Mathieu Poirier reports issue in commit ("73c0ca1eee3d perf thread_map:
Enumerate all threads from /proc") that it has negative impact on 'perf
record --per-thread'. It has the effect of creating a kernel event for
each thread in the system for 'perf record --per-thread'.
Mathieu Poirier's patch ("perf util: Do not reuse target->per_thread flag")
can fix this issue by creating a new target->all_threads flag.
This patch is based on Mathieu Poirier's patch but it doesn't use a new
target->all_threads flag. This patch just uses 'target->per_thread &&
target->system_wide' as a condition to check for all threads case.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 73c0ca1eee ("perf thread_map: Enumerate all threads from /proc")
Link: http://lkml.kernel.org/r/1518467557-18505-3-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
[Fixed checkpatch warning about line over 80 characters]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The evsel->idx field is used mainly to access the right bucket in
per-event arrays such as the annotation ones, but also to set
evsel->tracking, that in turn will decide what of the events will ask
for PERF_RECORD_{MMAP,COMM,EXEC} to be generated, i.e. which
perf_event_attr will have its mmap, etc fields set.
When we were adding the "dummy" event using perf_evlist__add_dummy() we
were not setting it correctly, which could result in multiple tracking
events.
Now that I'll try using a dummy event to be the tracking one when using
'perf record --delay', i.e. when we process the --delay
setting we may already have the evlist set up, like with:
perf record -e cycles,instructions --delay 1000 ./workload
We will need to add a "dummy" event, then reset evsel->tracking for the
first event, "cycles", and set it instead to the dummy one, and also
setting its attr.enable_on_exec, so that we get the PERF_RECORD_MMAP,
etc metadata events while waiting to enable the explicitely requested
events, so lets get this straight and set the right evsel->idx.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Bram Stolk <b.stolk@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-nrdfchshqxf7diszhxcecqb9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix buffer overflow for:
% perf stat -e msr/tsc/,cstate_core/c7-residency/ true
that causes glibc free list corruption. For some reason it doesn't
trigger in valgrind, but it is visible in AS:
=================================================================
==32681==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000003f5c at pc 0x0000005671ef bp 0x7ffdaaac9ac0 sp 0x7ffdaaac9ab0
READ of size 4 at 0x603000003f5c thread T0
#0 0x5671ee in perf_evsel__close_fd util/evsel.c:1196
#1 0x56c57a in perf_evsel__close util/evsel.c:1717
#2 0x55ed5f in perf_evlist__close util/evlist.c:1631
#3 0x4647e1 in __run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:749
#4 0x4648e3 in run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:767
#5 0x46e1bc in cmd_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:2785
#6 0x52f83d in run_builtin /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:296
#7 0x52fd49 in handle_internal_command /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:348
#8 0x5300de in run_argv /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:392
#9 0x5308f3 in main /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:530
#10 0x7f0672d13400 in __libc_start_main (/lib64/libc.so.6+0x20400)
#11 0x428419 in _start (/home/ak/hle/obj-perf/perf+0x428419)
0x603000003f5c is located 0 bytes to the right of 28-byte region [0x603000003f40,0x603000003f5c)
allocated by thread T0 here:
#0 0x7f0675139020 in calloc (/lib64/libasan.so.3+0xc7020)
#1 0x648a2d in zalloc util/util.h:23
#2 0x648a88 in xyarray__new util/xyarray.c:9
#3 0x566419 in perf_evsel__alloc_fd util/evsel.c:1039
#4 0x56b427 in perf_evsel__open util/evsel.c:1529
#5 0x56c620 in perf_evsel__open_per_thread util/evsel.c:1730
#6 0x461dea in create_perf_stat_counter /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:263
#7 0x4637d7 in __run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:600
#8 0x4648e3 in run_perf_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:767
#9 0x46e1bc in cmd_stat /home/ak/hle/linux-hle-2.6/tools/perf/builtin-stat.c:2785
#10 0x52f83d in run_builtin /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:296
#11 0x52fd49 in handle_internal_command /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:348
#12 0x5300de in run_argv /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:392
#13 0x5308f3 in main /home/ak/hle/linux-hle-2.6/tools/perf/perf.c:530
#14 0x7f0672d13400 in __libc_start_main (/lib64/libc.so.6+0x20400)
The event is allocated with cpus == 1, but freed with cpus == real number
When the evsel close function walks the file descriptors it exceeds the
fd xyarray boundaries and reads random memory.
v2:
Now that xyarrays save their original dimensions we can use these to
iterate the two dimensional fd arrays. Fix some users (close, ioctl) in
evsel.c to use these fields directly. This allows simplifying the code
and dropping quite a few function arguments. Adjust all callers by
removing the unneeded arguments.
The actual perf event reading still uses the original values from the
evsel list.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170811232634.30465-2-andi@firstfloor.org
[ Fix up xy_max_[xy]() -> xyarray__max_[xy]() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Experimenting a bit using cppcheck[1], a static checker brought to my
attention by Colin, reducing the scope of some variables, reducing the
line of source code lines in the process:
$ cppcheck --enable=style tools/perf/util/thread.c
Checking tools/perf/util/thread.c...
[tools/perf/util/thread.c:17]: (style) The scope of the variable 'leader' can be reduced.
[tools/perf/util/thread.c:133]: (style) The scope of the variable 'err' can be reduced.
[tools/perf/util/thread.c:273]: (style) The scope of the variable 'err' can be reduced.
Will continue later, but these are already useful, keep them.
1: https://sourceforge.net/p/cppcheck/wiki/Home/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ixws7lbycihhpmq9cc949ti6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In systems with heterogeneous CPU PMUs, it's possible for each evsel to
cover a distinct set of CPUs, and hence the cpu_map associated with each
evsel may have a distinct idx<->id mapping. Any of these may be distinct
from the evlist's cpu map.
Events can be tied to the same fd so long as they use the same per-cpu
ringbuffer (i.e. so long as they are on the same CPU). To acquire the
correct FDs, we must compare the Linux logical IDs rather than the evsel
or evlist indices.
This path adds logic to perf_evlist__mmap_per_evsel to handle this,
translating IDs as required. As PMUs may cover a subset of CPUs from the
evlist, we skip the CPUs a PMU cannot handle.
Without this patch, perf record may try to mmap erroneous FDs on
heterogeneous systems, and will bail out early rather than running the
workload.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1473330112-28528-7-git-send-email-mark.rutland@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Introduce a bkw_mmap_state state machine to evlist:
.________________(forbid)_____________.
| V
NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
^ ^ | ^ |
| |__(forbid)____/ |___(forbid)___/|
| |
\_________________(3)_______________/
NOTREADY : Backward ring buffers are not ready
RUNNING : Backward ring buffers are recording
DATA_PENDING : We are required to collect data from backward ring buffers
EMPTY : We have collected data from backward ring buffers.
(0): Setup backward ring buffer
(1): Pause ring buffers for reading
(2): Read from ring buffers
(3): Resume ring buffers for recording
We can't avoid this complexity. Since we deliberately drop records from
overwritable ring buffer, there's no way for us to check remaining from
ring buffer itself (by checking head and old pointers). Therefore, we
need DATA_PENDING and EMPTY state to help us recording what we have done
to the ring buffer.
In record__mmap_read_evlist(), drive this state machine from DATA_PENDING
to EMPTY.
In perf_evlist__mmap_per_evsel(), drive this state machine from NOTREADY
to RUNNING when creating backward mmap.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468485287-33422-11-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently, the evlist mmap related helpers and APIs accept evlist and
idx, and dereference 'struct perf_mmap' by evlist->mmap[idx]. This is
unnecessary, and force each evlist contains only one mmap array.
Following commits are going to introduce multiple mmap arrays to a
evlist. This patch refators these APIs and helpers, introduces
functions accept perf_mmap pointer directly. New helpers and APIs are
decoupled with perf_evlist, and become perf_mmap functions (so they have
perf_mmap prefix).
Old functions are reimplemented with new functions. Some of them will be
removed in following commits.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468485287-33422-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.
But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.
So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
