Commit Graph

10 Commits

Author SHA1 Message Date
Arnaldo Carvalho de Melo 16cab3226f Revert "perf bench futex: Sanitize numeric parameters"
This reverts commit 60758d6668.

Now that libsubcmd makes sure that OPT_UINTEGER options will not
return negative values, we can revert this patch while addressing
the problem it solved:

  # perf bench futex hash -t  -4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  # perf bench futex hash -t-4
  # Running 'futex/hash' benchmark:
   Error: switch `t' expects an unsigned numerical value
   Usage: perf bench futex hash <options>

      -t, --threads <n>     Specify amount of threads
  #

IMO it is more reasonable to flat out refuse to process a negative
number than to silently turn it into an absolute value.

This also helps in silencing clang's complaint about asking for an
absolute value of an unsigned integer:

  bench/futex-hash.c:133:10: error: taking the absolute value of unsigned type 'unsigned int' has no effect [-Werror,-Wabsolute-value]
          nsecs = futexbench_sanitize_numeric(nsecs);
                ^
  bench/futex.h:104:42: note: expanded from macro 'futexbench_sanitize_numeric'
  #define futexbench_sanitize_numeric(__n) abs((__n))
                                           ^
  bench/futex-hash.c:133:10: note: remove the call to 'abs' since unsigned values cannot be negative

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2kl68v22or31vw643m2exz8x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-14 15:19:17 -03:00
Davidlohr Bueso 9de3ffa1b7 perf bench futex: Fix lock-pi help string
Obvious copy/paste typo from the requeue program.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1481830584-30909-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-20 09:37:40 -03:00
Davidlohr Bueso 60758d6668 perf bench futex: Sanitize numeric parameters
This gets rid of oddities such as:

  perf bench futex hash -t -4
  perf: calloc: Cannot allocate memory

Runtime (and many more) are equally busted, i.e. run for bogus amounts of
time. Just use the abs, instead of, for example errorring out.

Committer note:

After the patch:

  $ perf bench futex hash -t -4
  # Running 'futex/hash' benchmark:
  Run summary [PID 10178]: 4 threads, each operating on 1024 [private] futexes for 10 secs.

  [thread  0] futexes: 0x34f9fa0 ... 0x34faf9c [ 4702208 ops/sec ]
  [thread  1] futexes: 0x34fb140 ... 0x34fc13c [ 4707020 ops/sec ]
  [thread  2] futexes: 0x34fc2e0 ... 0x34fd2dc [ 4711526 ops/sec ]
  [thread  3] futexes: 0x34fd480 ... 0x34fe47c [ 4709683 ops/sec ]

  Averaged 4707609 operations/sec (+- 0.04%), total secs = 10
  $

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1477342613-9938-3-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-25 09:50:53 -03:00
Davidlohr Bueso e2e1680fda perf bench futex: Avoid worker cacheline bouncing
Sebastian noted that overhead for worker thread ops (throughput)
accounting was producing 'perf' to appear in the profiles, consuming a
non-trivial (i.e. 13%) amount of CPU.

This is due to cacheline bouncing due to the increment of w->ops.

We can easily fix this by just working on a local copy and updating the
actual worker once done running, and ready to show the program summary.
There is no danger of the worker being concurrent, so we can trust that
no stale value is being seen by another thread.

This also gets rid of the unnecessary cache alignment hack; its not
worth it.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/1477342613-9938-2-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-25 09:50:47 -03:00
Arnaldo Carvalho de Melo 86695f59c9 perf bench futex: Add missing compiler.h header
Since these files use __maybe_unused, and that is defined in
linux/compiler.h, include it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1llbf59ut6xon6ti88jm0n9j@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:20:30 -03:00
Arnaldo Carvalho de Melo 9c304f6c71 perf bench: Disentangle headers
We should try avoiding that perf.h header, it includes way too much
stuff, making it difficult to use things like setting _GNU_SOURCE only
on a small set of headers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-lb6eg9w1kzrwhv0gm3ho0h54@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:19:54 -03:00
Arnaldo Carvalho de Melo 8a15858904 perf bench: Add missing pthread.h include for CPU_*() macros
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-48qbfv7tqs8n8ey74lbyfjtq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:19:52 -03:00
Davidlohr Bueso 73b1794e25 perf bench futex: Simplify wrapper for LOCK_PI
Given that the 'val' parameter is ignored for FUTEX_LOCK_PI, get rid of
the bogus deadlock detection flag in the wrapper code and avoid the
extra argument, making it resemble its unlock counterpart. And if
nothing else, we already only pass 0 anyway.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1461208447-29328-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-25 20:24:26 -03:00
Josh Poimboeuf 4b6ab94eab perf subcmd: Create subcmd library
Move the subcommand-related files from perf to a new library named
libsubcmd.a.

Since we're moving files anyway, go ahead and rename 'exec_cmd.*' to
'exec-cmd.*' to be consistent with the naming of all the other files.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/c0a838d4c878ab17fee50998811612b2281355c1.1450193761.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-12-17 14:27:14 -03:00
Davidlohr Bueso d2f3f5d2e9 perf bench futex: Add lock_pi stresser
Allows a way of measuring low level kernel implementation of FUTEX_LOCK_PI and
FUTEX_UNLOCK_PI.

The program comes in two flavors:

(i) single futex (default), all threads contend on the same uaddr.  For the
sake of the benchmark, we call into kernel space even when the lock is
uncontended.  The kernel will set it to TID, any waters that come in and
contend for the pi futex will be handled respectively by the kernel.

(ii) -M option for multiple futexes, each thread deals with its own futex. This
is a trivial scenario and only measures kernel handling of 0->TID transition.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/r/1436259353.12255.78.camel@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-20 17:49:51 -03:00