Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-26 22:21:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

perf/x86/intel: Record branch type

Browse Source 
Perf already has support for disassembling the branch instruction
and using the branch type for filtering. The patch just records
the branch type in perf_branch_entry.

Before recording, the patch converts the x86 branch type to
common branch type.

Change log:

v10: Set the branch_map array to be static. The previous version
     has it on stack then makes the compiler to create it every
     time when the function gets called.

v9: Use __ffs() to find first bit in type in common_branch_type().
    It lets the code be clear.

v8: Change PERF_BR_NONE to PERF_BR_UNKNOWN.

v7: Just convert following x86 branch types to common branch types.

X86_BR_CALL      -> PERF_BR_CALL
X86_BR_RET       -> PERF_BR_RET
X86_BR_JCC       -> PERF_BR_COND
X86_BR_JMP       -> PERF_BR_UNCOND
X86_BR_IND_CALL  -> PERF_BR_IND_CALL
X86_BR_ZERO_CALL -> PERF_BR_CALL
X86_BR_IND_JMP   -> PERF_BR_IND
X86_BR_SYSCALL   -> PERF_BR_SYSCALL
X86_BR_SYSRET    -> PERF_BR_SYSRET

Others are set to PERF_BR_NONE

v6: Not changed.

v5: Just fix the merge error. No other update.

v4: Comparing to previous version, the major changes are:

1. Uses a lookup table to convert x86 branch type to common branch
   type.

2. Move the JCC forward/JCC backward and cross page computing to
   user space.

3. Initialize branch type to 0 in intel_pmu_lbr_read_32 and
   intel_pmu_lbr_read_64

Signed-off-by: Yao Jin <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: http://lkml.kernel.org/r/1500379995-6449-3-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jin Yao 2017-07-18 20:13:10 +08:00 committed by Arnaldo Carvalho de Melo
parent eb0baf8a0d
commit d5c7f9dc58
1 changed files with 51 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
arch/x86/events/intel/lbr.c
View File

@ -109,6 +109,9 @@ enum {
X86_BR_ZERO_CALL = 1 << 15,/* zero length call */
X86_BR_CALL_STACK = 1 << 16,/* call stack */
X86_BR_IND_JMP = 1 << 17,/* indirect jump */
X86_BR_TYPE_SAVE = 1 << 18,/* indicate to save branch type */
};
#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL)
@ -510,6 +513,7 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
cpuc->lbr_entries[i].in_tx = 0;
cpuc->lbr_entries[i].abort = 0;
cpuc->lbr_entries[i].cycles = 0;
cpuc->lbr_entries[i].type = 0;
cpuc->lbr_entries[i].reserved = 0;
}
cpuc->lbr_stack.nr = i;
@ -596,6 +600,7 @@ static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
cpuc->lbr_entries[out].in_tx = in_tx;
cpuc->lbr_entries[out].abort = abort;
cpuc->lbr_entries[out].cycles = cycles;
cpuc->lbr_entries[out].type = 0;
cpuc->lbr_entries[out].reserved = 0;
out++;
}
@ -673,6 +678,10 @@ static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
if (br_type & PERF_SAMPLE_BRANCH_CALL)
mask |= X86_BR_CALL | X86_BR_ZERO_CALL;
if (br_type & PERF_SAMPLE_BRANCH_TYPE_SAVE)
mask |= X86_BR_TYPE_SAVE;
/*
* stash actual user request into reg, it may
* be used by fixup code for some CPU
@ -926,6 +935,43 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
return ret;
}
#define X86_BR_TYPE_MAP_MAX 16
static int branch_map[X86_BR_TYPE_MAP_MAX] = {
PERF_BR_CALL, /* X86_BR_CALL */
PERF_BR_RET, /* X86_BR_RET */
PERF_BR_SYSCALL, /* X86_BR_SYSCALL */
PERF_BR_SYSRET, /* X86_BR_SYSRET */
PERF_BR_UNKNOWN, /* X86_BR_INT */
PERF_BR_UNKNOWN, /* X86_BR_IRET */
PERF_BR_COND, /* X86_BR_JCC */
PERF_BR_UNCOND, /* X86_BR_JMP */
PERF_BR_UNKNOWN, /* X86_BR_IRQ */
PERF_BR_IND_CALL, /* X86_BR_IND_CALL */
PERF_BR_UNKNOWN, /* X86_BR_ABORT */
PERF_BR_UNKNOWN, /* X86_BR_IN_TX */
PERF_BR_UNKNOWN, /* X86_BR_NO_TX */
PERF_BR_CALL, /* X86_BR_ZERO_CALL */
PERF_BR_UNKNOWN, /* X86_BR_CALL_STACK */
PERF_BR_IND, /* X86_BR_IND_JMP */
};
static int
common_branch_type(int type)
{
int i;
type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */
if (type) {
i = __ffs(type);
if (i < X86_BR_TYPE_MAP_MAX)
return branch_map[i];
}
return PERF_BR_UNKNOWN;
}
/*
* implement actual branch filter based on user demand.
* Hardware may not exactly satisfy that request, thus
@ -942,7 +988,8 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
bool compress = false;
/* if sampling all branches, then nothing to filter */
if ((br_sel & X86_BR_ALL) == X86_BR_ALL)
if (((br_sel & X86_BR_ALL) == X86_BR_ALL) &&
((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE))
return;
for (i = 0; i < cpuc->lbr_stack.nr; i++) {
@ -963,6 +1010,9 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
cpuc->lbr_entries[i].from = 0;
compress = true;
}
if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE)
cpuc->lbr_entries[i].type = common_branch_type(type);
}
if (!compress)