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2017-03-03perf bench futex: Use __maybe_unusedArnaldo Carvalho de Melo
Instead of attributing a variable to itself to silence the compiler, use the attribute designed for that, avoiding this: In file included from bench/futex-hash.c:24: bench/futex.h:95:7: error: explicitly assigning value of variable of type 'pthread_attr_t *' to itself [-Werror,-Wself-assign] attr = attr; ~~~~ ^ ~~~~ bench/futex.h:96:13: error: explicitly assigning value of variable of type 'size_t' (aka 'unsigned long') to itself [-Werror,-Wself-assign] cpusetsize = cpusetsize; ~~~~~~~~~~ ^ ~~~~~~~~~~ bench/futex.h:97:9: error: explicitly assigning value of variable of type 'cpu_set_t *' (aka 'struct cpu_set_t *') to itself [-Werror,-Wself-assign] cpuset = cpuset; ~~~~~~ ^ ~~~~~~ That is only triggered when HAVE_PTHREAD_ATTR_SETAFFINITY_NP isn't set. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> 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-14ws1d1elj2d5ej8g7cwdqau@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-14Revert "perf bench futex: Sanitize numeric parameters"Arnaldo Carvalho de Melo
This reverts commit 60758d6668b3e2fa8e5fd143d24d0425203d007e. 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>
2016-10-25perf bench futex: Sanitize numeric parametersDavidlohr Bueso
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>
2016-04-25perf bench futex: Simplify wrapper for LOCK_PIDavidlohr Bueso
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>
2015-07-20perf bench futex: Add lock_pi stresserDavidlohr Bueso
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>
2015-01-28perf tools: Provide stub for missing pthread_attr_setaffinity_npVineet Gupta
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>
2014-03-14perf bench: Add futex-requeue microbenchmarkDavidlohr Bueso
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>
2014-03-14perf bench: Add futex-wake microbenchmarkDavidlohr Bueso
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>
2014-03-14perf bench: Add futex-hash microbenchmarkDavidlohr Bueso
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>