Add new APIs to pin a BPF program (or specific instances) to the
filesystem. The user can specify the path full path within a BPF
filesystem to pin the program.
bpf_program__pin_instance(prog, path, n) will pin the nth instance of
'prog' to the specified path.
bpf_program__pin(prog, path) will create the directory 'path' (if it
does not exist) and pin each instance within that directory. For
instance, path/0, path/1, path/2.
Committer notes:
- Add missing headers for mkdir()
- Check strdup() for failure
- Check snprintf >= size, not >, as == also means truncated, see 'man
snprintf', return value.
- Conditionally define BPF_FS_MAGIC, as it isn't in magic.h in older
systems and we're not yet having a tools/include/uapi/linux/magic.h
copy.
- Do not include linux/magic.h, not present in older distros.
Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-2-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The following upstream headers were updated:
- The x86 cpufeatures.h file picked up a couple of new feature entries
- The PowerPC and ARM KVM headers picked up new features
None of which requires changes to perf tooling, so refresh the tooling copy.
Solves these build time warnings:
Warning: arch/x86/include/asm/cpufeatures.h differs from kernel
Warning: arch/powerpc/include/uapi/asm/kvm.h differs from kernel
Warning: arch/arm/include/uapi/asm/kvm.h differs from kernel
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170130081131.GA8322@gmail.com
[ resync tools/arch/x86/include/asm/cpufeatures.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Previously these were being ignored, sometimes silently.
Stop doing that, emitting debug messages and handling the errors.
Testing it:
$ cat ~/.perfconfig
cat: /home/acme/.perfconfig: No such file or directory
$ perf stat -e cycles usleep 1
Performance counter stats for 'usleep 1':
938,996 cycles:u
0.003813731 seconds time elapsed
$ perf top --stdio
Error:
You may not have permission to collect system-wide stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
<SNIP>
[ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
[acme@jouet linux]$ perf report --stdio
# To display the perf.data header info, please use --header/--header-only options.
# Overhead Command Shared Object Symbol
# ........ ....... ................. .........................
71.77% usleep libc-2.24.so [.] _dl_addr
27.07% usleep ld-2.24.so [.] _dl_next_ld_env_entry
1.13% usleep [kernel.kallsyms] [k] page_fault
$
$ touch ~/.perfconfig
$ ls -la ~/.perfconfig
-rw-rw-r--. 1 acme acme 0 Jan 27 12:14 /home/acme/.perfconfig
$
$ perf stat -e instructions usleep 1
Performance counter stats for 'usleep 1':
244,610 instructions:u
0.000805383 seconds time elapsed
$
[root@jouet ~]# chown acme.acme ~/.perfconfig
[root@jouet ~]# perf stat -e cycles usleep 1
Warning: File /root/.perfconfig not owned by current user or root, ignoring it.
Performance counter stats for 'usleep 1':
937,615 cycles
0.000836931 seconds time elapsed
#
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-j2rq96so6xdqlr8p8rd6a3jx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
While propagating the errors from perf_config(), which were being
completely ignored, everything stopped working for people without a
~/.perfconfig file, because the perf_config_set__init() was considering
an error not to have a .perfconfig file, duh, fix it by checking the
errno after the failed stat() call.
It should also not return an error when it says it is ignoring the file,
and also a empty file should not return an error either.
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: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 8beeb00f2c ("perf config: Use new perf_config_set__init() to initialize config set")
Link: http://lkml.kernel.org/n/tip-ygpbab3apbs6l8wr97xedwks@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When doing a kernel build with 'make -s', everything is silenced except
the objtool build. That's because the tools tree support for silent
builds is some combination of missing and broken.
Three changes are needed to fix it:
- Makefile: propagate '-s' to the sub-make's MAKEFLAGS variable so the
tools Makefiles can see it.
- tools/scripts/Makefile.include: fix the tools Makefiles' ability to
recognize '-s'. The MAKE_VERSION and MAKEFLAGS checks are copied from
the top-level Makefile. This silences the "DESCEND objtool" message.
- tools/build/Makefile.build: add support to the tools Build files for
recognizing '-s'. Again the MAKE_VERSION and MAKEFLAGS checks are
copied from the top-level Makefile. This silences all the object
compile/link messages.
Reported-and-Tested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michal Marek <mmarek@suse.com>
Link: http://lkml.kernel.org/r/e8967562ef640c3ae9a76da4ae0f4e47df737c34.1484799200.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull the latest perf/core updates from Arnaldo Carvalho de Melo:
New features:
- Introduce 'perf ftrace' a perf front end to the kernel's ftrace
function and function_graph tracer, defaulting to the "function_graph"
tracer, more work will be done in reviving this effort, forward porting
it from its initial patch submission (Namhyung Kim)
- Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)
Fixes:
- Fix wrong register name for arm64, used in 'perf probe' (He Kuang)
- Fix map offsets in relocation in libbpf (Joe Stringer)
- Fix looking up dwarf unwind stack info (Matija Glavinic Pecotic)
Infrastructure changes:
- libbpf prog functions sync with what is exported via uapi (Joe Stringer)
Trivial changes:
- Remove unnecessary checks and assignments in 'perf probe's
try_to_find_absolute_address() (Markus Elfring)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 4708bbda5c ("tools lib bpf: Fix maps resolution") attempted to
fix map resolution by identifying the number of symbols that point to
maps, and using this number to resolve each of the maps.
However, during relocation the original definition of the map size was
still in use. For up to two maps, the calculation was correct if there
was a small difference in size between the map definition in libbpf and
the one that the client library uses. However if the difference was
large, particularly if more than two maps were used in the BPF program,
the relocation would fail.
For example, when using a map definition with size 28, with three maps,
map relocation would count:
(sym_offset / sizeof(struct bpf_map_def) => map_idx)
(0 / 16 => 0), ie map_idx = 0
(28 / 16 => 1), ie map_idx = 1
(56 / 16 => 3), ie map_idx = 3
So, libbpf reports:
libbpf: bpf relocation: map_idx 3 large than 2
Fix map relocation by checking the exact offset of maps when doing
relocation.
Signed-off-by: Joe Stringer <joe@ovn.org>
[Allow different map size in an object]
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: netdev@vger.kernel.org
Fixes: 4708bbda5c ("tools lib bpf: Fix maps resolution")
Link: http://lkml.kernel.org/r/20170123011128.26534-2-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull virtio/vhost fixes from Michael Tsirkin:
"Random fixes and cleanups that accumulated over the time"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio/s390: virtio: constify virtio_config_ops structures
virtio/s390: add missing \n to end of dev_err message
virtio/s390: support READ_STATUS command for virtio-ccw
tools/virtio/ringtest: tweaks for s390
tools/virtio/ringtest: fix run-on-all.sh for offline cpus
virtio_console: fix a crash in config_work_handler
vhost/scsi: silence uninitialized variable warning
vhost: scsi: constify target_core_fabric_ops structures
Pull powerpc fixes from Michael Ellerman:
"Two fixes for fallout from the hugetlb changes we merged this cycle.
Ten other fixes, four only affect Power9, and the rest are a bit of a
mixture though nothing terrible.
Thanks to: Aneesh Kumar K.V, Anton Blanchard, Benjamin Herrenschmidt,
Dave Martin, Gavin Shan, Madhavan Srinivasan, Nicholas Piggin, Reza
Arbab"
* tag 'powerpc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc: Ignore reserved field in DCSR and PVR reads and writes
powerpc/ptrace: Preserve previous TM fprs/vsrs on short regset write
powerpc/ptrace: Preserve previous fprs/vsrs on short regset write
powerpc/perf: Use MSR to report privilege level on P9 DD1
selftest/powerpc: Wrong PMC initialized in pmc56_overflow test
powerpc/eeh: Enable IO path on permanent error
powerpc/perf: Fix PM_BRU_CMPL event code for power9
powerpc/mm: Fix little-endian 4K hugetlb
powerpc/mm/hugetlb: Don't panic when we don't find the default huge page size
powerpc: Fix pgtable pmd cache init
powerpc/icp-opal: Fix missing KVM case and harden replay
powerpc/mm: Fix memory hotplug BUG() on radix
Since ef1b144d ("tools/virtio/ringtest: fix run-on-all.sh to work
without /dev/cpu") run-on-all.sh uses seq 0 $HOST_AFFINITY as the list
of ids of the CPUs to run the command on (assuming ids of online CPUs
are consecutive and start from 0), where $HOST_AFFINITY is the highest
CPU id in the system previously determined using lscpu. This can fail
on systems with offline CPUs.
Instead let's use lscpu to determine the list of online CPUs.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Fixes: ef1b144d ("tools/virtio/ringtest: fix run-on-all.sh to work without
/dev/cpu")
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Using perf with call graph method dwarf fails to provide backtrace
support for stripped binary even though .gnu_debuglink points to *.dbg
flavor with properly populated debug symbols.
Problem is reproduced on ARM (v7, v8), kernels 3.14.y, 4.4.y and
4.10.rc3. Perf is configured with libunwind, and unwind dwarf support
[1]. Test code (stress_bt.c) can be found on [2].
Running (explicitly disable other unwinding methods):
$ gcc -g -o stress_bt -fomit-frame-pointer -fno-unwind-tables \
-fno-asynchronous-unwind-tables stress_bt.c
$ perf record -N --call-graph dwarf ./stress_bt
$ perf report
results in properly generated call graph. Stripping the binary and running
it results with missing call graph. Expected result is to have call graph:
$ gcc -g -o stress_bt -fomit-frame-pointer -fno-unwind-tables \
-fno-asynchronous-unwind-tables stress_bt.c
$ objcopy --only-keep-debug stress_bt stress_bt.dbg
$ objcopy --strip-debug stress_bt
$ objcopy --add-gnu-debuglink=stress_bt.dbg stress_bt
$ perf record -N --call-graph dwarf ./stress_bt
$ perf report
Problem is that perf doesn't try to read symbols pointed by gnu
debuglink. Patch adds checking, and reading of the symbols from
debuglink and symsrc. Order of the check is to first check within dso,
then check whether symsrc is defined and try to read from it. Finally,
debuglink is checked. Default locations of debug files are discussed in
[3] and [4]. Comments on RFC are on [5].
[1] https://wiki.linaro.org/LEG/Engineering/TOOLS/perf-callstack-unwinding
[2] [1]#Backtrace_stress_application
[3] https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
[4] https://sourceware.org/binutils/docs/binutils/objcopy.html
[5] https://lkml.org/lkml/2016/8/22/473
Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/d309d40a-463f-482b-68e1-1465326efdc1@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Test uses PMC2 to count the event. But PMC1 is being initialized.
Patch to fix it.
Fixes: 3752e453f6 ('selftests/powerpc: Add tests of PMU EBBs')
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The use_browser and perf_version_string variables are both declared in
perf.c but they are also referenced by other functions of libperf.a.
Therefore a user linking an own main() with libperf.a must declare those
two variables in their files even if the files never use the browser or
the version information.
This patch fixes this issue by moving use_browser and
perf_version_string out of perf.c to some other files.
Signed-off-by: Soramichi Akiyama <akiyama@m.soramichi.jp>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170117002237.c1aec0ce3b4d675dca018deb@m.soramichi.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The --state option is to show task state when switched out. The state
is printed as a single character like in the /proc but I added 'I' for
idle state rather than 'R'.
$ perf sched timehist --state | head
Samples do not have callchains.
time cpu task name wait time sch delay run time state
[tid/pid] (msec) (msec) (msec)
-------- --- ----------------------- -------- ------------------ -----
1.753791 [3] <idle> 0.000 0.000 0.000 I
1.753834 [1] perf[27469] 0.000 0.000 0.000 S
1.753904 [3] perf[27470] 0.000 0.006 0.112 S
1.753914 [1] <idle> 0.000 0.000 0.079 I
1.753915 [3] migration/3[23] 0.000 0.002 0.011 S
1.754287 [2] <idle> 0.000 0.000 0.000 I
1.754335 [2] transmission[1773/1739] 0.000 0.004 0.047 S
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170113104523.31212-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to probe on gcc generated functions on modules. Since
probing on a module is based on its symbol name, it should
be adjusted on actual symbols.
E.g. without this fix, perf probe shows probe definition
on non-exist symbol as below.
$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range*
in_range.isra.12
$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
p:probe/in_range nf_nat:in_range+0
With this fix, perf probe correctly shows a probe on
gcc-generated symbol.
$ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
p:probe/in_range nf_nat:in_range.isra.12+0
This also fixes same problem on online module as below.
$ perf probe -m i915 -D assert_plane
p:probe/assert_plane i915:assert_plane.constprop.134+0
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to show correct locations for events on modules by relocating given
address instead of retrying after failure.
This happens when the module text size is big enough, bigger than
sh_addr, because the original code retries with given address + sh_addr
if it failed to find CU DIE at the given address.
Any address smaller than sh_addr always fails and it retries with the
correct address, but addresses bigger than sh_addr will get a CU DIE
which is on the given address (not adjusted by sh_addr).
In my environment(x86-64), the sh_addr of ".text" section is 0x10030.
Since i915 is a huge kernel module, we can see this issue as below.
$ grep "[Tt] .*\[i915\]" /proc/kallsyms | sort | head -n1
ffffffffc0270000 t i915_switcheroo_can_switch [i915]
ffffffffc0270000 + 0x10030 = ffffffffc0280030, so we'll check
symbols cross this boundary.
$ grep "[Tt] .*\[i915\]" /proc/kallsyms | grep -B1 ^ffffffffc028\
| head -n 2
ffffffffc027ff80 t haswell_init_clock_gating [i915]
ffffffffc0280110 t valleyview_init_clock_gating [i915]
So setup probes on both function and see what happen.
$ sudo ./perf probe -m i915 -a haswell_init_clock_gating \
-a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)
You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
$ sudo ./perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on i915_vga_set_decode:4@gpu/drm/i915/i915_drv.c in i915)
As you can see, haswell_init_clock_gating is correctly shown,
but valleyview_init_clock_gating is not.
With this patch, both events are shown correctly.
$ sudo ./perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
Committer notes:
In my case:
# perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)
You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
# perf probe -l
probe:haswell_init_clock_gating (on i915_getparam+432@gpu/drm/i915/i915_drv.c in i915)
probe:valleyview_init_clock_gating (on __i915_printk+240@gpu/drm/i915/i915_drv.c in i915)
#
# readelf -SW /lib/modules/4.9.0+/build/vmlinux | egrep -w '.text|Name'
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 1] .text PROGBITS ffffffff81000000 200000 822fd3 00 AX 0 0 4096
#
So both are b0rked, now with the fix:
# perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
Added new events:
probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)
You can now use it in all perf tools, such as:
perf record -e probe:valleyview_init_clock_gating -aR sleep 1
# perf probe -l
probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
#
Both looks correct.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411436777.9978.1440275861947194930.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf fixes from Ingo Molnar:
"Misc race fixes uncovered by fuzzing efforts, a Sparse fix, two PMU
driver fixes, plus miscellanous tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Reject non sampling events with precise_ip
perf/x86/intel: Account interrupts for PEBS errors
perf/core: Fix concurrent sys_perf_event_open() vs. 'move_group' race
perf/core: Fix sys_perf_event_open() vs. hotplug
perf/x86/intel: Use ULL constant to prevent undefined shift behaviour
perf/x86/intel/uncore: Fix hardcoded socket 0 assumption in the Haswell init code
perf/x86: Set pmu->module in Intel PMU modules
perf probe: Fix to probe on gcc generated symbols for offline kernel
perf probe: Fix --funcs to show correct symbols for offline module
perf symbols: Robustify reading of build-id from sysfs
perf tools: Install tools/lib/traceevent plugins with install-bin
tools lib traceevent: Fix prev/next_prio for deadline tasks
perf record: Fix --switch-output documentation and comment
perf record: Make __record_options static
tools lib subcmd: Add OPT_STRING_OPTARG_SET option
perf probe: Fix to get correct modname from elf header
samples/bpf trace_output_user: Remove duplicate sys/ioctl.h include
samples/bpf sock_example: Avoid getting ethhdr from two includes
perf sched timehist: Show total scheduling time
To pick the changes from:
1b07304c58 ("KVM: nVMX: support descriptor table exits")
That adds entries to VMX_EXIT_REASONS, that is used by
tools/perf/arch/x86/util/kvm-stat.c.
This also picks the changes in:
1dc35dacc1 ("KVM: nVMX: check host CR3 on vmentry and vmexit")
But these are not used in 'perf kvm stat', do it just to silence the
kernel/tools file cache coherency detector:
$ make -C tools/perf
make: Entering directory '/home/acme/git/linux/tools/perf'
BUILD: Doing 'make -j4' parallel build
Warning: arch/x86/include/uapi/asm/vmx.h differs from kernel
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ladi Prosek <lprosek@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-56uowkk8t5zje49a42asffcy@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It's now possible to specify the threshold time for perf.data like:
$ perf record --switch-output=30s ...
Once it's reached, the current data are dumped in to the
perf.data.<timestamp> file and session does on.
$ perf record --switch-output=30s ...
[ perf record: dump data: Woken up 44 times ]
[ perf record: Dump perf.data.2017010213043746 ]
...
The time is expected to be a number with appended unit
character - s/m/h/d.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1483955520-29063-7-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
