Storing data for VDSO shared object, because we need it for the post
unwind processing.
The VDSO shared object is same for all process on a running system, so
it makes no difference when we store it inside the tracer - perf.
When [vdso] map memory is hit, we retrieve [vdso] DSO image and store it
into temporary file.
During the build-id processing phase, the [vdso] DSO image is stored in
build-id db, and build-id reference is made inside perf.data. The
build-id vdso file object is called '[vdso]'. We don't use temporary
file name which gets removed when record is finished.
During report phase the vdso build-id object is treated as any other
build-id DSO object.
Adding following API for vdso object:
bool is_vdso_map(const char *filename)
- returns true if the filename matches vdso map name
struct dso *vdso__dso_findnew(struct list_head *head)
- find/create proper vdso DSO object
vdso__exit(void)
- removes temporary VDSO image if there's any
This change makes backtrace dwarf post unwind possible from [vdso] maps.
Following output is current report of [vdso] sample dwarf backtrace:
# Overhead Command Shared Object Symbol
# ........ ....... ................. .............................
#
99.52% ex [vdso] [.] 0x00007fff3ace89af
|
--- 0x7fff3ace89af
Following output is new report of [vdso] sample dwarf backtrace:
# Overhead Command Shared Object Symbol
# ........ ....... ................. .............................
#
99.52% ex [vdso] [.] 0x00000000000009af
|
--- 0x7fff3ace89af
main
__libc_start_main
_start
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347295819-23177-5-git-send-email-jolsa@redhat.com
[ committer note: s/ALIGN/PERF_ALIGN/g to cope with the android build changes ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Guest kernel symbols are not resolved despite passing the information
needed to resolve them. e.g.,
perf kvm --guest --guestmount=/tmp/guest-mount record -a -- sleep 1
perf kvm --guest --guestmount=/tmp/guest-mount report --stdio
36.55% [guest/11399] [unknown] [g] 0xffffffff81600bc8
33.19% [guest/10474] [unknown] [g] 0x00000000c0116e00
30.26% [guest/11094] [unknown] [g] 0xffffffff8100a288
43.69% [guest/10474] [unknown] [g] 0x00000000c0103d90
37.38% [guest/11399] [unknown] [g] 0xffffffff81600bc8
12.24% [guest/11094] [unknown] [g] 0xffffffff810aa91d
6.69% [guest/11094] [unknown] [u] 0x00007fa784d721c3
which is just pathetic.
After a maddening 2 days sifting through perf minutia I found it --
id_hdr_size is not initialized for guest machines. This shows up on the
report side as random garbage for the cpu and timestamp, e.g.,
29816 7310572949125804849 0x1ac0 [0x50]: PERF_RECORD_MMAP ...
That messes up the sample sorting such that synthesized guest maps are
processed last.
With this patch you get a much more helpful report:
12.11% [guest/11399] [guest.kernel.kallsyms.11399] [g] irqtime_account_process_tick
10.58% [guest/11399] [guest.kernel.kallsyms.11399] [g] run_timer_softirq
6.95% [guest/11094] [guest.kernel.kallsyms.11094] [g] printk_needs_cpu
6.50% [guest/11094] [guest.kernel.kallsyms.11094] [g] do_timer
6.45% [guest/11399] [guest.kernel.kallsyms.11399] [g] idle_balance
4.90% [guest/11094] [guest.kernel.kallsyms.11094] [g] native_read_tsc
...
v2:
- changed rbtree walk to use rb_first per Namhyung's suggestion
Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1342826756-64663-5-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
COMM events are not generated in the context of a guest machine, so the
thread name is never set for the VMM process. For example, the qemu-kvm
name applies to the process in the host machine, not the guest machine.
So, samples for guest machines are currently displayed as:
99.67% :5671 [unknown] [g] 0xffffffff81366b41
where 5671 is the pid of the VMM. With this patch the samples in the guest
machine are shown as:
18.43% [guest/5671] [unknown] [g] 0xffffffff810d68b7
Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1342826756-64663-3-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Using the guestmount option on record:
$ perf kvm --guest --host --guestmount=/tmp/guest-mount record -ag
But not the subsequent report:
$ perf kvm report
causes a SEGFAULT in the usual place:
(gdb) bt
0 0x0000000000470356 in machine__mmap_name (self=0x0, bf=0x7fffffffbdb0 " z\370\367\377\177", size=
4096) at util/map.c:712
1 0x00000000004453e8 in perf_event__process_kernel_mmap (tool=0x7fffffffde10, event=0x7ffff7f87e38,
machine=0x0) at util/event.c:550
2 0x00000000004458c9 in perf_event__process_mmap (tool=0x7fffffffde10, event=0x7ffff7f87e38, sample=
0x7fffffffd2a0, machine=0x0) at util/event.c:656
3 0x00000000004733e0 in perf_session_deliver_event (session=0x91aca0, event=0x7ffff7f87e38, sample=
0x7fffffffd2a0, tool=0x7fffffffde10, file_offset=7736) at util/session.c:979
...
The MMAP events in this case already contain the full path to the
module. No need to require it for the report path to.
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1341241977-71535-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This routine was checking only if the provided address was after
sym->end, not if it was before sym->start.
Fix that by checking for both and return in both cases -ERANGE, so that
tools can communicate this to the user properly, or if they chose so, to
abort.
This problem was reported previously but the fixes involved either doing
what was being done for the > end case, i.e. silently drop the sample,
returning 0, or aborting at this function, which is in a lib (or better,
is slated to be at some point) and shouldn't abort.
The 'report' tool already checks this value and uses pr_debug to warn
the user.
This patch makes the 'top' tool check it too and warn once per map where
such range problem takes place.
Reported-by: David Miller <davem@davemloft.net>
Reported-by: Sorin Dumitru <dumitru.sorin87@gmail.com>
Reported-by: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-lw8gs7p9i9nhldilo82tzpne@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add the option get the path of [kernel.kallsyms].
Specify '--show-kernel-path' option to use this function.
This patch enables other applications to use this output easily.
Without --show-kernel-path option
ffffffff81467612 irq_return ([kernel.kallsyms])
ffffffff81467612 irq_return ([kernel.kallsyms])
7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]
With --show-kernel-path option
ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
ffffffff81467612 irq_return (/lib/modules/3.2.0+/build/vmlinux)
7f24fc02a6b3 _start (/lib64/ld-2.14.so)
[snip]
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120130044320.2384.73322.stgit@linux3
Signed-off-by: Akihiro Nagai <akihiro.nagai.hw@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Following a prelink run mapped files for long running processes can show
as deleted. The current message suggests restarting long running
processes. Add to that a suggestion that prelink might be the cause.
Old message:
/lib64/libc-2.14.so was updated, restart the long running
apps that use it!
New message:
/lib64/libc-2.14.so was updated (is prelink enabled?).
Restart the long running apps that use it!
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1318985085-20776-1-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
