Save samples with deferred callchains in a separate list and deliver
them after merging the user callchains. If users don't want to merge
they can set tool->merge_deferred_callchains to false to prevent the
behavior.
With previous result, now perf script will show the merged callchains.
$ perf script
...
pwd 2312 121.163435: 249113 cpu/cycles/P:
ffffffff845b78d8 __build_id_parse.isra.0+0x218 ([kernel.kallsyms])
ffffffff83bb5bf6 perf_event_mmap+0x2e6 ([kernel.kallsyms])
ffffffff83c31959 mprotect_fixup+0x1e9 ([kernel.kallsyms])
ffffffff83c31dc5 do_mprotect_pkey+0x2b5 ([kernel.kallsyms])
ffffffff83c3206f __x64_sys_mprotect+0x1f ([kernel.kallsyms])
ffffffff845e6692 do_syscall_64+0x62 ([kernel.kallsyms])
ffffffff8360012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms])
7f18fe337fa7 mprotect+0x7 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
7f18fe330e0f _dl_sysdep_start+0x7f (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
7f18fe331448 _dl_start_user+0x0 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
...
The old output can be get using --no-merge-callchain option.
Also perf report can get the user callchain entry at the end.
$ perf report --no-children --stdio -q -S __build_id_parse.isra.0
# symbol: __build_id_parse.isra.0
8.40% pwd [kernel.kallsyms]
|
---__build_id_parse.isra.0
perf_event_mmap
mprotect_fixup
do_mprotect_pkey
__x64_sys_mprotect
do_syscall_64
entry_SYSCALL_64_after_hwframe
mprotect
_dl_sysdep_start
_dl_start_user
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Add a new event type for deferred callchains and a new callback for the
struct perf_tool. For now it doesn't actually handle the deferred
callchains but it just marks the sample if it has the PERF_CONTEXT_
USER_DEFFERED in the callchain array.
At least, perf report can dump the raw data with this change. Actually
this requires the next commit to enable attr.defer_callchain, but if you
already have a data file, it'll show the following result.
$ perf report -D
...
0x2158@perf.data [0x40]: event: 22
.
. ... raw event: size 64 bytes
. 0000: 16 00 00 00 02 00 40 00 06 00 00 00 0b 00 00 00 ......@.........
. 0010: 03 00 00 00 00 00 00 00 a7 7f 33 fe 18 7f 00 00 ..........3.....
. 0020: 0f 0e 33 fe 18 7f 00 00 48 14 33 fe 18 7f 00 00 ..3.....H.3.....
. 0030: 08 09 00 00 08 09 00 00 e6 7a e7 35 1c 00 00 00 .........z.5....
121163447014 0x2158 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 2312/2312: 0xb00000006
... FP chain: nr:3
..... 0: 00007f18fe337fa7
..... 1: 00007f18fe330e0f
..... 2: 00007f18fe331448
: unhandled!
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Add an ability to be able to compose perf_tools, by having one perform
an action and then calling a delegate. Currently the perf_tools have
if-then-elses setting the callback and then if-then-elses within the
callback. Understanding the behavior is complex as it is in two places
and logic for numerous operations, within things like perf inject, is
interwoven. By chaining perf_tools together based on command line
options this kind of code can be avoided.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Getting context for what a tool is doing, such as the perf_inject
instance, using container_of the tool is a common pattern in the
code. This isn't possible event_op2, event_op3 and event_op4 callbacks
as the tool isn't passed. Add the argument and then fix function
signatures to match. As tools maybe reading a tool from somewhere
else, change that code to use the passed in tool.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
The original PERF_RECORD_COMPRESS is not 8-byte aligned, which can cause
asan runtime error:
# Build with asan
$ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined"
# Test success with many asan runtime errors:
$ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv
83: Zstd perf.data compression/decompression:
...
util/session.c:1959:13: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 13 byte alignment
0x7f69e3f99653: note: pointer points here
d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00
^
util/session.c:2163:22: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 8 byte alignment
0x7f69e3f99653: note: pointer points here
d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00
^
...
Since there is no way to align compressed data in zstd compression, this
patch add a new event type `PERF_RECORD_COMPRESSED2`, which adds a field
`data_size` to specify the actual compressed data size.
The `header.size` contains the total record size, including the padding
at the end to make it 8-byte aligned.
Tested with `Zstd perf.data compression/decompression`
Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250303183646.327510-1-ctshao@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
