kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

perf/x86: Enable free running PEBS for REGS_USER/INTR

Browse source 
Currently free running PEBS is disabled when user or interrupt
registers are requested. Most of the registers are actually
available in the PEBS record and can be supported.

So we just need to check for the supported registers and then
allow it: it is all except for the segment register.

For user registers this only works when the counter is limited
to ring 3 only, so this also needs to be checked.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170831214630.21892-1-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andi Kleen 2017-08-31 14:46:30 -07:00 committed by Ingo Molnar
parent 5bce9db189
commit a47ba4d77e
2 changed files with 27 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
arch/x86/events/intel/core.c
View file

@ -2958,6 +2958,10 @@ static unsigned long intel_pmu_free_running_flags(struct perf_event *event)
if (event->attr.use_clockid)
flags &= ~PERF_SAMPLE_TIME;
if (!event->attr.exclude_kernel)
flags &= ~PERF_SAMPLE_REGS_USER;
if (event->attr.sample_regs_user & ~PEBS_REGS)
flags &= ~(PERF_SAMPLE_REGS_USER | PERF_SAMPLE_REGS_INTR);
return flags;
}

24
arch/x86/events/perf_event.h
View file

@ -85,13 +85,15 @@ struct amd_nb {
* Flags PEBS can handle without an PMI.
*
* TID can only be handled by flushing at context switch.
* REGS_USER can be handled for events limited to ring 3.
*
*/
#define PEBS_FREERUNNING_FLAGS \
(PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_ADDR | \
PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \
PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR)
PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR | \
PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER)
/*
* A debug store configuration.
@ -110,6 +112,26 @@ struct debug_store {
u64 pebs_event_reset[MAX_PEBS_EVENTS];
};
#define PEBS_REGS \
(PERF_REG_X86_AX | \
PERF_REG_X86_BX | \
PERF_REG_X86_CX | \
PERF_REG_X86_DX | \
PERF_REG_X86_DI | \
PERF_REG_X86_SI | \
PERF_REG_X86_SP | \
PERF_REG_X86_BP | \
PERF_REG_X86_IP | \
PERF_REG_X86_FLAGS | \
PERF_REG_X86_R8 | \
PERF_REG_X86_R9 | \
PERF_REG_X86_R10 | \
PERF_REG_X86_R11 | \
PERF_REG_X86_R12 | \
PERF_REG_X86_R13 | \
PERF_REG_X86_R14 | \
PERF_REG_X86_R15)
/*
* Per register state.
*/