Commit Graph

6 Commits

Author SHA1 Message Date
Adrian Hunter
8e0cf965f9 perf symbols: Add support for reading from /proc/kcore
In the absence of vmlinux, perf tools uses kallsyms for symbols.  If the
user has access, now also map to /proc/kcore.

The dso data_type is now set to either DSO_BINARY_TYPE__KCORE or
DSO_BINARY_TYPE__GUEST_KCORE as approprite.

This patch breaks the "vmlinux symtab matches kallsyms" test.  That is
fixed in a following patch.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-07 17:35:33 -03:00
Adrian Hunter
0131c4ec79 perf tools: Make it possible to read object code from kernel modules
The new "object code reading" test shows that it is not possible to read
object code from kernel modules.  That is because the mappings do not
map to the dsos.  This patch fixes that.

This involves identifying and flagging relocatable (ELF type ET_REL)
files (e.g. kernel modules) for symbol adjustment and updating
map__rip_2objdump() accordingly.  The kmodule parameter of
dso__load_sym() is taken into use and the module map altered to map to
the dso.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-07 17:35:32 -03:00
Adrian Hunter
39b12f7812 perf tools: Make it possible to read object code from vmlinux
The new "object code reading" test shows that it is not possible to read
object code from vmlinux.  That is because the mappings do not map to
the dso.  This patch fixes that.

A side-effect of changing the kernel map is that the "reloc" offset must
be taken into account.  As a result of that separate map functions for
relocation are no longer needed.

Also fixing up the maps to match the symbols no longer makes sense and
so is not done.

The vmlinux dso data_type is now set to either DSO_BINARY_TYPE__VMLINUX
or DSO_BINARY_TYPE__GUEST_VMLINUX as approprite, which enables the
correct file name to be determined by dso__binary_type_file().

This patch breaks the "vmlinux symtab matches kallsyms" test.  That is
fixed in a following patch.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-08-07 17:35:31 -03:00
Waiman Long
f9ceffb605 perf symbols: Fix vdso list searching
When "perf record" was used on a large machine with a lot of CPUs, the
perf post-processing time (the time after the workload was done until
the perf command itself exited) could take a lot of minutes and even
hours depending on how large the resulting perf.data file was.

While running AIM7 1500-user high_systime workload on a 80-core x86-64
system with a 3.9 kernel (with only the -s -a options used), the
workload itself took about 2 minutes to run and the perf.data file had a
size of 1108.746 MB. However, the post-processing step took more than 10
minutes.

With a gprof-profiled perf binary, the time spent by perf was as
follows:

  %   cumulative   self              self     total
 time   seconds   seconds    calls   s/call   s/call  name
 96.90    822.10   822.10   192156     0.00     0.00  dsos__find
  0.81    828.96     6.86 172089958     0.00     0.00  rb_next
  0.41    832.44     3.48 48539289     0.00     0.00  rb_erase

So 97% (822 seconds) of the time was spent in a single dsos_find()
function. After analyzing the call-graph data below:

 -----------------------------------------------
                 0.00  822.12  192156/192156      map__new [6]
 [7]     96.9    0.00  822.12  192156         vdso__dso_findnew [7]
               822.10    0.00  192156/192156      dsos__find [8]
                 0.01    0.00  192156/192156      dsos__add [62]
                 0.01    0.00  192156/192366      dso__new [61]
                 0.00    0.00       1/45282525     memdup [31]
                 0.00    0.00  192156/192230      dso__set_long_name [91]
 -----------------------------------------------
               822.10    0.00  192156/192156      vdso__dso_findnew [7]
 [8]     96.9  822.10    0.00  192156         dsos__find [8]
 -----------------------------------------------

It was found that the vdso__dso_findnew() function failed to locate
VDSO__MAP_NAME ("[vdso]") in the dso list and have to insert a new
entry at the end for 192156 times. This problem is due to the fact that
there are 2 types of name in the dso entry - short name and long name.
The initial dso__new() adds "[vdso]" to both the short and long names.
After that, vdso__dso_findnew() modifies the long name to something
like /tmp/perf-vdso.so-NoXkDj. The dsos__find() function only compares
the long name. As a result, the same vdso entry is duplicated many
time in the dso list. This bug increases memory consumption as well
as slows the symbol processing time to a crawl.

To resolve this problem, the dsos__find() function interface was
modified to enable searching either the long name or the short
name. The vdso__dso_findnew() will now search only the short name
while the other call sites search for the long name as before.

With this change, the cpu time of perf was reduced from 848.38s to
15.77s and dsos__find() only accounted for 0.06% of the total time.

  0.06     15.73     0.01   192151     0.00     0.00  dsos__find

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: "Chandramouleeswaran, Aswin" <aswin@hp.com>
Cc: "Norton, Scott J" <scott.norton@hp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1368110568-64714-1-git-send-email-Waiman.Long@hp.com
[ replaced TRUE/FALSE with stdbool.h equivalents, fixing builds where
  those macros are not present (NO_LIBPYTHON=1 NO_LIBPERL=1), fix from Jiri Olsa ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2013-07-08 17:59:07 -03:00
Arnaldo Carvalho de Melo
417c2ff680 perf symbols: Generalize filter in __fprintf_buildid methods
We had that 'with_hits' filter to show just the build ids for DSOs that
had samples, make that generic so that we can use it in the upcoming
buildid-cache --missing feature, to show just the build ids that are not
in the cache.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9nfesdfpnx7zp96yn3tmfbx0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-12-09 08:46:07 -03:00
Jiri Olsa
cdd059d731 perf tools: Move dso_* related functions into dso object
Moving dso_* related functions into dso object.

Keeping symbol loading related functions still in the symbol object as
it seems more convenient.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1351372712-21104-6-git-send-email-jolsa@redhat.com
[ committer note: Use "symbol.h" instead of <symbol.h> to make it build with O= ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-10-29 11:37:25 -02:00