Messages in this thread Patch in this message | | | Date | Mon, 27 Oct 2014 16:31:16 -0400 (EDT) | Subject | Re: futex testsuite suggestion... | From | David Miller <> |
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From: Darren Hart <dvhart@linux.intel.com> Date: Mon, 27 Oct 2014 13:29:14 -0700
> On 10/27/14 12:56, David Miller wrote: >> I'd like to suggest that you add a test that triggers transparent >> hugepages, because if an architecture doesn't implement >> __get_user_pages_fast() such futexes cause a machine to hang. >> >> I hacked up something simple that took the existing performance >> test and made it operate in a register allocated using memalign(). >> >> I would suggest doing a memalign(HUGEPAGE_SIZE, HUGEPAGE_SIZE) then >> iterating running a futex test within each normal page within that >> hugepage. > > Do you want this option for the performance tests, or would a less > intensive functional test be sufficient?
I think a functional test is sufficient.
> I'm perfectly happy to add such a test. I'm currently buried under a > number of other things that have resulted in futextests suffering > somewhat. So a couple of things to help make this happen: > > 1) Could you send me your hacked up test, in whatever condition?
See at the end of this email.
> 2) I'm more than happy to accept patches, but I do understand why you > might prefer to have someone else write it :-)
I could find time to work on this. :)
diff --git a/performance/harness.h b/performance/harness.h index a395492..5cfd09b 100644 --- a/performance/harness.h +++ b/performance/harness.h @@ -38,6 +38,7 @@ #include <limits.h> #include <pthread.h> #include <stdio.h> +#include <malloc.h> #include <sys/times.h> #include "logging.h" @@ -102,35 +103,39 @@ static void * locktest_thread(void * dummy) static int locktest(void locktest_function(futex_t * ptr, int loops), int iterations, int threads) { - struct locktest_shared shared; + struct locktest_shared *shared; pthread_t thread[threads]; + void *buf; int i; clock_t before, after; struct tms tms_before, tms_after; int wall, user, system; double tick; - barrier_init(&shared.barrier_before, threads); - barrier_init(&shared.barrier_after, threads); - shared.locktest_function = locktest_function; - shared.loops = iterations / threads; - shared.futex = 0; + buf = memalign(8 * 1024 * 1024, 8 * 1024 * 1024); + shared = (buf + (8 * 1024 * 1024) - sizeof(*shared)); + + barrier_init(&shared->barrier_before, threads); + barrier_init(&shared->barrier_after, threads); + shared->locktest_function = locktest_function; + shared->loops = iterations / threads; + shared->futex = 0; for (i = 0; i < threads; i++) if (pthread_create(thread + i, NULL, locktest_thread, - &shared)) { + shared)) { error("pthread_create\n", errno); /* Could not create thread; abort */ - barrier_unblock(&shared.barrier_before, -1); + barrier_unblock(&shared->barrier_before, -1); while (--i >= 0) pthread_join(thread[i], NULL); print_result(RET_ERROR); return RET_ERROR; } - barrier_wait(&shared.barrier_before); + barrier_wait(&shared->barrier_before); before = times(&tms_before); - barrier_unblock(&shared.barrier_before, 1); - barrier_wait(&shared.barrier_after); + barrier_unblock(&shared->barrier_before, 1); + barrier_wait(&shared->barrier_after); after = times(&tms_after); wall = after - before; user = tms_after.tms_utime - tms_before.tms_utime; @@ -139,12 +144,12 @@ static int locktest(void locktest_function(futex_t * ptr, int loops), info("%.2fs user, %.2fs system, %.2fs wall, %.2f cores\n", user * tick, system * tick, wall * tick, wall ? (user + system) * 1. / wall : 1.); - barrier_unblock(&shared.barrier_after, 1); + barrier_unblock(&shared->barrier_after, 1); for (i = 0; i < threads; i++) pthread_join(thread[i], NULL); printf("Result: %.0f Kiter/s\n", - (threads * shared.loops) / (wall * tick * 1000)); + (threads * shared->loops) / (wall * tick * 1000)); return RET_PASS; }
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