Adding initialized arg into unwind__prepare_access to get feedback about
the initialization state.
It's not possible to get it from error code, because we return 0 even in
case we don't recognize dso, which is valid.
The 'initialized' value is used in following patch to speedup
unwind__prepare_access calls logic in fork path.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1467634583-29147-4-git-send-email-jolsa@kernel.org
[ Remove ; after static inline function signatures, fixes build break ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently, 'perf script' uses host unwind methods to parse perf.data
callchain info without taking the target architecture into account, i.e.
assuming the perf.data file was generated on the same machine where the
analysis is being performed. So we get wrong result without any warnings
when unwinding callchains of x86(32-bit) on x86(64-bit) machine.
This patch adds an extra step that checks the target platform before
assigning unwind methods. In later patches in this series, we can use
this info to assign the right unwind methods for supported platforms.
Committer note:
After fixing it to register the local unwinder for live mode tools
('perf trace', 'perf top'), i.e. tools that don't use a perf.data file,
it works as intended and passes the 'perf test unwind' test:
# perf trace -e nanosleep --call dwarf usleep 1
0.328 ( 0.058 ms): usleep/11115 nanosleep(rqtp: 0x7fff083fa480) = 0
__nanosleep_nocancel+0x7 (/usr/lib64/libc-2.22.so)
usleep+0x34 (/usr/lib64/libc-2.22.so)
main+0x1eb (/usr/bin/usleep)
__libc_start_main+0xf0 (/usr/lib64/libc-2.22.so)
_start+0x29 (/usr/bin/usleep)
# perf test 48
48: Test dwarf unwind : Ok
#
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1464924803-22214-11-git-send-email-hekuang@huawei.com
[ Fixed exit path for 'live' mode tools, where we need to default to local unwinding ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
As reported by Milian, currently for DWARF unwind (both libdw and
libunwind) we display callchain in callee order only.
Adding the support to follow callchain order setup to libunwind DWARF
unwinder, so we could get following output for report:
$ perf record --call-graph dwarf ls
...
$ perf report --no-children --stdio
39.26% ls libc-2.21.so [.] __strcoll_l
|
---__strcoll_l
mpsort_with_tmp
mpsort_with_tmp
sort_files
main
__libc_start_main
_start
0
$ perf report -g caller --no-children --stdio
...
39.26% ls libc-2.21.so [.] __strcoll_l
|
---0
_start
__libc_start_main
main
sort_files
mpsort_with_tmp
mpsort_with_tmp
__strcoll_l
Based-on-patch-by: Milian Wolff <milian.wolff@kdab.com>
Reported-and-Tested-by: Milian Wolff <milian.wolff@kdab.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Wang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20151118075247.GA5416@krava.brq.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
unw_word_t is uint64_t even on 32-bit MIPS. Cast it to uintptr_t before
the cast to void *p to get rid of the following errors:
util/unwind-libunwind.c: In function 'access_mem':
util/unwind-libunwind.c:464:4: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
util/unwind-libunwind.c:475:2: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
cc1: all warnings being treated as errors
make[3]: *** [util/unwind-libunwind.o] Error 1
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rabin Vincent <rabinv@axis.com>
Link: http://lkml.kernel.org/r/1443379079-29133-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Commit f1f13af99a ("perf callchain: Cache eh/debug frame offset for
dwarf unwind") introduces a cache for .debug_frame and .eh_frame_hdr.
Unfortunately, it makes them share a same cache (dso->frame_offset).
Which causes unwind failure on ARM:
$ perf test unwind
Test dwarf unwind: FAILED!
The reason is that, if a dso has '.debug_frame' but doesn't have
'.eh_frame_hdr' (like ARM), dso->frame_offset will be filled by offset
of '.debug_frame' during the first time calling of find_proc_info() ->
read_unwind_spec_debug_frame(), and be regarded to '.eh_frame_hdr' when
the second time calling of find_proc_info() ->
read_unwind_spec_eh_frame(), since '.eh_frame_hdr' is checked prior to
'.debug_frame'.
This patch solves the problem by creating two cache fields for
'.eh_frame_hdr' and '.debug_frame'.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/55028BA0.1030701@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Perf tool fails to unwind user stack if the event raises in a shared
object. This patch improves tests/dwarf-unwind.c to demonstrate the
problem by utilizing commonly used glibc function "bsearch". If perf is
not statically linked, the testcase will try to unwind a mixed call
trace.
By debugging libunwind I found that there is a bug in unwind-libunwind:
it always passes 0 as segbase to libunwind, cause libunwind unable to
locate debug_frame entry fir first level ip address (I add some more
debugging output into libunwind to make things clear):
>_Uarm_dwarf_find_debug_frame: start_ip = 10be98, end_ip = 10c2a4
>_Uarm_dwarf_find_debug_frame: found debug_frame table `/lib/libc-2.18.so': segbase=0x0, len=7, gp=0x0, table_data=0x449388
>_Uarm_dwarf_search_unwind_table: call lookup:ip = b6cd3bcc, segbase = 0, rel_ip = b6cd3bcc
>lookup: e->start_ip_offset = bcf18 (rel_ip = b6cd3bcc)
>lookup: e->start_ip_offset = 6d314 (rel_ip = b6cd3bcc)
>lookup: e->start_ip_offset = 33d0c (rel_ip = b6cd3bcc)
...
>lookup: e->start_ip_offset = 15d0c (rel_ip = b6cd3bcc)
>lookup: e->start_ip_offset = 15c40 (rel_ip = b6cd3bcc)
>_Uarm_dwarf_search_unwind_table: IP b6cd3bcc inside range b6c12000-b6d4c000, but no explicit unwind info found
>put_rs_cache: unmasking signals/interrupts and releasing lock
>_Uarm_dwarf_step: returning -10
>_Uarm_step: dwarf_step()=-10
This patch passes map->start as segbase to dwarf_find_debug_frame(), so
di will be initialized correctly.
In addition, dso and executable are different when setting segbase. This
patch first check whether the elf is executable, and pass segbase only
for shared object.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1421203007-75799-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The unw_addr_space_t in libunwind represents an address space to be used
for stack unwinding. It doesn't need to be create/destory everytime to
unwind callchain (as in get_entries) and can have a same lifetime as
thread (unless exec called).
So move the address space construction/destruction logic to the thread
lifetime handling functions. This is a preparation to enable caching in
the unwind library.
Note that it saves unw_addr_space_t object using thread__set_priv(). It
seems currently only used by perf trace and perf kvm stat commands which
don't use callchain.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jean Pihet <jean.pihet@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1412556363-26229-3-git-send-email-namhyung@kernel.org
[ Fixup unwind-libunwind.c missing CALLCHAIN_DWARF definition, added
missing __maybe_unused on unused parameters in stubs at util/unwind.h ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Caching dso data file descriptors to avoid expensive re-opens
especially during DWARF unwind.
We keep dsos data file descriptors open until their count reaches
the half of the current fd open limit (RLIMIT_NOFILE). In this case
we close file descriptor of the first opened dso object.
We've got overall speedup (~27% for my workload) of report:
'perf report --stdio -i perf-test.data' (3 runs)
(perf-test.data size was around 12GB)
current code:
545,640,944,228 cycles ( +- 0.53% )
785,255,798,320 instructions ( +- 0.03% )
366.340910010 seconds time elapsed ( +- 3.65% )
after change:
435,895,036,114 cycles ( +- 0.26% )
636,790,271,176 instructions ( +- 0.04% )
266.481463387 seconds time elapsed ( +- 0.13% )
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1401892622-30848-7-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
