a0, a1) do { } while (0)
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# define time_hardirqs_off(a0, a1) do { } while (0)
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#endif
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#endif /* _LINUX_FTRACE_H */
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@ -12,10 +12,10 @@
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#define _LINUX_TRACE_IRQFLAGS_H
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#ifdef CONFIG_TRACE_IRQFLAGS
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extern void trace_hardirqs_on(void);
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extern void trace_hardirqs_off(void);
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extern void trace_softirqs_on(unsigned long ip);
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extern void trace_softirqs_off(unsigned long ip);
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extern void trace_hardirqs_on(void);
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extern void trace_hardirqs_off(void);
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# define trace_hardirq_context(p) ((p)->hardirq_context)
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# define trace_softirq_context(p) ((p)->softirq_context)
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# define trace_hardirqs_enabled(p) ((p)->hardirqs_enabled)
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@ -41,6 +41,14 @@
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# define INIT_TRACE_IRQFLAGS
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#endif
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#ifdef CONFIG_IRQSOFF_TRACER
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extern void stop_critical_timings(void);
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extern void start_critical_timings(void);
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#else
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# define stop_critical_timings() do { } while (0)
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# define start_critical_timings() do { } while (0)
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
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#include <asm/irqflags.h>
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@ -909,7 +909,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
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rt_mutex_init_task(p);
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#ifdef CONFIG_TRACE_IRQFLAGS
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#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_LOCKDEP)
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DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
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DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
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#endif
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@ -39,6 +39,7 @@
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#include <linux/irqflags.h>
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#include <linux/utsname.h>
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#include <linux/hash.h>
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#include <linux/ftrace.h>
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#include <asm/sections.h>
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@ -982,7 +983,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
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return 1;
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}
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#ifdef CONFIG_TRACE_IRQFLAGS
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#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
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/*
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* Forwards and backwards subgraph searching, for the purposes of
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* proving that two subgraphs can be connected by a new dependency
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@ -1680,7 +1681,7 @@ valid_state(struct task_struct *curr, struct held_lock *this,
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static int mark_lock(struct task_struct *curr, struct held_lock *this,
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enum lock_usage_bit new_bit);
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#ifdef CONFIG_TRACE_IRQFLAGS
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#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
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/*
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* print irq inversion bug:
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@ -2013,11 +2014,13 @@ void early_boot_irqs_on(void)
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/*
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* Hardirqs will be enabled:
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*/
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void trace_hardirqs_on(void)
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void notrace trace_hardirqs_on_caller(unsigned long a0)
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{
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struct task_struct *curr = current;
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unsigned long ip;
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time_hardirqs_on(CALLER_ADDR0, a0);
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if (unlikely(!debug_locks || current->lockdep_recursion))
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return;
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@ -2055,16 +2058,23 @@ void trace_hardirqs_on(void)
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curr->hardirq_enable_event = ++curr->irq_events;
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debug_atomic_inc(&hardirqs_on_events);
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}
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EXPORT_SYMBOL(trace_hardirqs_on_caller);
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void notrace trace_hardirqs_on(void)
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{
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trace_hardirqs_on_caller(CALLER_ADDR0);
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}
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EXPORT_SYMBOL(trace_hardirqs_on);
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/*
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* Hardirqs were disabled:
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*/
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void trace_hardirqs_off(void)
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void notrace trace_hardirqs_off_caller(unsigned long a0)
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{
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struct task_struct *curr = current;
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time_hardirqs_off(CALLER_ADDR0, a0);
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if (unlikely(!debug_locks || current->lockdep_recursion))
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return;
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@ -2082,7 +2092,12 @@ void trace_hardirqs_off(void)
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} else
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debug_atomic_inc(&redundant_hardirqs_off);
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}
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EXPORT_SYMBOL(trace_hardirqs_off_caller);
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void notrace trace_hardirqs_off(void)
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{
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trace_hardirqs_off_caller(CALLER_ADDR0);
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}
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EXPORT_SYMBOL(trace_hardirqs_off);
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/*
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@ -1041,7 +1041,9 @@ void release_console_sem(void)
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_log_end = log_end;
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con_start = log_end; /* Flush */
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spin_unlock(&logbuf_lock);
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stop_critical_timings(); /* don't trace print latency */
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call_console_drivers(_con_start, _log_end);
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start_critical_timings();
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local_irq_restore(flags);
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}
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console_locked = 0;
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@ -26,6 +26,24 @@ config FTRACE
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(the bootup default), then the overhead of the instructions is very
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small and not measurable even in micro-benchmarks.
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config IRQSOFF_TRACER
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bool "Interrupts-off Latency Tracer"
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default n
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depends on TRACE_IRQFLAGS_SUPPORT
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depends on GENERIC_TIME
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select TRACE_IRQFLAGS
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select TRACING
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select TRACER_MAX_TRACE
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help
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This option measures the time spent in irqs-off critical
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sections, with microsecond accuracy.
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The default measurement method is a maximum search, which is
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disabled by default and can be runtime (re-)started
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via:
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echo 0 > /debugfs/tracing/tracing_max_latency
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config SCHED_TRACER
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bool "Scheduling Latency Tracer"
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depends on DEBUG_KERNEL
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@ -3,6 +3,7 @@ obj-$(CONFIG_FTRACE) += libftrace.o
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obj-$(CONFIG_TRACING) += trace.o
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obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
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obj-$(CONFIG_FTRACE) += trace_functions.o
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obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
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obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
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libftrace-y := ftrace.o
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@ -0,0 +1,402 @@
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/*
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* trace irqs off criticall timings
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* From code in the latency_tracer, that is:
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*
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 William Lee Irwin III
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*/
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#include <linux/kallsyms.h>
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <linux/ftrace.h>
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#include <linux/fs.h>
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#include "trace.h"
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static struct trace_array *irqsoff_trace __read_mostly;
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static int tracer_enabled __read_mostly;
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/*
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* Sequence count - we record it when starting a measurement and
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* skip the latency if the sequence has changed - some other section
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* did a maximum and could disturb our measurement with serial console
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* printouts, etc. Truly coinciding maximum latencies should be rare
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* and what happens together happens separately as well, so this doesnt
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* decrease the validity of the maximum found:
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*/
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static __cacheline_aligned_in_smp unsigned long max_sequence;
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#ifdef CONFIG_FTRACE
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/*
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* irqsoff uses its own tracer function to keep the overhead down:
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*/
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static void notrace
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irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
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{
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struct trace_array *tr = irqsoff_trace;
|
||||
struct trace_array_cpu *data;
|
||||
unsigned long flags;
|
||||
long disabled;
|
||||
int cpu;
|
||||
|
||||
if (likely(!tracer_enabled))
|
||||
return;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (!irqs_disabled_flags(flags))
|
||||
return;
|
||||
|
||||
cpu = raw_smp_processor_id();
|
||||
data = tr->data[cpu];
|
||||
disabled = atomic_inc_return(&data->disabled);
|
||||
|
||||
if (likely(disabled == 1))
|
||||
ftrace(tr, data, ip, parent_ip, flags);
|
||||
|
||||
atomic_dec(&data->disabled);
|
||||
}
|
||||
|
||||
static struct ftrace_ops trace_ops __read_mostly =
|
||||
{
|
||||
.func = irqsoff_tracer_call,
|
||||
};
|
||||
#endif /* CONFIG_FTRACE */
|
||||
|
||||
/*
|
||||
* Should this new latency be reported/recorded?
|
||||
*/
|
||||
static int notrace report_latency(cycle_t delta)
|
||||
{
|
||||
if (tracing_thresh) {
|
||||
if (delta < tracing_thresh)
|
||||
return 0;
|
||||
} else {
|
||||
if (delta <= tracing_max_latency)
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void notrace
|
||||
check_critical_timing(struct trace_array *tr,
|
||||
struct trace_array_cpu *data,
|
||||
unsigned long parent_ip,
|
||||
int cpu)
|
||||
{
|
||||
unsigned long latency, t0, t1;
|
||||
cycle_t T0, T1, T2, delta;
|
||||
unsigned long flags;
|
||||
|
||||
/*
|
||||
* usecs conversion is slow so we try to delay the conversion
|
||||
* as long as possible:
|
||||
*/
|
||||
T0 = data->preempt_timestamp;
|
||||
T1 = now(cpu);
|
||||
delta = T1-T0;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (!report_latency(delta))
|
||||
goto out;
|
||||
|
||||
ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
|
||||
/*
|
||||
* Update the timestamp, because the trace entry above
|
||||
* might change it (it can only get larger so the latency
|
||||
* is fair to be reported):
|
||||
*/
|
||||
T2 = now(cpu);
|
||||
|
||||
delta = T2-T0;
|
||||
|
||||
latency = nsecs_to_usecs(delta);
|
||||
|
||||
if (data->critical_sequence != max_sequence)
|
||||
goto out;
|
||||
|
||||
tracing_max_latency = delta;
|
||||
t0 = nsecs_to_usecs(T0);
|
||||
t1 = nsecs_to_usecs(T1);
|
||||
|
||||
data->critical_end = parent_ip;
|
||||
|
||||
update_max_tr_single(tr, current, cpu);
|
||||
|
||||
if (tracing_thresh)
|
||||
printk(KERN_INFO "(%16s-%-5d|#%d): %lu us critical section "
|
||||
"violates %lu us threshold.\n"
|
||||
" => started at timestamp %lu: ",
|
||||
current->comm, current->pid,
|
||||
raw_smp_processor_id(),
|
||||
latency, nsecs_to_usecs(tracing_thresh), t0);
|
||||
else
|
||||
printk(KERN_INFO "(%16s-%-5d|#%d):"
|
||||
" new %lu us maximum-latency "
|
||||
"critical section.\n => started at timestamp %lu: ",
|
||||
current->comm, current->pid,
|
||||
raw_smp_processor_id(),
|
||||
latency, t0);
|
||||
|
||||
print_symbol(KERN_CONT "<%s>\n", data->critical_start);
|
||||
printk(KERN_CONT " => ended at timestamp %lu: ", t1);
|
||||
print_symbol(KERN_CONT "<%s>\n", data->critical_end);
|
||||
dump_stack();
|
||||
t1 = nsecs_to_usecs(now(cpu));
|
||||
printk(KERN_CONT " => dump-end timestamp %lu\n\n", t1);
|
||||
|
||||
max_sequence++;
|
||||
|
||||
out:
|
||||
data->critical_sequence = max_sequence;
|
||||
data->preempt_timestamp = now(cpu);
|
||||
tracing_reset(data);
|
||||
ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
|
||||
}
|
||||
|
||||
static inline void notrace
|
||||
start_critical_timing(unsigned long ip, unsigned long parent_ip)
|
||||
{
|
||||
int cpu;
|
||||
struct trace_array *tr = irqsoff_trace;
|
||||
struct trace_array_cpu *data;
|
||||
unsigned long flags;
|
||||
|
||||
if (likely(!tracer_enabled))
|
||||
return;
|
||||
|
||||
cpu = raw_smp_processor_id();
|
||||
data = tr->data[cpu];
|
||||
|
||||
if (unlikely(!data) || unlikely(!data->trace) ||
|
||||
data->critical_start || atomic_read(&data->disabled))
|
||||
return;
|
||||
|
||||
atomic_inc(&data->disabled);
|
||||
|
||||
data->critical_sequence = max_sequence;
|
||||
data->preempt_timestamp = now(cpu);
|
||||
data->critical_start = parent_ip;
|
||||
tracing_reset(data);
|
||||
|
||||
local_save_flags(flags);
|
||||
ftrace(tr, data, ip, parent_ip, flags);
|
||||
|
||||
atomic_dec(&data->disabled);
|
||||
}
|
||||
|
||||
static inline void notrace
|
||||
stop_critical_timing(unsigned long ip, unsigned long parent_ip)
|
||||
{
|
||||
int cpu;
|
||||
struct trace_array *tr = irqsoff_trace;
|
||||
struct trace_array_cpu *data;
|
||||
unsigned long flags;
|
||||
|
||||
if (likely(!tracer_enabled))
|
||||
return;
|
||||
|
||||
cpu = raw_smp_processor_id();
|
||||
data = tr->data[cpu];
|
||||
|
||||
if (unlikely(!data) || unlikely(!data->trace) ||
|
||||
!data->critical_start || atomic_read(&data->disabled))
|
||||
return;
|
||||
|
||||
atomic_inc(&data->disabled);
|
||||
local_save_flags(flags);
|
||||
ftrace(tr, data, ip, parent_ip, flags);
|
||||
check_critical_timing(tr, data, parent_ip, cpu);
|
||||
data->critical_start = 0;
|
||||
atomic_dec(&data->disabled);
|
||||
}
|
||||
|
||||
void notrace start_critical_timings(void)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
|
||||
}
|
||||
|
||||
void notrace stop_critical_timings(void)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_PROVE_LOCKING
|
||||
void notrace time_hardirqs_on(unsigned long a0, unsigned long a1)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
stop_critical_timing(a0, a1);
|
||||
}
|
||||
|
||||
void notrace time_hardirqs_off(unsigned long a0, unsigned long a1)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
start_critical_timing(a0, a1);
|
||||
}
|
||||
|
||||
#else /* !CONFIG_PROVE_LOCKING */
|
||||
|
||||
/*
|
||||
* Stubs:
|
||||
*/
|
||||
|
||||
void early_boot_irqs_off(void)
|
||||
{
|
||||
}
|
||||
|
||||
void early_boot_irqs_on(void)
|
||||
{
|
||||
}
|
||||
|
||||
void trace_softirqs_on(unsigned long ip)
|
||||
{
|
||||
}
|
||||
|
||||
void trace_softirqs_off(unsigned long ip)
|
||||
{
|
||||
}
|
||||
|
||||
inline void print_irqtrace_events(struct task_struct *curr)
|
||||
{
|
||||
}
|
||||
|
||||
/*
|
||||
* We are only interested in hardirq on/off events:
|
||||
*/
|
||||
void notrace trace_hardirqs_on(void)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
|
||||
}
|
||||
EXPORT_SYMBOL(trace_hardirqs_on);
|
||||
|
||||
void notrace trace_hardirqs_off(void)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
|
||||
}
|
||||
EXPORT_SYMBOL(trace_hardirqs_off);
|
||||
|
||||
void notrace trace_hardirqs_on_caller(unsigned long caller_addr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
stop_critical_timing(CALLER_ADDR0, caller_addr);
|
||||
}
|
||||
EXPORT_SYMBOL(trace_hardirqs_on_caller);
|
||||
|
||||
void notrace trace_hardirqs_off_caller(unsigned long caller_addr)
|
||||
{
|
||||
unsigned long flags;
|
||||
|
||||
local_save_flags(flags);
|
||||
|
||||
if (irqs_disabled_flags(flags))
|
||||
start_critical_timing(CALLER_ADDR0, caller_addr);
|
||||
}
|
||||
EXPORT_SYMBOL(trace_hardirqs_off_caller);
|
||||
|
||||
#endif /* CONFIG_PROVE_LOCKING */
|
||||
|
||||
static void start_irqsoff_tracer(struct trace_array *tr)
|
||||
{
|
||||
tracer_enabled = 1;
|
||||
register_ftrace_function(&trace_ops);
|
||||
}
|
||||
|
||||
static void stop_irqsoff_tracer(struct trace_array *tr)
|
||||
{
|
||||
unregister_ftrace_function(&trace_ops);
|
||||
tracer_enabled = 0;
|
||||
}
|
||||
|
||||
static void irqsoff_tracer_init(struct trace_array *tr)
|
||||
{
|
||||
irqsoff_trace = tr;
|
||||
/* make sure that the tracer is visibel */
|
||||
smp_wmb();
|
||||
|
||||
if (tr->ctrl)
|
||||
start_irqsoff_tracer(tr);
|
||||
}
|
||||
|
||||
static void irqsoff_tracer_reset(struct trace_array *tr)
|
||||
{
|
||||
if (tr->ctrl)
|
||||
stop_irqsoff_tracer(tr);
|
||||
}
|
||||
|
||||
static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
|
||||
{
|
||||
if (tr->ctrl)
|
||||
start_irqsoff_tracer(tr);
|
||||
else
|
||||
stop_irqsoff_tracer(tr);
|
||||
}
|
||||
|
||||
static void notrace irqsoff_tracer_open(struct trace_iterator *iter)
|
||||
{
|
||||
/* stop the trace while dumping */
|
||||
if (iter->tr->ctrl)
|
||||
stop_irqsoff_tracer(iter->tr);
|
||||
}
|
||||
|
||||
static void notrace irqsoff_tracer_close(struct trace_iterator *iter)
|
||||
{
|
||||
if (iter->tr->ctrl)
|
||||
start_irqsoff_tracer(iter->tr);
|
||||
}
|
||||
|
||||
static struct tracer irqsoff_tracer __read_mostly =
|
||||
{
|
||||
.name = "irqsoff",
|
||||
.init = irqsoff_tracer_init,
|
||||
.reset = irqsoff_tracer_reset,
|
||||
.open = irqsoff_tracer_open,
|
||||
.close = irqsoff_tracer_close,
|
||||
.ctrl_update = irqsoff_tracer_ctrl_update,
|
||||
.print_max = 1,
|
||||
};
|
||||
|
||||
__init static int init_irqsoff_tracer(void)
|
||||
{
|
||||
register_tracer(&irqsoff_tracer);
|
||||
|
||||
return 0;
|
||||
}
|
||||
device_initcall(init_irqsoff_tracer);
|
||||
Loading…
Reference in New Issue