It is sometimes useful to generate a snapshot when perf record exits;
I've been using a wrapper script around the workload that would do a
killall -USR2 perf when the workload exits.
This patch makes it easier and also works when perf record is attached
to a pre-existing task. A new snapshot option 'e' can be specified in
-S to enable this behavior:
root@elsewhere:~# perf record -e intel_pt// -Se sleep 1
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.085 MB perf.data ]
Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190806144101.62892-1-alexander.shishkin@linux.intel.com
[ Fixed up !HAVE_AUXTRACE_SUPPORT build in builtin-record.c, adding 2 missing __maybe_unused ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add utilities to help checking capabilities of the running procss. Make
perf link with libcap, if it is available. If no libcap-dev[el],
fallback to the geteuid() == 0 test used before.
Committer notes:
$ perf test python
18: 'import perf' in python : FAILED!
$ perf test -v python
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
18: 'import perf' in python :
--- start ---
test child forked, pid 23288
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: /tmp/build/perf/python/perf.so: undefined symbol: cap_get_flag
test child finished with -1
---- end ----
'import perf' in python: FAILED!
$
This happens because differently from the perf binary generated with
this patch applied:
$ ldd /tmp/build/perf/perf | grep libcap
libcap.so.2 => /lib64/libcap.so.2 (0x00007f724a4ef000)
$
The python binding isn't linking with libcap:
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$
So add 'cap' to the 'extra_libraries' variable in
tools/perf/util/setup.py, and rebuild:
$ perf test python
18: 'import perf' in python : Ok
$
If we explicitely disable libcap it also continues to work:
$ make NO_LIBCAP=1 -C tools/perf O=/tmp/build/perf install-bin
$ ldd /tmp/build/perf/perf | grep libcap
$ ldd /tmp/build/perf/python/perf.so | grep libcap
$ perf test python
18: 'import perf' in python : Ok
$
Signed-off-by: Igor Lubashev <ilubashe@akamai.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
[ split from a larger patch ]
Link: http://lkml.kernel.org/r/8a1e76cf5c7c9796d0d4d240fbaa85305298aafa.1565188228.git.ilubashe@akamai.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When he have an event group we have multiple struct hist instances, one
per evsel, and in each of these hists we may have hist_entries that
point to the same thing being observed, say a symbol, i.e. if we're
looking at instructions and cycles, then we'll have one hist_entry in
the "instructions" evsel and another in the "cycles" evsel.
We need to link those to then show one column for each. When we're
looking at some other pair of events, say instructions and cache misses,
we may have just the "instructions" hist entry and not one for "cache
misses", as instructions not necessarily generate cache misses, as the
logic expects one hist_entry per evsel, we end up adding "dummy"
hist_entries.
This is enough for 'perf report', that does this matching operation
(hists__match()) just once after processing all events, but for 'perf
top', we do this at each refresh, so we may finally find events matching
and then we need to trow away the dummies and link with the real events.
So if we find a match, traverse the link of matches and trow away
dummies for that hists.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-dwvtjqqifsbsczeb35q6mqkk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
'perf trace' reports the segmentation fault as below on Arm64:
# perf trace -e string -e augmented_raw_syscalls.c
LLVM: dumping tools/perf/examples/bpf/augmented_raw_syscalls.o
perf: Segmentation fault
Obtained 12 stack frames.
perf(sighandler_dump_stack+0x47) [0xaaaaac96ac87]
linux-vdso.so.1(+0x5b7) [0xffffadbeb5b7]
/lib/aarch64-linux-gnu/libc.so.6(strlen+0x10) [0xfffface7d5d0]
/lib/aarch64-linux-gnu/libc.so.6(_IO_vfprintf+0x1ac7) [0xfffface49f97]
/lib/aarch64-linux-gnu/libc.so.6(__vsnprintf_chk+0xc7) [0xffffacedfbe7]
perf(scnprintf+0x97) [0xaaaaac9ca3ff]
perf(+0x997bb) [0xaaaaac8e37bb]
perf(cmd_trace+0x28e7) [0xaaaaac8ec09f]
perf(+0xd4a13) [0xaaaaac91ea13]
perf(main+0x62f) [0xaaaaac8a147f]
/lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe3) [0xfffface22d23]
perf(+0x57723) [0xaaaaac8a1723]
Segmentation fault
This issue is introduced by commit 30a910d7d3 ("perf trace:
Preallocate the syscall table"), it allocates trace->syscalls.table[]
array and the element count is 'trace->sctbl->syscalls.nr_entries'; but
on Arm64, the system call number is not continuously used; e.g. the
syscall maximum id is 436 but the real entries is only 281.
So the table is allocated with 'nr_entries' as the element count, but it
accesses the table with the syscall id, which might be out of the bound
of the array and cause the segmentation fault.
This patch allocates trace->syscalls.table[] with the element count is
'trace->sctbl->syscalls.max_id + 1', this allows any id to access the
table without out of the bound.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: 30a910d7d3 ("perf trace: Preallocate the syscall table")
Link: http://lkml.kernel.org/r/20190809104752.27338-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When we have multiple events in a group we link hist_entries in the
non-leader evsel hists to the one in the leader that points to the same
sorting criteria, in hists__match().
For 'perf report' we do this just once and then print the results, but
for 'perf top' we need to look if this was already done in the previous
refresh of the screen, so check for that and don't try to link again.
This is part of having 'perf top' using the hists browser for showing
multiple events in multiple columns.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-iwvb37rgb7upswhruwpcdnhw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get the expected output we have to ignore whatever changes the user
has in its ~/.perfconfig file, so set PERF_CONFIG to /dev/null to
achieve that.
Before:
# egrep 'trace|show_' ~/.perfconfig
[trace]
show_zeros = yes
show_duration = no
show_timestamp = no
show_arg_names = no
show_prefix = yes
# echo $PERF_CONFIG
# perf test "trace + vfs_getname"
70: Check open filename arg using perf trace + vfs_getname: FAILED!
# export PERF_CONFIG=/dev/null
# perf test "trace + vfs_getname"
70: Check open filename arg using perf trace + vfs_getname: Ok
#
After:
# egrep 'trace|show_' ~/.perfconfig
[trace]
show_zeros = yes
show_duration = no
show_timestamp = no
show_arg_names = no
show_prefix = yes
# echo $PERF_CONFIG
# perf test "trace + vfs_getname"
70: Check open filename arg using perf trace + vfs_getname: Ok
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Link: https://lkml.kernel.org/n/tip-3up27pexg5i3exuzqrvt4m8u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We had this comment in Documentation/perf_counter/config.c, i.e. since
when we got this from the git sources, but never really did that
getenv("PERF_CONFIG"), do it now as I need to disable whatever
~/.perfconfig root has so that tests parsing tool output are done for
the expected default output or that we specify an alternate config file
that when read will make the tools produce expected output.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Fixes: 0780060124 ("perf_counter tools: add in basic glue from Git")
Link: https://lkml.kernel.org/n/tip-jo209zac9rut0dz1rqvbdlgm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get closer to upstream and check if we need to sync more UAPI
headers, pick up fixes for libbpf that prevent perf's container tests
from completing successfuly, etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull dax fixes from Dan Williams:
"A filesystem-dax and device-dax fix for v5.3.
The filesystem-dax fix is tagged for stable as the implementation has
been mistakenly throwing away all cow pages on any truncate or hole
punch operation as part of the solution to coordinate device-dma vs
truncate to dax pages.
The device-dax change fixes up a regression this cycle from the
introduction of a common 'internal per-cpu-ref' implementation.
Summary:
- Fix dax_layout_busy_page() to not discard private cow pages of
fs/dax private mappings.
- Update the memremap_pages core to properly cleanup on behalf of
internal reference-count users like device-dax"
* tag 'dax-fixes-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
mm/memremap: Fix reuse of pgmap instances with internal references
dax: dax_layout_busy_page() should not unmap cow pages
Pull NTB fix from Jon Mason:
"Bug fix for NTB MSI kernel compile warning"
* tag 'ntb-5.3-bugfixes' of git://github.com/jonmason/ntb:
NTB/msi: remove incorrect MODULE defines
Pull RISC-V updates from Paul Walmsley:
"A few minor RISC-V updates for v5.3-rc4:
- Remove __udivdi3() from the 32-bit Linux port, converting the only
upstream user to use do_div(), per Linux policy
- Convert the RISC-V standard clocksource away from per-cpu data
structures, since only one is used by Linux, even on a multi-CPU
system
- A set of DT binding updates that remove an obsolete text binding in
favor of a YAML binding, fix a bogus compatible string in the
schema (thus fixing a "make dtbs_check" warning), and clarifies the
future values expected in one of the RISC-V CPU properties"
* tag 'riscv/for-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
dt-bindings: riscv: fix the schema compatible string for the HiFive Unleashed board
dt-bindings: riscv: remove obsolete cpus.txt
RISC-V: Remove udivdi3
riscv: delay: use do_div() instead of __udivdi3()
dt-bindings: Update the riscv,isa string description
RISC-V: Remove per cpu clocksource
Pull x86 fixes from Thomas Gleixner:
"A few fixes for x86:
- Don't reset the carefully adjusted build flags for the purgatory
and remove the unwanted flags instead. The 'reset all' approach led
to build fails under certain circumstances.
- Unbreak CLANG build of the purgatory by avoiding the builtin
memcpy/memset implementations.
- Address missing prototype warnings by including the proper header
- Fix yet more fall-through issues"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/lib/cpu: Address missing prototypes warning
x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
x86/purgatory: Do not use __builtin_memcpy and __builtin_memset
x86: mtrr: cyrix: Mark expected switch fall-through
x86/ptrace: Mark expected switch fall-through
Adrian Hunter
Alexander Shishkin
Arnaldo Carvalho de Melo
Igor Lubashev
Leo Yan
Haiyan Song
Luke Mujica
Linus Torvalds