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>
uClibc Linuxthreads.old doesn't support the pthread_attr_setaffinity_np()
functioo:
----------------->8-----------------------
CC bench/futex-hash.o
CC bench/futex-wake.o
bench/futex-hash.c: In function 'bench_futex_hash':
bench/futex-hash.c:161:3: error: implicit declaration of function
'pthread_attr_setaffinity_np' [-Werror=implicit-function-declaration]
ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t),
&cpu);
^
bench/futex-hash.c:161:3: error: nested extern declaration of
'pthread_attr_setaffinity_np' [-Werror=nested-externs]
----------------->8-----------------------
So introduce a test to check that and if not available provide a stub.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1421156604-30603-6-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Block a bunch of threads on a futex and requeue them on another, N at a
time.
This program is particularly useful to measure the latency of nthread
requeues without waking up any tasks -- thus mimicking a regular
futex_wait.
An example run:
$ perf bench futex requeue -r 100 -t 64
Run summary [PID 151011]: Requeuing 64 threads (from 0x7d15c4 to 0x7d15c8), 1 at a time.
[Run 1]: Requeued 64 of 64 threads in 0.0400 ms
[Run 2]: Requeued 64 of 64 threads in 0.0390 ms
[Run 3]: Requeued 64 of 64 threads in 0.0400 ms
...
[Run 100]: Requeued 64 of 64 threads in 0.0390 ms
Requeued 64 of 64 threads in 0.0399 ms (+-0.37%)
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1387081917-9102-4-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Block a bunch of threads on a futex and wake them up, N at a time.
This program is particularly useful to measure the latency of nthread
wakeups in non-error situations: all waiters are queued and all wake
calls wakeup one or more tasks.
An example run:
$ perf bench futex wake -t 512 -r 100
Run summary [PID 27823]: blocking on 512 threads (at futex 0x7e10d4), waking up 1 at a time.
[Run 1]: Wokeup 512 of 512 threads in 6.0080 ms
[Run 2]: Wokeup 512 of 512 threads in 5.2280 ms
[Run 3]: Wokeup 512 of 512 threads in 4.8300 ms
...
[Run 100]: Wokeup 512 of 512 threads in 5.0100 ms
Wokeup 512 of 512 threads in 5.0109 ms (+-2.25%)
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1387081917-9102-3-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Introduce futexes to perf-bench and add a program that stresses and
measures the kernel's implementation of the hash table.
This is a multi-threaded program that simply measures the amount of
failed futex wait calls - we only want to deal with the hashing
overhead, so a negative return of futex_wait_setup() is enough to do the
trick.
An example run:
$ perf bench futex hash -t 32
Run summary [PID 10989]: 32 threads, each operating on 1024 [private] futexes for 10 secs.
[thread 0] futexes: 0x19d9b10 ... 0x19dab0c [ 418713 ops/sec ]
[thread 1] futexes: 0x19daca0 ... 0x19dbc9c [ 469913 ops/sec ]
[thread 2] futexes: 0x19dbe30 ... 0x19dce2c [ 479744 ops/sec ]
...
[thread 31] futexes: 0x19fbb80 ... 0x19fcb7c [ 464179 ops/sec ]
Averaged 454310 operations/sec (+- 0.84%), total secs = 10
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/r/1387081917-9102-2-git-send-email-davidlohr@hp.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Davidlohr Bueso