diff options
| author | Alexander Bluhm <bluhm@cvs.openbsd.org> | 2017-01-11 17:46:29 +0000 |
|---|---|---|
| committer | Alexander Bluhm <bluhm@cvs.openbsd.org> | 2017-01-11 17:46:29 +0000 |
| commit | 4009b5e2d48bb5ac4159e510e77b93c9bb9d0d7e (patch) | |
| tree | f820979f8fd6e80145a52bfb7e91498bea633982 /sys/kern/subr_percpu.c | |
| parent | 535ca4dad3ad8541b5ac1993ef50b0192763d316 (diff) | |
Move the membar in counters_read(). It has to be between reading
the generation number and the counters. In counters_zero() put a
membar after resetting the counters, but before writing the generation
number.
OK mpi@ patrick@
Diffstat (limited to 'sys/kern/subr_percpu.c')
| -rw-r--r-- | sys/kern/subr_percpu.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/sys/kern/subr_percpu.c b/sys/kern/subr_percpu.c index 8ff00635165..d009f646e9c 100644 --- a/sys/kern/subr_percpu.c +++ b/sys/kern/subr_percpu.c @@ -1,4 +1,4 @@ -/* $OpenBSD: subr_percpu.c,v 1.5 2016/10/27 09:40:20 dlg Exp $ */ +/* $OpenBSD: subr_percpu.c,v 1.6 2017/01/11 17:46:28 bluhm Exp $ */ /* * Copyright (c) 2016 David Gwynne <dlg@openbsd.org> @@ -181,10 +181,10 @@ counters_read(struct cpumem *cm, uint64_t *output, unsigned int n) /* the generation number is odd during an update */ while (enter & 1) { yield(); - membar_consumer(); enter = *gen; } + membar_consumer(); for (i = 0; i < n; i++) temp[i] = counters[i]; @@ -213,12 +213,13 @@ counters_zero(struct cpumem *cm, unsigned int n) uint64_t *counters; unsigned int i; - n++; /* zero the generation numbers too */ - counters = cpumem_first(&cmi, cm); do { for (i = 0; i < n; i++) counters[i] = 0; + /* zero the generation numbers too */ + membar_producer(); + counters[i] = 0; counters = cpumem_next(&cmi, cm); } while (counters != NULL); @@ -334,4 +335,3 @@ counters_zero(struct cpumem *cm, unsigned int n) } #endif /* MULTIPROCESSOR */ - |