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  1. 05 12月, 2017 1 次提交
  3. 29 11月, 2017 1 次提交
  5. 17 11月, 2017 10 次提交
  7. 13 11月, 2017 13 次提交
  9. 26 10月, 2017 1 次提交
    • R
      perf symbols: Fix memory corruption because of zero length symbols · 331c7cb3
      由 Ravi Bangoria 提交于 
      Perf top is often crashing at very random locations on powerpc.  After
investigating, I found the crash only happens when sample is of zero
length symbol. Powerpc kernel has many such symbols which does not
contain length details in vmlinux binary and thus start and end
addresses of such symbols are same.

Structure

  struct sym_hist {
        u64                   nr_samples;
        u64                   period;
        struct sym_hist_entry addr[0];
  };

has last member 'addr[]' of size zero. 'addr[]' is an array of addresses
that belongs to one symbol (function). If function consist of 100
instructions, 'addr' points to an array of 100 'struct sym_hist_entry'
elements. For zero length symbol, it points to the *empty* array, i.e.
no members in the array and thus offset 0 is also invalid for such
array.

  static int __symbol__inc_addr_samples(...)
  {
        ...
        offset = addr - sym->start;
        h = annotation__histogram(notes, evidx);
        h->nr_samples++;
        h->addr[offset].nr_samples++;
        h->period += sample->period;
        h->addr[offset].period += sample->period;
        ...
  }

Here, when 'addr' is same as 'sym->start', 'offset' becomes 0, which is
valid for normal symbols but *invalid* for zero length symbols and thus
updating h->addr[offset] causes memory corruption.

Fix this by adding one dummy element for zero length symbols.

Link: https://lkml.org/lkml/2016/10/10/148
Fixes: edee44be ("perf annotate: Don't throw error for zero length symbols")
Signed-off-by: NRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: http://lkml.kernel.org/r/1508854806-10542-1-git-send-email-ravi.bangoria@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      331c7cb3
  11. 23 10月, 2017 1 次提交
  13. 18 8月, 2017 1 次提交
  15. 28 7月, 2017 1 次提交
  17. 27 7月, 2017 1 次提交
  19. 26 7月, 2017 1 次提交
  21. 25 7月, 2017 1 次提交
  23. 21 7月, 2017 4 次提交
  25. 19 7月, 2017 3 次提交
    • K
      perf buildid-cache: Cache debuginfo · d2396999
      由 Krister Johansen 提交于 
      If a stripped binary is placed in the cache, the user is in a situation
where there's a cached elf file present, but it doesn't have any symtab
to use for name resolution.  Grab the debuginfo for binaries that don't
end in .ko.  This yields a better chance of resolving symbols from older
traces.
Signed-off-by: NKrister Johansen <kjlx@templeofstupid.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1499305693-1599-7-git-send-email-kjlx@templeofstupid.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d2396999
    • J
      perf annotate: Implement visual marker for macro fusion · 7e63a13a
      由 Jin Yao 提交于 
      For marking fused instructions clearly this patch adds a line before the
first instruction of pair and joins it with the arrow of the jump to its
target.

For example, when "je" is selected in annotate view, the line before
cmpl is displayed and joins the arrow of "je".

       │   ┌──cmpl   $0x0,argp_program_version_hook
 81.93 │   ├──je     20
       │   │  lock   cmpxchg %esi,0x38a9a4(%rip)
       │   │↓ jne    29
       │   │↓ jmp    43
 11.47 │20:└─→cmpxch %esi,0x38a999(%rip)

That means the cmpl+je is a fused instruction pair and they should be
considered together.

Changelog:

v3: Use Arnaldo's fix to improve the arrow origin rendering.  To get the
    evsel->evlist->env->cpuid, save the evsel in annotate_browser.

v2: new function "ins__is_fused" to check if the instructions are fused.
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1499403995-19857-3-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      7e63a13a
    • J
      perf annotate: Check for fused instructions · 69fb09f6
      由 Jin Yao 提交于 
      Macro fusion merges two instructions to a single micro-op. Intel core
platform performs this hardware optimization under limited
circumstances.

For example, CMP + JCC can be "fused" and executed /retired together.
While with sampling this can result in the sample sometimes being on the
JCC and sometimes on the CMP.  So for the fused instruction pair, they
could be considered together.

On Nehalem, fused instruction pairs:

  cmp/test + jcc.

On other new CPU:

  cmp/test/add/sub/and/inc/dec + jcc.

This patch adds an x86-specific function which checks if 2 instructions
are in a "fused" pair. For non-x86 arch, the function is just NULL.

Changelog:

v4: Move the CPU model checking to symbol__disassemble and save the CPU
    family/model in arch structure.

    It avoids checking every time when jump arrow printed.

v3: Add checking for Nehalem (CMP, TEST). For other newer Intel CPUs
    just check it by default (CMP, TEST, ADD, SUB, AND, INC, DEC).

v2: Remove the original weak function. Arnaldo points out that doing it
    as a weak function that will be overridden by the host arch doesn't
    work. So now it's implemented as an arch-specific function.

Committer fix:

Do not access evsel->evlist->env->cpuid, ->env can be null, introduce
perf_evsel__env_cpuid(), just like perf_evsel__env_arch(), also used in
this function call.

The original patch was segfaulting 'perf top' + annotation.

But this essentially disables this fused instructions augmentation in
'perf top', the right thing is to get the cpuid from the running kernel,
left for a later patch tho.
Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1499403995-19857-2-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      69fb09f6
  27. 20 6月, 2017 1 次提交