<feed xmlns='http://www.w3.org/2005/Atom'>
<title>talos-obmc-linux/tools/perf, branch dev-4.13</title>
<subtitle>Talos™ II Linux sources for OpenBMC</subtitle>
<id>https://git.raptorcs.com/git/talos-obmc-linux/atom?h=dev-4.13</id>
<link rel='self' href='https://git.raptorcs.com/git/talos-obmc-linux/atom?h=dev-4.13'/>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/'/>
<updated>2017-10-21T15:55:06+00:00</updated>
<entry>
<title>perf pmu: Unbreak perf record for arm/arm64 with events with explicit PMU</title>
<updated>2017-10-21T15:55:06+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2017-10-06T18:38:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=74b6b98867585d00ff469432847f99766a0edd74'/>
<id>urn:sha1:74b6b98867585d00ff469432847f99766a0edd74</id>
<content type='text'>
commit 66ec11919a0f96e936bb731fdbc2851316077d26 upstream.

Currently, perf record is broken on arm/arm64 systems when the PMU is
specified explicitly as part of the event, e.g.

$ ./perf record -e armv8_cortex_a53/cpu_cycles/u true

In such cases, perf record fails to open events unless
perf_event_paranoid is set to -1, even if the PMU in question supports
mode exclusion. Further, even when perf_event_paranoid is toggled, no
samples are recorded.

This is an unintended side effect of commit:

  e3ba76deef23064f ("perf tools: Force uncore events to system wide monitoring)

... which assumes that if a PMU has an associated cpu_map, it is an
uncore PMU, and forces events for such PMUs to be system-wide.

This is not true for arm/arm64 systems, which can have heterogeneous
CPUs. To account for this, multiple CPU PMUs are exposed, each with a
"cpus" field under sysfs, which the perf tool parses into a cpu_map. ARM
PMUs do not have a "cpumask" file, and only have a "cpus" file. For the
gory details as to why, see commit:

 7e3fcffe95544010 ("perf pmu: Support alternative sysfs cpumask")

Given all of this, we can instead identify uncore PMUs by explicitly
checking for a "cpumask" file, and restore arm/arm64 PMU support back to
a working state. This patch does so, adding a new perf_pmu::is_uncore
field, and splitting the existing cpumask parsing so that it can be
reused.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Tested-by Will Deacon &lt;will.deacon@arm.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Fixes: e3ba76deef23064f ("perf tools: Force uncore events to system wide monitoring)
Link: http://lkml.kernel.org/r/1507315102-5942-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>perf script: Add missing separator for "-F ip,brstack" (and brstackoff)</title>
<updated>2017-10-18T07:38:31+00:00</updated>
<author>
<name>Mark Santaniello</name>
<email>marksan@fb.com</email>
</author>
<published>2017-10-06T08:07:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=5c5538c12db3b2e6023af83a17d6d1de4e994d08'/>
<id>urn:sha1:5c5538c12db3b2e6023af83a17d6d1de4e994d08</id>
<content type='text'>
commit e9516c0813aeb89ebd19ec0ed39fbfcd78b6ef3a upstream.

Prior to commit 55b9b50811ca ("perf script: Support -F brstack,dso and
brstacksym,dso"), we were printing a space before the brstack data. It
seems that this space was important.  Without it, parsing is difficult.

Very sorry for the mistake.

Notice here how the "ip" and "brstack" run together:

$ perf script -F ip,brstack | head -n 1
          22e18c40x22e19e2/0x22e190b/P/-/-/0 0x22e19a1/0x22e19d0/P/-/-/0 0x22e195d/0x22e1990/P/-/-/0 0x22e18e9/0x22e1943/P/-/-/0 0x22e1a69/0x22e18c0/P/-/-/0 0x22e19f7/0x22e1a20/P/-/-/0 0x22e1910/0x22e19ee/P/-/-/0 0x22e19e2/0x22e190b/P/-/-/0 0x22e19a1/0x22e19d0/P/-/-/0 0x22e195d/0x22e1990/P/-/-/0 0x22e18e9/0x22e1943/P/-/-/0 0x22e1a69/0x22e18c0/P/-/-/0 0x22e19f7/0x22e1a20/P/-/-/0 0x22e1910/0x22e19ee/P/-/-/0 0x22e19e2/0x22e190b/P/-/-/0 0x22e19a1/0x22e19d0/P/-/-/0

After this diff, sanity is restored:

$ perf script -F ip,brstack | head -n 1
          22e18c4 0x22e19e2/0x22e190b/P/-/-/0  0x22e19a1/0x22e19d0/P/-/-/0  0x22e195d/0x22e1990/P/-/-/0  0x22e18e9/0x22e1943/P/-/-/0  0x22e1a69/0x22e18c0/P/-/-/0  0x22e19f7/0x22e1a20/P/-/-/0  0x22e1910/0x22e19ee/P/-/-/0  0x22e19e2/0x22e190b/P/-/-/0  0x22e19a1/0x22e19d0/P/-/-/0  0x22e195d/0x22e1990/P/-/-/0  0x22e18e9/0x22e1943/P/-/-/0  0x22e1a69/0x22e18c0/P/-/-/0  0x22e19f7/0x22e1a20/P/-/-/0  0x22e1910/0x22e19ee/P/-/-/0  0x22e19e2/0x22e190b/P/-/-/0  0x22e19a1/0x22e19d0/P/-/-/0

Signed-off-by: Mark Santaniello &lt;marksan@fb.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Fixes: 55b9b50811ca ("perf script: Support -F brstack,dso and brstacksym,dso")
Link: http://lkml.kernel.org/r/20171006080722.3442046-1-marksan@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2017-07-21T18:12:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-07-21T18:12:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=bbcdea658f42070d25e7764f1b81785a51cb1642'/>
<id>urn:sha1:bbcdea658f42070d25e7764f1b81785a51cb1642</id>
<content type='text'>
Pull perf fixes from Ingo Molnar:
 "Two hw-enablement patches, two race fixes, three fixes for regressions
  of semantics, plus a number of tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Add proper condition to run sched_task callbacks
  perf/core: Fix locking for children siblings group read
  perf/core: Fix scheduling regression of pinned groups
  perf/x86/intel: Fix debug_store reset field for freq events
  perf/x86/intel: Add Goldmont Plus CPU PMU support
  perf/x86/intel: Enable C-state residency events for Apollo Lake
  perf symbols: Accept zero as the kernel base address
  Revert "perf/core: Drop kernel samples even though :u is specified"
  perf annotate: Fix broken arrow at row 0 connecting jmp instruction to its target
  perf evsel: State in the default event name if attr.exclude_kernel is set
  perf evsel: Fix attr.exclude_kernel setting for default cycles:p
</content>
</entry>
<entry>
<title>mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic</title>
<updated>2017-07-12T23:26:03+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2017-07-12T21:36:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=dcda9b04713c3f6ff0875652924844fae28286ea'/>
<id>urn:sha1:dcda9b04713c3f6ff0875652924844fae28286ea</id>
<content type='text'>
__GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to
the page allocator.  This has been true but only for allocations
requests larger than PAGE_ALLOC_COSTLY_ORDER.  It has been always
ignored for smaller sizes.  This is a bit unfortunate because there is
no way to express the same semantic for those requests and they are
considered too important to fail so they might end up looping in the
page allocator for ever, similarly to GFP_NOFAIL requests.

Now that the whole tree has been cleaned up and accidental or misled
usage of __GFP_REPEAT flag has been removed for !costly requests we can
give the original flag a better name and more importantly a more useful
semantic.  Let's rename it to __GFP_RETRY_MAYFAIL which tells the user
that the allocator would try really hard but there is no promise of a
success.  This will work independent of the order and overrides the
default allocator behavior.  Page allocator users have several levels of
guarantee vs.  cost options (take GFP_KERNEL as an example)

 - GFP_KERNEL &amp; ~__GFP_RECLAIM - optimistic allocation without _any_
   attempt to free memory at all. The most light weight mode which even
   doesn't kick the background reclaim. Should be used carefully because
   it might deplete the memory and the next user might hit the more
   aggressive reclaim

 - GFP_KERNEL &amp; ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic
   allocation without any attempt to free memory from the current
   context but can wake kswapd to reclaim memory if the zone is below
   the low watermark. Can be used from either atomic contexts or when
   the request is a performance optimization and there is another
   fallback for a slow path.

 - (GFP_KERNEL|__GFP_HIGH) &amp; ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) -
   non sleeping allocation with an expensive fallback so it can access
   some portion of memory reserves. Usually used from interrupt/bh
   context with an expensive slow path fallback.

 - GFP_KERNEL - both background and direct reclaim are allowed and the
   _default_ page allocator behavior is used. That means that !costly
   allocation requests are basically nofail but there is no guarantee of
   that behavior so failures have to be checked properly by callers
   (e.g. OOM killer victim is allowed to fail currently).

 - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior
   and all allocation requests fail early rather than cause disruptive
   reclaim (one round of reclaim in this implementation). The OOM killer
   is not invoked.

 - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator
   behavior and all allocation requests try really hard. The request
   will fail if the reclaim cannot make any progress. The OOM killer
   won't be triggered.

 - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior
   and all allocation requests will loop endlessly until they succeed.
   This might be really dangerous especially for larger orders.

Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL
because they already had their semantic.  No new users are added.
__alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if
there is no progress and we have already passed the OOM point.

This means that all the reclaim opportunities have been exhausted except
the most disruptive one (the OOM killer) and a user defined fallback
behavior is more sensible than keep retrying in the page allocator.

[akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c]
[mhocko@suse.com: semantic fix]
  Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz
[mhocko@kernel.org: address other thing spotted by Vlastimil]
  Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Alex Belits &lt;alex.belits@cavium.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Cc: David Daney &lt;david.daney@cavium.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Mel Gorman &lt;mgorman@suse.de&gt;
Cc: NeilBrown &lt;neilb@suse.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>perf symbols: Accept zero as the kernel base address</title>
<updated>2017-07-12T14:47:05+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2017-07-11T19:21:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=4b1303d0b01440f224cf81493b7e8e43d9b4965e'/>
<id>urn:sha1:4b1303d0b01440f224cf81493b7e8e43d9b4965e</id>
<content type='text'>
Which is the case in S/390, where symbols were not being resolved
because machine__get_kernel_start was only setting machine-&gt;kernel_start
when the just successfully loaded kernel symtab had its map-&gt;start set
to !0, when it was left at (1ULL &lt;&lt; 63) assuming a partitioning of the
address space for user/kernel, which is not the case in S/390 nor in
Sparc.

So just check if map__load() was successfull and set
machine-&gt;kernel_start to zero, fixing kernel symbol resolution on S/390.

Test performed by Thomas:

 ----

  I like this patch. I have done a new build and removed all my debug output to start
  from scratch. Without your patch I get this:

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object     Symbol
  # ........  ........  .......  ................  ........................
      75.00%     0.00%  true     [unknown]         [k] 0x00000000004bedda
              |
              ---0x4bedda
                 |
                 |--50.00%--0x42693a
                 |          |
                 |           --25.00%--0x2a72e0
                 |                     0x2af0ca
                 |                     0x3d1003fe4c0
                 |
                  --25.00%--0x4272bc
                            0x26fa84

  and with your patch (I just rebuilt the perf tool, nothing else and used the same
  perf.data file as input):

  # Samples: 4  of event 'cpu-clock'
  # Event count (approx.): 1000000
  #
  # Children      Self  Command  Shared Object               Symbol
  # ........  ........  .......  ..........................  ..................................
      75.00%     0.00%  true     [kernel.vmlinux]            [k] pgm_check_handler
              |
              ---pgm_check_handler
                 do_dat_exception
                 handle_mm_fault
                 __handle_mm_fault
                 filemap_map_pages
                 |
                 |--25.00%--rcu_read_lock_held
                 |          rcu_lockdep_current_cpu_online
                 |          0x3d1003ff4c0
                 |
                  --25.00%--lock_release

  Looks good to me....
 ----

Reported-and-Tested-by: Thomas-Mich Richter &lt;tmricht@linux.vnet.ibm.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: Zvonko Kosic &lt;zvonko.kosic@de.ibm.com&gt;
Link: http://lkml.kernel.org/n/tip-dk0n1uzmbe0tbthrpfqlx6bz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf annotate: Fix broken arrow at row 0 connecting jmp instruction to its target</title>
<updated>2017-07-10T19:36:40+00:00</updated>
<author>
<name>Jin Yao</name>
<email>yao.jin@linux.intel.com</email>
</author>
<published>2017-06-08T06:01:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=80f62589fa52f530cffc50e78c0b5a2ae572d61e'/>
<id>urn:sha1:80f62589fa52f530cffc50e78c0b5a2ae572d61e</id>
<content type='text'>
When the jump instruction is displayed at the row 0 in annotate view,
the arrow is broken. An example:

 16.86 │   ┌──je     82
  0.01 │      movsd  (%rsp),%xmm0
       │      movsd  0x8(%rsp),%xmm4
       │      movsd  0x8(%rsp),%xmm1
       │      movsd  (%rsp),%xmm3
       │      divsd  %xmm4,%xmm0
       │      divsd  %xmm3,%xmm1
       │      movsd  (%rsp),%xmm2
       │      addsd  %xmm1,%xmm0
       │      addsd  %xmm2,%xmm0
       │      movsd  %xmm0,(%rsp)
       │82:   sub    $0x1,%ebx
 83.03 │    ↑ jne    38
       │      add    $0x10,%rsp
       │      xor    %eax,%eax
       │      pop    %rbx
       │    ← retq

The patch increments the row number before checking with 0.

Signed-off-by: Yao Jin &lt;yao.jin@linux.intel.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: stable@vger.kernel.org
Fixes: 944e1abed9e1 ("perf ui browser: Add method to draw up/down arrow line")
Link: http://lkml.kernel.org/r/1496901704-30275-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf evsel: State in the default event name if attr.exclude_kernel is set</title>
<updated>2017-07-10T19:19:25+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2017-07-10T19:19:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=ede5626d303b721dd02246a3850380943c24e380'/>
<id>urn:sha1:ede5626d303b721dd02246a3850380943c24e380</id>
<content type='text'>
When no event is specified perf will use the "cycles" hardware event
with the highest precision available in the processor, and excluding
kernel events for non-root users, so make that clear in the event name
by setting the "u" event modifier, i.e. "cycles:upp".

E.g.:

The default for root:

  # perf record usleep 1
  # perf evlist -v
  cycles:ppp: ..., precise_ip: 3, exclude_kernel: 0, ...
  #

And for !root:

  $ perf record usleep 1
  $ perf evlist -v
  cycles:uppp: ... , precise_ip: 3, exclude_kernel: 1, ...
  $

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/n/tip-lf29zcdl422i9knrgde0uwy3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf evsel: Fix attr.exclude_kernel setting for default cycles:p</title>
<updated>2017-07-10T19:14:48+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2017-07-10T19:08:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=d37a369790774af66a4aee61a188384d21b17a43'/>
<id>urn:sha1:d37a369790774af66a4aee61a188384d21b17a43</id>
<content type='text'>
To allow probing the max attr.precise_ip setting for non-root users
we unconditionally set attr.exclude_kernel, which makes the detection
work but should be done only for !root, fix it.

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Fixes: 97365e81366f ("perf evsel: Set attr.exclude_kernel when probing max attr.precise_ip")
Link: http://lkml.kernel.org/n/tip-bl6bbxzxloonzvm4nvt7oqgj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'perf-urgent-for-mingo-4.12-20170704' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent</title>
<updated>2017-07-05T07:10:37+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-07-05T07:10:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=524b62fdbef54e8afa37ec8bcdf3ff5723ea160f'/>
<id>urn:sha1:524b62fdbef54e8afa37ec8bcdf3ff5723ea160f</id>
<content type='text'>
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

User visible changes:

 - Fix max attr.precise_ip probing to make perf use the best cycles:p
   available in the processor for non root users (Arnaldo Carvalho de Melo)

 - Fix processing of MMAP events for 32-bit binaries on 64-bit systems
   when unwind support is not fully integrated, fixing DSO and symbol
   resolution (Jiri Olsa)

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf unwind: Do not fail due to missing unwind support</title>
<updated>2017-07-04T14:43:58+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2017-07-04T13:11:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/talos-obmc-linux/commit/?id=1934adf78e33fa69570a763c7ac5353212416bb0'/>
<id>urn:sha1:1934adf78e33fa69570a763c7ac5353212416bb0</id>
<content type='text'>
We currently fail the MMAP event processing if we don't have the MMAP
event's specific arch unwind support compiled in.

That's wrong and can lead to unresolved mmaps in report output for 32bit
binaries on 64bit server, like in this example on x86_64 server:

  $ cat ex.c
  int main(int argc, char **argv)
  {
          while (1) {}
  }
  $ gcc -o ex -m32 ex.c
  $ perf record ./ex
  ^C[ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.371 MB perf.data (9322 samples) ]

Before:
  $ perf report --stdio

  SNIP

  # Overhead  Command  Shared Object     Symbol
  # ........  .......  ................  ......................
  #
     100.00%  ex       [unknown]         [.] 0x00000000080483de
       0.00%  ex       [unknown]         [.] 0x00000000f76dba4f
       0.00%  ex       [unknown]         [.] 0x00000000f76e4c11
       0.00%  ex       [unknown]         [.] 0x00000000f76daa30

After:
  $ perf report --stdio

  SNIP

  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ...............
  #
     100.00%  ex       ex             [.] main
       0.00%  ex       ld-2.24.so     [.] _dl_start
       0.00%  ex       ld-2.24.so     [.] do_lookup_x
       0.00%  ex       ld-2.24.so     [.] _start

The fix is not to fail, just warn if there's not unwind support compiled
in.

Reported-by: Michael Lyle &lt;mlyle@lyle.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/20170704131131.27508-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
</feed>
