linux-toradex.git/tools/perf/util/dso.c, branch v4.8

tools: Introduce str_error_r()

2016-07-12T18:19:47+00:00

The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.

But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.

So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow to reset open files counter

2016-06-30T21:27:44+00:00

I hit a bug when running test suite without forking
each test (-F option):

  $ perf test -F dso
   8: Test dso data read                                       : Ok
   9: Test dso data cache                                      : FAILED!
  10: Test dso data reopen                                     : FAILED!

The reason the session file limit is set just once for
perf process so we need to reset it for each test,
otherwise wrong limit is taken into account.

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Tested-by: Nilay Vaish 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1467113345-12669-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Set buildid dir under symfs when --symfs is provided

2016-05-20T14:43:58+00:00

This patch moves the reference of buildid dir to 'symfs/.debug' and
skips the local buildid dir when '--symfs' is given, so that every
single file opened by perf is relative to symfs directory now.

Signed-off-by: He Kuang 
Acked-by: David Ahern 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ekaterina Tumanova 
Cc: Josh Poimboeuf 
Cc: Kan Liang 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Sukadev Bhattiprolu 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1463658462-85131-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Store vdso buildid unconditionally

2016-05-17T02:11:45+00:00

When unwinding callchains on a different machine, vdso info should be
available so the unwind process won't be interrupted if address falls
into vdso region. But in most cases, the addresses of sample events are
not in vdso range, the buildid of a zero hit vdso won't be stored into
perf.data.

This patch stores vdso buildid regardless of whether the vdso is hit or
not.

Signed-off-by: He Kuang 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Ekaterina Tumanova 
Cc: Jiri Olsa 
Cc: Josh Poimboeuf 
Cc: Kan Liang 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Pekka Enberg 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Sukadev Bhattiprolu 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/1463042596-61703-3-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use SBUILD_ID_SIZE where applicable

2016-05-11T16:06:06+00:00

Use the existing SBUILD_ID_SIZE macro instead of the equivalent
BUILD_ID_SIZE * 2 + 1 expression for allocating a buffer for build-id
strings.

Signed-off-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Brendan Gregg 
Cc: Hemant Kumar 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20160511135159.23943.57120.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Do not read symbols/data from device files

2016-01-26T14:52:43+00:00

With mem sampling we could get data source within mapped device file.
Processing such sample would block during report phase on trying to read
the device file.

Chacking for device files and skip the processing if it's detected.

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1453290995-18485-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix dsosaddnew to put dso after adding it to the list

2015-11-19T16:19:20+00:00

__dsos__addnew should drop the constructor reference to dso after adding
it to the list, because __dsos__add() will get a reference that will be
kept while it is in the list.

This fixes DSO leaks when entries are removed to the list and the refcount
never gets to zero.

Refcnt debugger shows:
  ==== [0] ====
  Unreclaimed dso: 0x2fccab0
  Refcount +1 => 1 at
    ./perf(dso__new+0x1ff) [0x4a62df]
    ./perf(__dsos__addnew+0x29) [0x4a6e19]
    ./perf(dsos__findnew+0xd1) [0x4a7281]
    ./perf(machine__findnew_kernel+0x27) [0x4a5e17]
    ./perf() [0x4b8df2]
    ./perf(machine__create_kernel_maps+0x28) [0x4bb528]
    ./perf(machine__new_host+0xfa) [0x4bb84a]
    ./perf(init_probe_symbol_maps+0x93) [0x506713]
    ./perf() [0x455ffa]
    ./perf(cmd_probe+0x6c) [0x4566bc]
    ./perf() [0x47abc5]
    ./perf(main+0x610) [0x421f90]
    /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f46df132af5]
    ./perf() [0x4220a9]
  Refcount +1 => 2 at
    ./perf(__dsos__addnew+0xfb) [0x4a6eeb]
    ./perf(dsos__findnew+0xd1) [0x4a7281]
    ./perf(machine__findnew_kernel+0x27) [0x4a5e17]
    ./perf() [0x4b8df2]
    ./perf(machine__create_kernel_maps+0x28) [0x4bb528]
    ./perf(machine__new_host+0xfa) [0x4bb84a]
    ./perf(init_probe_symbol_maps+0x93) [0x506713]
    ./perf() [0x455ffa]
    ./perf(cmd_probe+0x6c) [0x4566bc]
    ./perf() [0x47abc5]
    ./perf(main+0x610) [0x421f90]
    /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f46df132af5]
    ./perf() [0x4220a9]
  Refcount +1 => 3 at
    ./perf(dsos__findnew+0x7e) [0x4a722e]
    ./perf(machine__findnew_kernel+0x27) [0x4a5e17]
    ./perf() [0x4b8df2]
    ./perf(machine__create_kernel_maps+0x28) [0x4bb528]
    ./perf(machine__new_host+0xfa) [0x4bb84a]
    ./perf(init_probe_symbol_maps+0x93) [0x506713]
    ./perf() [0x455ffa]
    ./perf(cmd_probe+0x6c) [0x4566bc]
    ./perf() [0x47abc5]
    ./perf(main+0x610) [0x421f90]
    /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f46df132af5]
    ./perf() [0x4220a9]
  [snip]

Signed-off-by: Masami Hiramatsu 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20151118064031.30709.81460.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Fix dso lookup by long name and missing buildids

2015-11-13T14:14:36+00:00

Commit 4598a0a6d22f ("perf symbols: Improve DSO long names lookup speed
with rbtree") Added a tree to lookup dsos by long name.  That tree gets
corrupted whenever a dso long name is changed because the tree is not
updated.

One effect of that is buildid-list does not work with the 'with-hits'
option because dso lookup fails and results in two structs for the same
dso.  The first has the buildid but no hits, the second has hits but no
buildid. e.g.

Before:

  $ tools/perf/perf record ls
  arch     certs    CREDITS  Documentation  firmware  include
  ipc      Kconfig  lib      Makefile       net       REPORTING-BUGS
  scripts  sound    usr      block          COPYING   crypto
  drivers  fs       init     Kbuild         kernel    MAINTAINERS
  mm       README   samples  security       tools     virt
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data (11 samples) ]
  $ tools/perf/perf buildid-list
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so
  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  0000000000000000000000000000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so

After:

  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so

The fix is to record the root of the tree on the dso so that
dso__set_long_name() can update the tree when the long name changes.

Signed-off-by: Adrian Hunter 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Don Zickus 
Cc: Douglas Hatch 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Scott J Norton 
Cc: Waiman Long 
Fixes: 4598a0a6d22f ("perf symbols: Improve DSO long names lookup speed with rbtree")
Link: http://lkml.kernel.org/r/1447408112-1920-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Reference count struct dso

2015-06-08T13:31:40+00:00

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 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/n/tip-majzgz07cm90t2tejrjy4clf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Protect accesses the dso rbtrees/lists with a rw lock