Pull perf/core improvements and fixes Arnaldo Carvalho de Melo:
User visible changes:
- Fix 'perf stat' bug in handling events in error state (Stephane Eranian)
Documentation changes:
- Add usage of --no-syscalls in 'perf trace' man page (Ravi Bangoria)
Infrastructure changes:
- Pass PYTHON config to feature detection (David Carrillo-Cisneros)
- Disable JVMTI if no ELF support available (David Carrillo-Cisneros)
- Fix feature detection redefinion of build flags (David Carrillo-Cisneros)
- Hint missing file when tool tips fail to load (David Carrillo-Cisneros)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Spurious NMIs will be observed with the following command:
while :; do
perf record -bae "cpu/umask=0x01,event=0xcd,ldlat=0x80/pp"
-e "cpu/umask=0x03,event=0x0/"
-e "cpu/umask=0x02,event=0x0/"
-e cycles,branches,cache-misses
-e cache-references -- sleep 10
done
The bug was introduced by commit:
8077eca079 ("perf/x86/pebs: Add workaround for broken OVFL status on HSW+")
That commit clears the status bits for the counters used for PEBS
events, by masking the whole 64 bits pebs_enabled. However, only the
low 32 bits of both status and pebs_enabled are reserved for PEBS-able
counters.
For status bits 32-34 are fixed counter overflow bits. For
pebs_enabled bits 32-34 are for PEBS Load Latency.
In the test case, the PEBS Load Latency event and fixed counter event
could overflow at the same time. The fixed counter overflow bit will
be cleared by mistake. Once it is cleared, the fixed counter overflow
never be processed, which finally trigger spurious NMI.
Correct the PEBS enabled mask by ignoring the non-PEBS bits.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 8077eca079 ("perf/x86/pebs: Add workaround for broken OVFL status on HSW+")
Link: http://lkml.kernel.org/r/1491333246-3965-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf trace supports --no-syscalls option but it's not listed in the man
page. (Though, I see an example using --no-syscalls in EXAMPLES
section.)
Committer note:
The --no-syscalls option tells 'perf trace' not to automagically ask for
raw_syscalls:sys_{enter,exit} to then format it in a strace like way.
This become more used as 'perf trace' got support for arbitrary events,
such as tracepoints, so more and more we use:
# perf trace --no-syscalls -e nmi:*
0.000 nmi:nmi_handler:perf_event_nmi_handler() delta_ns: 36649 handled: 1)
0.019 nmi:nmi_handler:nmi_cpu_backtrace_handler() delta_ns: 2907 handled: 0)
0.676 nmi:nmi_handler:perf_event_nmi_handler() delta_ns: 9401 handled: 1)
0.680 nmi:nmi_handler:nmi_cpu_backtrace_handler() delta_ns: 288 handled: 0)
0.701 nmi:nmi_handler:perf_event_nmi_handler() delta_ns: 4977 handled: 1)
0.703 nmi:nmi_handler:nmi_cpu_backtrace_handler() delta_ns: 67 handled: 0)
0.736 nmi:nmi_handler:perf_event_nmi_handler() delta_ns: 8549 handled: 1)
^C#
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexis Berlemont <alexis.berlemont@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1492063332-5745-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf/core improvements and fixes:
User visible changes:
- Support s390 jump instructions in perf annotate (Christian Borntraeger)
- When failing to setup multiple events (e.g. '-e irq_vectors:*'), state
which one caused the failure (Yao Jin)
- Various fixes for pipe mode, where the output of 'perf record' is
written to stdout instead of to a perf.data file, fixing workloads
such as: (David Carrillo-Cisneros)
$ perf record -o - noploop | perf inject -b > perf.data
$ perf record -o - noploop | perf annotate
Infrastructure changes:
- Simplify ltrim() implementation (Arnaldo Carvalho de Melo)
- Use ltrim() and rtrim() in places where ad-hoc equivalents were being
used (Taeung Song)
Conflicts:
tools/perf/util/annotate.c
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull 'perf annotate' fix for s390:
- The move to support cross arch annotation introduced per arch
initialization requirements, fullfill them for s/390 (Christian Borntraeger)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf annotate did not get some love for pipe-mode, and did not have
.attr and .buil_id setup (while record and inject did. Fix that.
It can easily be reproduced by:
perf record -o - noploop | perf annotate
that in my system shows:
0xd8 [0x28]: failed to process type: 9
Committer Testing:
Before:
$ perf record -o - stress -t 2 -c 2 | perf annotate --stdio
stress: info: [11060] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
0x4470 [0x28]: failed to process type: 9
$ stress: info: [11060] successful run completed in 2s
$
After:
$ perf record -o - stress -t 2 -c 2 | perf annotate --stdio
stress: info: [11871] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
stress: info: [11871] successful run completed in 2s
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.000 MB - ]
no symbols found in /usr/bin/stress, maybe install a debug package?
Percent | Source code & Disassembly of libc-2.24.so for cycles:uhH (6117 samples)
---------------------------------------------------------------------------------------
:
: Disassembly of section .text:
:
: 000000000003b050 <random_r>:
: __random_r():
10.56 : 3b050: test %rdi,%rdi
0.00 : 3b053: je 3b0d0 <random_r+0x80>
0.34 : 3b055: test %rsi,%rsi
0.00 : 3b058: je 3b0d0 <random_r+0x80>
0.46 : 3b05a: mov 0x18(%rdi),%eax
12.44 : 3b05d: mov 0x10(%rdi),%r8
0.18 : 3b061: test %eax,%eax
0.00 : 3b063: je 3b0b0 <random_r+0x60>
<SNIP>
Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170410201432.24807-5-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
__perf_session__process_pipe_events reuses the same memory buffer to
process all events in the pipe.
When reordering is needed (e.g. -b option), events are not immediately
flushed, but kept around until reordering is possible, causing
memory corruption.
The problem is usually observed by a "Unknown sample error" output. It
can easily be reproduced by:
perf record -o - noploop | perf inject -b > output
Committer testing:
Before:
$ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
stress: info: [8297] successful run completed in 2s
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.000 MB - ]
Warning:
Found 1 unknown events!
Is this an older tool processing a perf.data file generated by a more recent tool?
If that is not the case, consider reporting to linux-kernel@vger.kernel.org.
$
After:
$ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
stress: info: [9027] successful run completed in 2s
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.000 MB - ]
no symbols found in /usr/bin/stress, maybe install a debug package?
no symbols found in /usr/bin/stress, maybe install a debug package?
$
Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We don't need to use strlen(), a var, or check for the end explicitely,
isspace('\0') is false:
[acme@jouet c]$ cat ltrim.c
#include <ctype.h>
#include <stdio.h>
static char *ltrim(char *s)
{
while (isspace(*s))
++s;
return s;
}
int main(void)
{
printf("ltrim(\"\")='%s'\n", ltrim(""));
return 0;
}
[acme@jouet c]$ ./ltrim
ltrim("")=''
[acme@jouet c]$
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: http://lkml.kernel.org/n/tip-w3nk0x3pai2vojk2ab6kdvaw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The kernel has a special check for a specific irq_vectors trace event.
TRACE_EVENT_PERF_PERM(irq_work_exit,
is_sampling_event(p_event) ? -EPERM : 0);
The perf-record fails for this irq_vectors event when it is present,
like when using a wildcard:
root@skl:/tmp# perf record -a -e irq_vectors:* sleep 2
Error:
You may not have permission to collect system-wide stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_SYS_ADMIN).
The current value is 2:
-1: Allow use of (almost) all events by all users
>= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
>= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
To make this setting permanent, edit /etc/sysctl.conf too, e.g.:
kernel.perf_event_paranoid = -1
This patch prints out the exact sub event that failed with EPERM for
wildcards to help in understanding what went wrong when this event is
present:
After the patch:
root@skl:/tmp# perf record -a -e irq_vectors:* sleep 2
Error:
No permission to enable irq_vectors:irq_work_exit event.
You may not have permission to collect system-wide stats.
......
Committer notes:
So we have a lot of irq_vectors events:
[root@jouet ~]# perf list irq_vectors:*
List of pre-defined events (to be used in -e):
irq_vectors:call_function_entry [Tracepoint event]
irq_vectors:call_function_exit [Tracepoint event]
irq_vectors:call_function_single_entry [Tracepoint event]
irq_vectors:call_function_single_exit [Tracepoint event]
irq_vectors:deferred_error_apic_entry [Tracepoint event]
irq_vectors:deferred_error_apic_exit [Tracepoint event]
irq_vectors:error_apic_entry [Tracepoint event]
irq_vectors:error_apic_exit [Tracepoint event]
irq_vectors:irq_work_entry [Tracepoint event]
irq_vectors:irq_work_exit [Tracepoint event]
irq_vectors:local_timer_entry [Tracepoint event]
irq_vectors:local_timer_exit [Tracepoint event]
irq_vectors:reschedule_entry [Tracepoint event]
irq_vectors:reschedule_exit [Tracepoint event]
irq_vectors:spurious_apic_entry [Tracepoint event]
irq_vectors:spurious_apic_exit [Tracepoint event]
irq_vectors:thermal_apic_entry [Tracepoint event]
irq_vectors:thermal_apic_exit [Tracepoint event]
irq_vectors:threshold_apic_entry [Tracepoint event]
irq_vectors:threshold_apic_exit [Tracepoint event]
irq_vectors:x86_platform_ipi_entry [Tracepoint event]
irq_vectors:x86_platform_ipi_exit [Tracepoint event]
#
And some may be sampled:
[root@jouet ~]# perf record -e irq_vectors:local* sleep 20s
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.020 MB perf.data (2 samples) ]
[root@jouet ~]# perf report -D | egrep 'stats:|events:'
Aggregated stats:
TOTAL events: 155
MMAP events: 144
COMM events: 2
EXIT events: 1
SAMPLE events: 2
MMAP2 events: 4
FINISHED_ROUND events: 1
TIME_CONV events: 1
irq_vectors:local_timer_entry stats:
TOTAL events: 1
SAMPLE events: 1
irq_vectors:local_timer_exit stats:
TOTAL events: 1
SAMPLE events: 1
[root@jouet ~]#
But, as shown in the tracepoint definition at the start of this message,
some, like "irq_vectors:irq_work_exit", may not be sampled, just counted,
i.e. if we try to sample, as when using 'perf record', we get an error:
[root@jouet ~]# perf record -e irq_vectors:irq_work_exit
Error:
You may not have permission to collect system-wide stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
<SNIP>
The error message is misleading, this patch will help in pointing out
what is the event causing such an error, but the error message needs
improvement, i.e. we need to figure out a way to check if a tracepoint
is counting only, like this one, when all we can do is to count it with
'perf stat', at most printing the delta using interval printing, as in:
[root@jouet ~]# perf stat -I 5000 -e irq_vectors:irq_work_*
# time counts unit events
5.000168871 0 irq_vectors:irq_work_entry
5.000168871 0 irq_vectors:irq_work_exit
10.000676730 0 irq_vectors:irq_work_entry
10.000676730 0 irq_vectors:irq_work_exit
15.001122415 0 irq_vectors:irq_work_entry
15.001122415 0 irq_vectors:irq_work_exit
20.001298051 0 irq_vectors:irq_work_entry
20.001298051 0 irq_vectors:irq_work_exit
25.001485020 1 irq_vectors:irq_work_entry
25.001485020 1 irq_vectors:irq_work_exit
30.001658706 0 irq_vectors:irq_work_entry
30.001658706 0 irq_vectors:irq_work_exit
^C 32.045711878 0 irq_vectors:irq_work_entry
32.045711878 0 irq_vectors:irq_work_exit
[root@jouet ~]#
But at least, when we use a wildcard, this patch helps a bit.
Signed-off-by: Yao Jin <yao.jin@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1491566932-503-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
