This has a different model than the 'thread' and 'map' struct lifetimes:
there is not a definitive "don't use this DSO anymore" event, i.e. we may
get many 'struct map' holding references to the '/usr/lib64/libc-2.20.so'
DSO but then at some point some DSO may have no references but we still
don't want to straight away release its resources, because "soon" we may
get a new 'struct map' that needs it and we want to reuse its symtab or
other resources.
So we need some way to garbage collect it when crossing some memory
usage threshold, which is left for anoter patch, for now it is
sufficient to release it when calling dsos__exit(), i.e. when deleting
the whole list as part of deleting the 'struct machine' containing it,
which will leave only referenced objects being used.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-majzgz07cm90t2tejrjy4clf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before patch ba92732e98 ('perf kmaps: Check kmaps to make code more
robust'), 'perf report' and 'perf annotate' will segfault if trace data
contains kernel module information like this:
# perf report -D -i ./perf.data
...
0 0 0x188 [0x50]: PERF_RECORD_MMAP -1/0: [0xffffffbff1018000(0xf068000) @ 0]: x [test_module]
...
# perf report -i ./perf.data --objdump=/path/to/objdump --kallsyms=/path/to/kallsyms
perf: Segmentation fault
-------- backtrace --------
/path/to/perf[0x503478]
/lib64/libc.so.6(+0x3545f)[0x7fb201f3745f]
/path/to/perf[0x499b56]
/path/to/perf(dso__load_kallsyms+0x13c)[0x49b56c]
/path/to/perf(dso__load+0x72e)[0x49c21e]
/path/to/perf(map__load+0x6e)[0x4ae9ee]
/path/to/perf(thread__find_addr_map+0x24c)[0x47deec]
/path/to/perf(perf_event__preprocess_sample+0x88)[0x47e238]
/path/to/perf[0x43ad02]
/path/to/perf[0x4b55bc]
/path/to/perf(ordered_events__flush+0xca)[0x4b57ea]
/path/to/perf[0x4b1a01]
/path/to/perf(perf_session__process_events+0x3be)[0x4b428e]
/path/to/perf(cmd_report+0xf11)[0x43bfc1]
/path/to/perf[0x474702]
/path/to/perf(main+0x5f5)[0x42de95]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x7fb201f23bd4]
/path/to/perf[0x42dfc4]
This is because __kmod_path__parse treats '[' leading names as kernel
name instead of names of kernel module.
If perf.data contains build information and the buildid of such modules
can be found, the dso->kernel of it will be set to DSO_TYPE_KERNEL by
__event_process_build_id(), not kernel module.
It will then be passed to dso__load() -> dso__load_kernel_sym() ->
dso__load_kcore() if --kallsyms is provided.
The refered patch adds NULL pointer checker to avoid segfault. However,
such kernel modules are still processed incorrectly.
This patch fixes __kmod_path__parse, makes it treat names like
'[test_module]' as kernel modules.
kmod-path.c is also update to reflect the above changes.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1433321541-170245-1-git-send-email-wangnan0@huawei.com
[ Fixed the merged with 0443f36b0d ("perf machine: Fix the search
for the kernel DSO on the unified list" ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
mmap-basic fails on arm64.
4: read samples using the mmap interface: read samples using the mmap interface: FAILED!
This is because arm64 doesn't come with getpgrp() syscall. The syscall
is a BSD compatibility wrapper, Archs that don't define
__ARCH_WANT_SYS_GETPGRP do not have this. Remove it, since getpgid is
already used in the testcase.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1429192375-13706-4-git-send-email-riku.voipio@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Multiple perf tests fail on arm64 due to missing open syscall:
2: detect open syscall event : FAILED!
open(2) is a legacy syscall, replaced with openat(2) since 2.6.16. Thus
new architectures in kernel, such as arm64, don't implement these legacy
syscalls.
The patch replaces all sys_enter_open events with sys_enter_openat,
renames the related tests and test output to avoid confusion.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1429192375-13706-2-git-send-email-riku.voipio@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When introducing reference counting for struct thread instances I forgot
to remove the synthetic threads from the machine's rbtree so that it
then the threads would have just one reference and thus the
thread__put() replacing the thread__delete() really turns into a
thread__delete() (thread->refcnt == 1 at thread__put() time) and thus
drop the thread->mg refcount, as expected by the this test.
Fix it by calling machine__remove_thread() (the counterpart of
machine__findnew_thread()) on all the synthetic threads after the
checks that involves the rbtree were done.
Before:
# perf test -v mg
30: Test thread mg sharing :
--- start ---
test child forked, pid 26995
FAILED tests/thread-mg-share.c:68 wrong refcnt (4 != 3)
test child finished with -1
---- end ----
Test thread mg sharing: FAILED!
#
After:
# perf test mg
30: Test thread mg sharing: Ok
#
Fixes: b91fc39f4a ("perf machine: Protect the machine->threads with a rwlock")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uoqq0fjei90ohhhcboz6ay33@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
