X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=urcu.c;h=8cb32a117bb065405ca3f45e0224dfe8fbebbf5d;hb=8895e525a86e679e775b8267546799a0e7bc569f;hp=8381f7b6f61bc892cdf25d671d21ef5b05aae9a5;hpb=3a86deba85b5b8bfca24b61610295a764b8f7602;p=userspace-rcu.git diff --git a/urcu.c b/urcu.c index 8381f7b..8cb32a1 100644 --- a/urcu.c +++ b/urcu.c @@ -92,13 +92,20 @@ static void force_mb_single_thread(pthread_t tid) { assert(reader_data); sig_done = 0; - smp_mb(); /* write sig_done before sending the signals */ + /* + * pthread_kill has a smp_mb(). But beware, we assume it performs + * a cache flush on architectures with non-coherent cache. Let's play + * safe and don't assume anything : we use smp_mc() to make sure the + * cache flush is enforced. + * smp_mb(); write sig_done before sending the signals + */ + smp_mc(); /* write sig_done before sending the signals */ pthread_kill(tid, SIGURCU); /* * Wait for sighandler (and thus mb()) to execute on every thread. * BUSY-LOOP. */ - while (LOAD_REMOTE(sig_done) < 1) + while (LOAD_SHARED(sig_done) < 1) cpu_relax(); smp_mb(); /* read sig_done before ending the barrier */ } @@ -115,16 +122,19 @@ static void force_mb_all_threads(void) sig_done = 0; /* * pthread_kill has a smp_mb(). But beware, we assume it performs - * a cache flush on architectures with non-coherent cache. + * a cache flush on architectures with non-coherent cache. Let's play + * safe and don't assume anything : we use smp_mc() to make sure the + * cache flush is enforced. * smp_mb(); write sig_done before sending the signals */ + smp_mc(); /* write sig_done before sending the signals */ for (index = reader_data; index < reader_data + num_readers; index++) pthread_kill(index->tid, SIGURCU); /* * Wait for sighandler (and thus mb()) to execute on every thread. * BUSY-LOOP. */ - while (LOAD_REMOTE(sig_done) < num_readers) + while (LOAD_SHARED(sig_done) < num_readers) cpu_relax(); smp_mb(); /* read sig_done before ending the barrier */ } @@ -149,6 +159,8 @@ void wait_for_quiescent_state(void) if (wait_loops++ == KICK_READER_LOOPS) { force_mb_single_thread(index->tid); wait_loops = 0; + } else { + cpu_relax(); } } }