Before, when some problem happened while trying to load the kernel
symtab, 'perf top' would show:
┌─Warning:───────────────────────────┐
│The vmlinux file can't be used. │
│Kernel samples will not be resolved.│
│ │
│ │
│Press any key... │
└────────────────────────────────────┘
Now, it reports:
# perf top --vmlinux /dev/null
┌─Warning:───────────────────────────────────────────┐
│The /tmp/passwd file can't be used: Invalid ELF file│
│Kernel samples will not be resolved. │
│ │
│ │
│Press any key... │
└────────────────────────────────────────────────────┘
This is possible because we now register the reason for not being able
to load the symtab in the dso->load_errno member, and provide a
dso__strerror_load() routine to format this error into a strerror like
string with a short reason for the error while loading.
That can be just forwarding the dso__strerror_load() call to
strerror_r(), or, for a separate errno range providing a custom message.
Reported-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-u5rb5uq63xqhkfb8uv2lxd5u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Provides united way of parsing kernel module path
into several components.
The new kmod_path__parse function and few defines:
int __kmod_path__parse(struct kmod_path *m, const char *path,
bool alloc_name, bool alloc_ext);
#define kmod_path__parse(__m, __p) __kmod_path__parse(__m, __p, false, false)
#define kmod_path__parse_name(__m, __p) __kmod_path__parse(__m, __p, true , false)
#define kmod_path__parse_ext(__m, __p) __kmod_path__parse(__m, __p, false, true)
parse kernel module @path and updates @m argument like:
@comp - true if @path contains supported compression suffix,
false otherwise
@kmod - true if @path contains '.ko' suffix in right position,
false otherwise
@name - if (@alloc_name && @kmod) is true, it contains strdup-ed base name
of the kernel module without suffixes, otherwise strudup-ed
base name of @path
@ext - if (@alloc_ext && @comp) is true, it contains strdup-ed string
the compression suffix
It returns 0 if there's no strdup error, -ENOMEM otherwise.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
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/n/tip-9t6eqg8j610r94l743hkntiv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now my Archlinux box shows module symbols correctly.
Before:
$ perf report --stdio
Failed to open /tmp/perf-3477.map, continuing without symbols
no symbols found in /usr/bin/date, maybe install a debug package?
No kallsyms or vmlinux with build-id 7b4ea0a49ae2111925857099aaf05c3246ff33e0 was found
[drm] with build id 7b4ea0a49ae2111925857099aaf05c3246ff33e0 not found, continuing without symbols
No kallsyms or vmlinux with build-id edd931629094b660ca9dec09a1b635c8d87aa2ee was found
[jbd2] with build id edd931629094b660ca9dec09a1b635c8d87aa2ee not found, continuing without symbols
No kallsyms or vmlinux with build-id a7b1eada671c34933e5610bb920b2ca4945a82c3 was found
[ext4] with build id a7b1eada671c34933e5610bb920b2ca4945a82c3 not found, continuing without symbols
No kallsyms or vmlinux with build-id d69511fa3e5840e770336ef45b06c83fef8d74e3 was found
[scsi_mod] with build id d69511fa3e5840e770336ef45b06c83fef8d74e3 not found, continuing without symbols
No kallsyms or vmlinux with build-id af0430af13461af058770ee9b87afc07922c2e77 was found
[libata] with build id af0430af13461af058770ee9b87afc07922c2e77 not found, continuing without symbols
No kallsyms or vmlinux with build-id aaeedff8160ce631a5f0333591c6ff291201d29f was found
[libahci] with build id aaeedff8160ce631a5f0333591c6ff291201d29f not found, continuing without symbols
No kallsyms or vmlinux with build-id c57907712becaf662dc4981824bb372c0441d605 was found
[mac80211] with build id c57907712becaf662dc4981824bb372c0441d605 not found, continuing without symbols
No kallsyms or vmlinux with build-id e0589077cc0ec8c3e4c40eb9f2d9e69d236bee8f was found
[iwldvm] with build id e0589077cc0ec8c3e4c40eb9f2d9e69d236bee8f not found, continuing without symbols
No kallsyms or vmlinux with build-id 2d86086bf136bf374a2f029cf85a48194f9b950b was found
[cfg80211] with build id 2d86086bf136bf374a2f029cf85a48194f9b950b not found, continuing without symbols
No kallsyms or vmlinux with build-id 4493c48599bdb3d91d0f8db5150e0be33fdd9221 was found
[iwlwifi] with build id 4493c48599bdb3d91d0f8db5150e0be33fdd9221 not found, continuing without symbols
...
#
# Overhead Command Shared Object Symbol
# ........ ............... ....................... ........................................................
#
0.03% swapper [ext4] [k] 0x000000000000fe2e
0.03% swapper [kernel.kallsyms] [k] account_entity_enqueue
0.03% swapper [ext4] [k] 0x000000000000fc2b
0.03% irq/50-iwlwifi [iwlwifi] [k] 0x000000000000200b
0.03% swapper [kernel.kallsyms] [k] ktime_add_safe
0.03% swapper [kernel.kallsyms] [k] elv_completed_request
0.03% swapper [libata] [k] 0x0000000000003997
0.03% swapper [libahci] [k] 0x0000000000001f25
0.03% swapper [kernel.kallsyms] [k] rb_next
0.03% swapper [kernel.kallsyms] [k] blk_finish_request
0.03% swapper [ext4] [k] 0x0000000000010248
0.00% perf [kernel.kallsyms] [k] native_write_msr_safe
After:
$ perf report --stdio
Failed to open /tmp/perf-3477.map, continuing without symbols
no symbols found in /usr/bin/tr, maybe install a debug package?
...
#
# Overhead Command Shared Object Symbol
# ........ ............... ........................... ......................................................
#
0.04% kworker/u16:3 [ext4] [k] ext4_read_block_bitmap
0.03% kworker/u16:0 [mac80211] [k] ieee80211_sta_reset_beacon_monitor
0.02% irq/50-iwlwifi [mac80211] [k] ieee80211_get_bssid
0.02% firefox [e1000e] [k] __ew32_prepare
0.02% swapper [libahci] [k] ahci_handle_port_interrupt
0.02% emacs libglib-2.0.so.0.4000.0 [.] g_mutex_unlock
0.02% swapper [e1000e] [k] e1000_clean_tx_irq
0.02% dwm [kernel.kallsyms] [k] __schedule
0.02% gnome-terminal- [vdso] [.] __vdso_clock_gettime
0.02% swapper [e1000e] [k] e1000_alloc_rx_buffers
0.02% irq/50-iwlwifi [mac80211] [k] ieee80211_rx
0.01% firefox [vdso] [.] __vdso_gettimeofday
0.01% irq/50-iwlwifi [iwlwifi] [k] iwl_pcie_rxq_restock.part.13
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/87h9yexshi.fsf@sejong.aot.lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With workload that spawns and destroys many threads and processes, it
was found that perf-mem could took a long time to post-process the perf
data after the target workload had completed its operation.
The performance bottleneck was found to be the lookup and insertion of
the new DSO structures (thousands of them in this case).
In a dual-socket Ivy-Bridge E7-4890 v2 machine (30-core, 60-thread), the
perf profile below shows what perf was doing after the profiled AIM7
shared workload completed:
- 83.94% perf libc-2.11.3.so [.] __strcmp_sse42
- __strcmp_sse42
- 99.82% map__new
machine__process_mmap_event
perf_session_deliver_event
perf_session__process_event
__perf_session__process_events
cmd_record
cmd_mem
run_builtin
main
__libc_start_main
- 13.17% perf perf [.] __dsos__findnew
__dsos__findnew
map__new
machine__process_mmap_event
perf_session_deliver_event
perf_session__process_event
__perf_session__process_events
cmd_record
cmd_mem
run_builtin
main
__libc_start_main
So about 97% of CPU times were spent in the map__new() function trying
to insert new DSO entry into the DSO linked list. The whole
post-processing step took about 9 minutes.
The DSO structures are currently searched linearly. So the total
processing time will be proportional to n^2.
To overcome this performance problem, the DSO code is modified to also
put the DSO structures in a RB tree sorted by its long name in
additional to being in a simple linked list. With this change, the
processing time will become proportional to n*log(n) which will be much
quicker for large n. However, the short name will still be searched
using the old linear searching method. With that patch in place, the
same perf-mem post-processing step took less than 30 seconds to
complete.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Link: http://lkml.kernel.org/r/1412098575-27863-3-git-send-email-Waiman.Long@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Caching dso data file descriptors to avoid expensive re-opens
especially during DWARF unwind.
We keep dsos data file descriptors open until their count reaches
the half of the current fd open limit (RLIMIT_NOFILE). In this case
we close file descriptor of the first opened dso object.
We've got overall speedup (~27% for my workload) of report:
'perf report --stdio -i perf-test.data' (3 runs)
(perf-test.data size was around 12GB)
current code:
545,640,944,228 cycles ( +- 0.53% )
785,255,798,320 instructions ( +- 0.03% )
366.340910010 seconds time elapsed ( +- 3.65% )
after change:
435,895,036,114 cycles ( +- 0.26% )
636,790,271,176 instructions ( +- 0.04% )
266.481463387 seconds time elapsed ( +- 0.13% )
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
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/1401892622-30848-7-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
It was called "data_type", but in this context "data" is way too vague,
it could mean the "data" ELF segment, or something else.
Since we have dso__read_binary_type_filename() and the values this field
receives are all DSO__BINARY_TYPE_<FOO> we may as well call it
"binary_type" for consistency sake.
It also seems more appropriate since it determines if we can do
operations like annotation and DWARF unwinding, that needs more than
just the symtab, requiring access to ELF text segments, CFI ELF
sections, etc.
Cc: Adrian Hunter <adrian.hunter@intel.com>
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@kernel.org>
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-2lkbqrn23uc2uvnn9w9in379@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The basename() implementation varies a lot between systems.
The Linux man page says: "basename may modify the content of the path,
so it may be desirable to pass a copy when calling the function".
On some other systems, the returned address may come from an internal
buffer which can be reused in subsequent calls, thus the results should
also be copied.
The dso__set_basename() function was not doing this causing problems
on some systems with wrong library names being shown by perf report,
such as on Android systems.
This patch fixes the problem.
The patch is relative to tip.git.
In v2, we clean up the comments based on Ingo's feedback.
Reported-by: Ben Cheng <bccheng@google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Ben Cheng <bccheng@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131205182642.GA14614@quad
[ v3: Fixed up wrt allocated flag now being set in dso__set_short_name ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
