linux-toradex.git/tools/perf/util/header.c, branch v3.0.16

perf tools: Fix endian conversion reading event attr from file header

2011-08-05T04:58:35+00:00

commit eda3913bb70ecebac13adccffe1e7f96e93cee02 upstream.

The perf_event_attr struct has two __u32's at the top and
they need to be swapped individually.

With this change I was able to analyze a perf.data collected in a
32-bit PPC VM on an x86 system. I tested both 32-bit and 64-bit
binaries for the Intel analysis side; both read the PPC perf.data
file correctly.

-v2:
 - changed the existing perf_event__attr_swap() to swap only elements
   of perf_event_attr and exported it for use in swapping the
   attributes in the file header
 - updated swap_ops used for processing events

Signed-off-by: David Ahern 
Acked-by: Frederic Weisbecker 
Cc: acme@ghostprotocols.net
Cc: peterz@infradead.org
Cc: paulus@samba.org
Link: http://lkml.kernel.org/r/1310754849-12474-1-git-send-email-dsahern@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

perf symbols: Handle /proc/sys/kernel/kptr_restrict

2011-05-26T14:15:25+00:00

Perf uses /proc/modules to figure out where kernel modules are loaded.

With the advent of kptr_restrict, non root users get zeroes for all module
start addresses.

So check if kptr_restrict is non zero and don't generate the syntethic
PERF_RECORD_MMAP events for them.

Warn the user about it in perf record and in perf report.

In perf report the reference relocation symbol being zero means that
kptr_restrict was set, thus /proc/kallsyms has only zeroed addresses, so don't
use it to fixup symbol addresses when using a valid kallsyms (in the buildid
cache) or vmlinux (in the vmlinux path) build-id located automatically or
specified by the user.

Provide an explanation about it in 'perf report' if kernel samples were taken,
checking if a suitable vmlinux or kallsyms was found/specified.

Restricted /proc/kallsyms don't go to the buildid cache anymore.

Example:

 [acme@emilia ~]$ perf record -F 100000 sleep 1

 WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, check
 /proc/sys/kernel/kptr_restrict.

 Samples in kernel functions may not be resolved if a suitable vmlinux file is
 not found in the buildid cache or in the vmlinux path.

 Samples in kernel modules won't be resolved at all.

 If some relocation was applied (e.g. kexec) symbols may be misresolved even
 with a suitable vmlinux or kallsyms file.

 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.005 MB perf.data (~231 samples) ]
 [acme@emilia ~]$

 [acme@emilia ~]$ perf report --stdio
 Kernel address maps (/proc/{kallsyms,modules}) were restricted,
 check /proc/sys/kernel/kptr_restrict before running 'perf record'.

 If some relocation was applied (e.g. kexec) symbols may be misresolved.

 Samples in kernel modules can't be resolved as well.

 # Events: 13  cycles
 #
 # Overhead  Command      Shared Object                 Symbol
 # ........  .......  .................  .....................
 #
    20.24%    sleep  [kernel.kallsyms]  [k] page_fault
    20.04%    sleep  [kernel.kallsyms]  [k] filemap_fault
    19.78%    sleep  [kernel.kallsyms]  [k] __lru_cache_add
    19.69%    sleep  ld-2.12.so         [.] memcpy
    14.71%    sleep  [kernel.kallsyms]  [k] dput
     4.70%    sleep  [kernel.kallsyms]  [k] flush_signal_handlers
     0.73%    sleep  [kernel.kallsyms]  [k] perf_event_comm
     0.11%    sleep  [kernel.kallsyms]  [k] native_write_msr_safe

 #
 # (For a higher level overview, try: perf report --sort comm,dso)
 #
 [acme@emilia ~]$

This is because it found a suitable vmlinux (build-id checked) in
/lib/modules/2.6.39-rc7+/build/vmlinux (use -v in perf report to see the long
file name).

If we remove that file from the vmlinux path:

 [root@emilia ~]# mv /lib/modules/2.6.39-rc7+/build/vmlinux \
		     /lib/modules/2.6.39-rc7+/build/vmlinux.OFF
 [acme@emilia ~]$ perf report --stdio
 [kernel.kallsyms] with build id 57298cdbe0131f6871667ec0eaab4804dcf6f562
 not found, continuing without symbols

 Kernel address maps (/proc/{kallsyms,modules}) were restricted, check
 /proc/sys/kernel/kptr_restrict before running 'perf record'.

 As no suitable kallsyms nor vmlinux was found, kernel samples can't be
 resolved.

 Samples in kernel modules can't be resolved as well.

 # Events: 13  cycles
 #
 # Overhead  Command      Shared Object  Symbol
 # ........  .......  .................  ......
 #
    80.31%    sleep  [kernel.kallsyms]  [k] 0xffffffff8103425a
    19.69%    sleep  ld-2.12.so         [.] memcpy

 #
 # (For a higher level overview, try: perf report --sort comm,dso)
 #
 [acme@emilia ~]$

Reported-by: Stephane Eranian 
Suggested-by: David Miller 
Cc: Dave Jones 
Cc: David Miller 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
Link: http://lkml.kernel.org/n/tip-mt512joaxxbhhp1odop04yit@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Move evlist sample helpers to evlist area

2011-05-22T01:12:29+00:00

These APIs should belong to evlist.c as they may not be
exclusively tied to the headers.

Signed-off-by: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Stephane Eranian

perf build-id: Add quirk to deal with perf.data file format breakage

2011-03-23T22:29:40+00:00

The a1645ce1 changeset:

"perf: 'perf kvm' tool for monitoring guest performance from host"

Added a field to struct build_id_event that broke the file format.

Since the kernel build-id is the first entry, process the table using
the old format if the well known '[kernel.kallsyms]' string for the
kernel build-id has the first 4 characters chopped off (where the pid_t
sits).

Reported-by: Han Pingtian 
Cc: Avi Kivity 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
Cc: Zhang Yanmin 
Cc: stable@kernel.org
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-16T01:31:30+00:00

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (184 commits)
  perf probe: Clean up probe_point_lazy_walker() return value
  tracing: Fix irqoff selftest expanding max buffer
  tracing: Align 4 byte ints together in struct tracer
  tracing: Export trace_set_clr_event()
  tracing: Explain about unstable clock on resume with ring buffer warning
  ftrace/graph: Trace function entry before updating index
  ftrace: Add .ref.text as one of the safe areas to trace
  tracing: Adjust conditional expression latency formatting.
  tracing: Fix event alignment: skb:kfree_skb
  tracing: Fix event alignment: mce:mce_record
  tracing: Fix event alignment: kvm:kvm_hv_hypercall
  tracing: Fix event alignment: module:module_request
  tracing: Fix event alignment: ftrace:context_switch and ftrace:wakeup
  tracing: Remove lock_depth from event entry
  perf header: Stop using 'self'
  perf session: Use evlist/evsel for managing perf.data attributes
  perf top: Don't let events to eat up whole header line
  perf top: Fix events overflow in top command
  ring-buffer: Remove unused #include 
  tracing: Add an 'overwrite' trace_option.
  ...

perf header: Stop using 'self'

2011-03-10T14:16:28+00:00

Stop using this python/OOP convention, doesn't really helps. Will do
more from time to time till we get it cleaned up in all of tools/perf.

Suggested-by: Thomas Gleixner 
LKML-Reference: 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Tom Zanussi 
Signed-off-by: Arnaldo Carvalho de Melo

perf session: Use evlist/evsel for managing perf.data attributes

2011-03-10T14:15:54+00:00

So that we can reuse things like the id to attr lookup routine
(perf_evlist__id2evsel) that uses a hash table instead of the linear
lookup done in the older perf_header_attr routines, etc.

Also to make evsels/evlist more pervasive an API, simplyfing using the
emerging perf lib.

cc: Arun Sharma 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Avoid resolving [kernel.kallsyms] to real path for buildid cache

2011-03-09T16:44:10+00:00

kallsyms has a virtual file name [kernel.kallsyms].  Currently, it can't
be added to buildid cache successfully because the code
(build_id_cache__add_s) tries to resolve [kernel.kallsyms] to a real
absolute pathname and that fails.

Fixes it by not resolving it and just use the name [kernel.kallsyms].
So dir ~/.debug/[kernel.kallsyms] is created.

Original bug report at:
https://lkml.org/lkml/2011/3/1/524

Tested-by: Han Pingtian 
Cc: Han Pingtian 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
LKML-Reference: <1299165837-27817-1-git-send-email-ming.m.lin@intel.com>
Signed-off-by: Lin Ming 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Improve support for sessions with multiple events

2011-03-06T16:13:40+00:00

By creating an perf_evlist out of the attributes in the perf.data file
header, so that we can use evlists and evsels when reading recorded
sessions in addition to when we record sessions.

More work is needed to allow tools to allow the user to select which
events are wanted when browsing sessions, be it just one or a subset of
them, aggregated or showed at the same time but with different
indications on the UI to allow seeing workloads thru different views at
the same time.

But the overall goal/trend is to more uniformly use evsels and evlists.

Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

perf tool: Fix gcc 4.6.0 issues

2011-02-07T14:41:41+00:00

GCC 4.6.0 in Fedora rawhide turned up some compile errors in tools/perf
due to the -Werror=unused-but-set-variable flag.

I've gone through and annotated some of the assignments that had side
effects (ie: return value from a function) with the __used annotation,
and in some cases, just removed unused code.

In a few cases, we were assigning something useful, but not using it in
later parts of the function.

kyle@dreadnought:~/src% gcc --version
gcc (GCC) 4.6.0 20110122 (Red Hat 4.6.0-0.3)

Cc: Ingo Molnar 
LKML-Reference: <20110124161304.GK27353@bombadil.infradead.org>
Signed-off-by: Kyle McMartin 
[ committer note: Fixed up the annotation fixes, as that code moved recently ]
Signed-off-by: Arnaldo Carvalho de Melo