The validation checks that the values that were just assigned, got
assigned i.e. the error can't ever happen. Subsequent patches will call
this code in places where errors are not being returned. Changing those
code paths to return this non-existent error is counter-productive, so
just remove it.
That in turn results in perf_evlist__set_maps not needing to return an
error, but callers aren't checking it either, so remove that too.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/1441699142-18905-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Patch "perf script: Don't assume evsel position of tracking events"
changed 'perf script' to use 'perf_evlist__id2evsel()'. That results
in a segfault if there is more than 1 event and there are
synthesized mmap events e.g.
$ perf record -e cycles,instructions -p$$ sleep 1
$ perf script --show-mmap-events
Segmentation fault (core dumped)
That happens because these synthesized events have an 'id' of zero
which does not match any 'evsel'.
Currently, these synthesized events use the sample type of the first
evsel.
Change 'perf_evlist__id2evsel()' to reflect that which also makes
it consistent with 'perf_evlist__event2evsel()'.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: 06b234ec26 ("perf script: Don't assume evsel position of tracking events")
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1440059205-1765-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Instead of calling perf_evsel__apply_filter straight away, so that
we can, in the next patches, expand the filter with more conditions
before actually calling the ioctl to pass the end result filter to
the kernel.
Now we need to call perf_evlist__apply_filters() after the filter
is completely setup, i.e. do the ioctl calls.
The perf_evlist__apply_filters() method was already in place, because
that is the model for the other tools that receives filters in the
command line: go on setting then in the evsel->filter and only at
the end, after parsing the whole command line, apply them.
We get, as a bonus, a more expressive message that states which
event, if any, failed to have the filter applied to, with an
error message stating what happened.
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: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-f429pgz75ryz7tpe6v74etre@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We need to be able to go on constructing a complex filter in multiple
stages, since we can only set one filter per event.
For instance, we need to be able, in 'perf trace' to filter by the
'common_pid' field all the time, if only for the tracer itself, to
avoid a feedback loop, and, in addition, we may want to filter the
raw_syscalls:sys_{enter,exit} events by its 'id' filter, when using
'perf trace -e open,close' or 'perf trace -e !open,close', i.e. when
we are interested in just a subset of syscalls or when we are not
interested in it.
So we will have:
perf_evsel__set_filter(evsel, char *filter)
Replaces whatever is in evsel->filter.
perf_evsel__append_filter(evsel, const char *op, char *filter)
Appends, using op ("&&" or "||") with what is in evsel->filter.
perf_evsel__apply_filter(evsel, filter):
That actually applies a filter, be it the one being
constructed in evsel->filter, or any other, for tools
with more specific ways to build the filter, issuing
the appropriate ioctl for all the evsel fds.
The same changes will be made to the evlist__{set,apply} variants to
keep everything consistent.
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: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2s5z9xtpnc2lwio3cv5x0jek@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
I get following crash on multiple systems and across several releases
(at least since v3.18).
Core was generated by `/tmp/perf trace sleep 0.2 '.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 perf_mmap__read_head (mm=0x3fff9bf30070) at util/evlist.h:195
195 u64 head = ACCESS_ONCE(pc->data_head);
(gdb) bt
#0 perf_mmap__read_head (mm=0x3fff9bf30070) at util/evlist.h:195
#1 perf_evlist__mmap_read (evlist=0x10027f11910, idx=<optimized out>)
at util/evlist.c:637
#2 0x000000001003ce4c in trace__run (argv=<optimized out>,
argc=<optimized out>, trace=0x3fffd7b28288) at builtin-trace.c:2259
#3 cmd_trace (argc=<optimized out>, argv=<optimized out>,
prefix=<optimized out>) at builtin-trace.c:2799
#4 0x00000000100657b8 in run_builtin (p=0x10176798 <commands+480>, argc=3,
argv=0x3fffd7b2b550) at perf.c:370
#5 0x00000000100063e8 in handle_internal_command (argv=0x3fffd7b2b550, argc=3)
at perf.c:429
#6 run_argv (argv=0x3fffd7b2af70, argcp=0x3fffd7b2af7c) at perf.c:473
#7 main (argc=3, argv=0x3fffd7b2b550) at perf.c:588
The problem seems to be a race condition, when the application has just
exited. Some/all fds associated with the perf-events (tracepoints) go
into a POLLHUP/ POLLERR state and the mmap region associated with those
events are unmapped (in perf_evlist__filter_pollfd()).
But we go back and do a perf_evlist__mmap_read() which assumes that the
mmaps are still valid and we hit the crash.
If the mapping for an event is released, its refcnt is 0 (and ->base
is NULL), so ensure we have non-zero refcount before accessing the map.
Note that perf-record has a similar logic but unlike perf-trace, the
record__mmap_read_all() checks the evlist->mmap[i].base before accessing
the map.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Zhang <zhlcindy@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150612060003.GA19913@us.ibm.com
[ Fixed it up to use atomic_read() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch supports the addition to the kernel of AUX area buffers that
can be mmapped separately from the perf-events buffer.
The AUX buffer can be configured to contain hardware-produced trace
information. The first implementation will support Intel BTS and Intel
PT.
One auxtrace buffer is mmapped per perf-events buffer. If the requested
auxtrace buffer size is zero, which it will be until further support is
added, then no auxtrace mmapping is attempted.
Signed-off-by: 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: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-3-git-send-email-adrian.hunter@intel.com
[ Fixed conflict in evlist.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use of a bad filter currently generates the message:
Error: failed to set filter with 22 (Invalid argument)
Add the event name to make it clear to which event the filter
failed to apply:
Error: Failed to set filter "foo" on event sched:sg_lb_stats: 22: Invalid argument
To test it use something like:
# perf record -e sched:sched_switch -e sched:*fork --filter parent_pid==1 -e sched:*wait* --filter bla usleep 1
Error: failed to set filter "bla" on event sched:sched_stat_iowait with 22 (Invalid argument)
#
Based-on-a-patch-by: David Ahern <dsahern@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-d7gq2fjvaecozp9o2i0siifu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If /proc/sys/kernel/perf_event_mlock_kb is not (power of 2 + PAGE_SIZE_in_kb)
and we let the perf tools do mmap length autosizing based on that, then, for
non-CAP_IPC_LOCK users when /proc/sys/kernel/perf_event_paranoid is > -1, then
we get an -EINVAL that ends up in:
[acme@ssdandy linux]$ trace usleep 1
Invalid argument
[acme@ssdandy linux]$ perf record usleep 1
failed to mmap with 22 (Invalid argument)
After this fix:
[acme@ssdandy linux]$ trace usleep 1
<SNIP>
0.806 ( 0.006 ms): munmap(addr: 0x7f7e4740a000, len: 66467) = 0
0.869 ( 0.002 ms): brk( ) = 0x7bb000
0.873 ( 0.003 ms): brk(brk: 0x7dc000 ) = 0x7dc000
0.877 ( 0.001 ms): brk( ) = 0x7dc000
0.953 ( 0.058 ms): nanosleep(rqtp: 0x7fff26ab9420 ) = 0
0.959 ( 0.000 ms): exit_group(
[acme@ssdandy linux]$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data (~759 samples) ]
[acme@ssdandy linux]$
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: 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-6p6l5ou6jev6o7ymc4nn1n2a@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Considering the per user locked pages limit, improve the message when a
user uses multiple simultaneous perf mmap calls:
When the request is more than the current maximum:
[acme@ssdandy linux]$ trace -m 128 usleep 1
Error: Operation not permitted.
Hint: Check /proc/sys/kernel/perf_event_mlock_kb (516 kB) setting.
Hint: Tried using 516 kB.
Hint: Try 'sudo sh -c "echo 1032 > /proc/sys/kernel/perf_event_mlock_kb"', or
Hint: Try using a smaller -m/--mmap-pages value.
[acme@ssdandy linux]$
And when the limit is less than that:
[acme@ssdandy linux]$ trace -m 512 usleep 1
Error: Operation not permitted.
Hint: Check /proc/sys/kernel/perf_event_mlock_kb (2056 kB) setting.
Hint: Tried using 2052 kB.
Hint: Try using a smaller -m/--mmap-pages value.
[acme@ssdandy linux]$
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: 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-yqdie3c8qvdgenwleri267d4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When failing due to asking for a number of mmap pages that is more than
the max, it was suggesting that an even bigger number of mmap pages
should be specified, doh, au contraire!
Before:
[acme@ssdandy linux]$ trace -m 128 usleep 1
Error: Operation not permitted.
Hint: Check /proc/sys/kernel/perf_event_mlock_kb (516 kB) setting.
Hint: Tried using 516 kB.
Hint: Try using a bigger -m/--mmap-pages value.
[acme@ssdandy linux]$
After:
[acme@ssdandy linux]$ trace -m 128 usleep 1
Error: Operation not permitted.
Hint: Check /proc/sys/kernel/perf_event_mlock_kb (516 kB) setting.
Hint: Tried using 516 kB.
Hint: Try using a smaller -m/--mmap-pages value.
[acme@ssdandy linux]$
And to (really) clarify what happens above, when what the user requests
is <= max and even then it fails, a changeset is being made to tell that
this is a per user limit, not per process (in the above example there
was another 'perf trace' running for this user, which was using all the
pages it could use).
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: 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-8qope8lxb898narnq5kmu2gf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
