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  1. 11 Nov, 2009 4 commits
    • Frederic Weisbecker's avatar
      perf tools: Read the build-ids from the header layer · 4778d2e4
      Frederic Weisbecker authored 
      Keep the build-ids reading implementation in the data mapping
but move its call to the headers so that we have a better
control on it (offset seeking, size passing, etc..).
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      4778d2e4
    • Frederic Weisbecker's avatar
      perf tools: Split up build id saving into fetch and write · 57f395a7
      Frederic Weisbecker authored 
      We are saving the build id once we stop the profiling. And only
after doing that we know if we need to set that feature in the
header through the feature bitmap.

But if we want a proper feature support in the headers, using a
rule of offset/size pairs in sections, we need to know in
advance how many features we need to set in the headers, so that
we can reserve rooms for their section headers.

The current state doesn't allow that, as it forces us to first
save the build-ids to the file right after the datas instead of
planning any structured layout.

That's why this splits up the build-ids processing in two parts:
one that fetches the build-ids from the Dso objects, and one
that saves them into the file.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      57f395a7
    • Frederic Weisbecker's avatar
      perf tools: Move the build-id storage operations to headers · 8671dab9
      Frederic Weisbecker authored 
      So that it makes easier to control it. Especially because we
plan to give it a feature section.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      8671dab9
    • Frederic Weisbecker's avatar
      perf tools: Synthetize the targeted process · de896721
      Frederic Weisbecker authored 
      Don't forget to also synthetize the targeted process from perf
record or we'll miss its dso in the events and then we won't be
able to deal with its build-id.

We are missing it because it is created after the existing
synthetized tasks but before the counters are enabled and can
send its mapping event.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      de896721
  3. 09 Nov, 2009 1 commit
  5. 08 Nov, 2009 3 commits
    • Clark Williams's avatar
      perf tools: Modify perf routines to use new debugfs routines · 549104f2
      Clark Williams authored 
      modify perf.c get_debugfs_mntpnt() to use the util/debugfs.c
debugfs_find_mountpoint()

modify util/parse-events.c to use debugfs_valid_mountpoint().
Signed-off-by: default avatarClark Williams <williams@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091101155720.624cc87e@torg>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      549104f2
    • Clark Williams's avatar
      perf tools: Add debugfs utility routines for perf · afe61f67
      Clark Williams authored 
      Add routines to locate the debugfs mount point and to manage the
mounting and unmounting of the debugfs.
Signed-off-by: default avatarClark Williams <williams@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091101155621.2b3503ee@torg>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      afe61f67
    • Arnaldo Carvalho de Melo's avatar
      perf symbols: Use the buildids if present · 8d06367f
      Arnaldo Carvalho de Melo authored 
      With this change 'perf record' will intercept PERF_RECORD_MMAP
calls, creating a linked list of DSOs, then when the session
finishes, it will traverse this list and read the buildids,
stashing them at the end of the file and will set up a new
feature bit in the header bitmask.

'perf report' will then notice this feature and populate the
'dsos' list and set the build ids.

When reading the symtabs it will refuse to load from a file that
doesn't have the same build id. This improves the
reliability of the profiler output, as symbols and profiling
data is more guaranteed to match.

Example:

 [root@doppio ~]# perf report | head
 /home/acme/bin/perf with build id b1ea544ac3746e7538972548a09aadecc5753868 not found, continuing without symbols
  # Samples: 2621434559
  #
  # Overhead          Command                  Shared Object  Symbol
  # ........  ...............  .............................  ......
  #
       7.91%             init  [kernel]        [k] read_hpet
       7.64%             init  [kernel]        [k] mwait_idle_with_hints
       7.60%          swapper  [kernel]        [k] read_hpet
       7.60%          swapper  [kernel]        [k] mwait_idle_with_hints
       3.65%             init  [kernel]        [k] 0xffffffffa02339d9
[root@doppio ~]#

In this case the 'perf' binary was an older one, vanished,
so its symbols probably wouldn't match or would cause subtly
different (and misleading) output.

Next patches will support the kernel as well, reading the build
id notes for it and the modules from /sys.

Another patch should also introduce a new plumbing command:

'perf list-buildids'

that will then be used in porcelain that is distro specific to
fetch -debuginfo packages where such buildids are present. This
will in turn allow for one to run 'perf record' in one machine
and 'perf report' in another.

Future work on having the buildid sent directly from the kernel
in the PERF_RECORD_MMAP event is needed to close races, as the
DSO can be changed during a 'perf record' session, but this
patch at least helps with non-corner cases and current/older
kernels.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1257367843-26224-1-git-send-email-acme@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      8d06367f
  7. 04 Nov, 2009 2 commits
  9. 03 Nov, 2009 28 commits
  11. 02 Nov, 2009 2 commits
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