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>
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>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Account thread wait time (off CPU time) separately: sleep, iowait and
preempt, based on the prev_state of the last event, show the breakdown
when using "perf sched timehist --state" (Namhyumg Kim)
Infrastructure changes:
- Factor out PMU scale conversion code (Andi Kleen)
- Remove unnecessary feature-dwarf warning (David Carrillo-Cisneros)
- Add missing member name in OPT_() macros (Soramichi AKIYAMA)
- Move variables referenced in libperf.a object files from perf's main()
file, so that other tools can use libperf.a with a different main()
(Soramichi AKIYAMA)
Documentation changes:
- Fix 'perf script' man page about --dump-raw-trace option (Michael Petlan)
- Also allow forcing reading of non-root owned files by root in 'perf
script' (Yannick Brosseau)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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>
Improve __kernel_text_address()/kernel_text_address() to return
true if the given address is on a kprobe's instruction slot
trampoline.
This can help stacktraces to determine the address is on a
text area or not.
To implement this atomically in is_kprobe_*_slot(), also change
the insn_cache page list to an RCU list.
This changes timings a bit (it delays page freeing to the RCU garbage
collection phase), but none of that is in the hot path.
Note: this change can add small overhead to stack unwinders because
it adds 2 additional checks to __kernel_text_address(). However, the
impact should be very small, because kprobe_insn_pages list has 1 entry
per 256 probes(on x86, on arm/arm64 it will be 1024 probes),
and kprobe_optinsn_pages has 1 entry per 32 probes(on x86).
In most use cases, the number of kprobe events may be less
than 20, which means that is_kprobe_*_slot() will check just one entry.
Tested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/148388747896.6869.6354262871751682264.stgit@devbox
[ Improved the changelog and coding style. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Add more triggers to switch the output file (perf.data.TIMESTAMP).
Now, in addition to switching to a different output file when
receiving a SIGUSR2, one can also specify file size and time based
triggers:
perf record -a --switch-output=signal
is equivalent to what we had before:
perf record -a --switch-output
While we can also ask for the file to be "sliced" by size, taking
into account that that will happen only when we get woken up by
the kernel, i.e. one has to take into account the --mmap-pages (the
size of the perf mmap ring buffer):
perf record -a --switch-output=2G
will break the perf.data output into multiple files limited to 2GB
of samples, right when generating the output.
For time based samples, alert() will be used, so to have 1 minute
limited perf.data output files:
perf record -a --switch-output=1m
(Jiri Olsa)
- Remove the need to use -e only for syscalls and --event only for
tracepoints/HW/SW/etc events, i.e. now one can use:
perf trace -e nanosleep,futex,sched:sched_switch ./workload
or:
perf trace --event nanosleep,futex,sched:sched_switch ./workload
And have it tracing raw_syscalls:sys_{enter,exit} for the nanosleep
and futex syscalls, formatting those as strace does while also
tracing sched:sched_switch, ordering it all into one strace like
output.
Using '!' as the first character in the -e/--event argument remains
a way to negate the list of syscalls, i.e. all syscalls except for
the ones specified, doesn't affect the other kinds of events.
E.g:
[root@jouet ~] # perf trace -e sched:sched_switch,nanosleep usleep 1
0.000 ( 0.028 ms): usleep/28150 nanosleep(rqtp: 0x7ffe4201b9f0) ...
0.028 ( ): sched:sched_switch:usleep:28150 [120] S ==> swapper/0:0 [120])
0.000 ( 0.065 ms): usleep/28150 ... [continued]: nanosleep()) = 0
[root@jouet ~]#
(Arnaldo Carvalho de Melo)
- 'perf kallsyms' toy tool to look for extended symbol information on
the running kernel and demonstrate the machine/thread/symbol APIs for
use in other tools, such as 'perf probe' (Arnaldo Carvalho de Melo)
Infrastructure improvements:
- Add missing linux/kernel.h include to subcmd.h (Arnaldo Carvalho de Melo)
tools: Sync x86's vmx.h with the kernel
- Create libdir directory before installing libperf-jvmti.so (Laura Abbott)
- Fix typo in perf_evlist__start_workload() (Soramichi Akiyama)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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>
Joe Stringer
Markus Elfring
He Kuang
Jiri Olsa
Matija Glavinic Pecotic
Ingo Molnar
Soramichi AKIYAMA
Namhyung Kim
Yannick Brosseau
Michael Petlan
David Carrillo-Cisneros
Andi Kleen
Masami Hiramatsu
Arnaldo Carvalho de Melo