summaryrefslogtreecommitdiff
path: root/include/linux/seqlock.h
diff options
context:
space:
mode:
authorDavidlohr Bueso <dave@stgolabs.net>2015-02-23 06:31:41 +0300
committerIngo Molnar <mingo@kernel.org>2015-02-24 10:44:16 +0300
commit4d3199e4ca8e6670b54dc5ee070ffd54385988e9 (patch)
tree5529bcb16c3217c02416e0d17d7c28f277c63581 /include/linux/seqlock.h
parent2ae79026818e7d49fead82b79b1a543e3b9c8a23 (diff)
downloadlinux-4d3199e4ca8e6670b54dc5ee070ffd54385988e9.tar.xz
locking: Remove ACCESS_ONCE() usage
With the new standardized functions, we can replace all ACCESS_ONCE() calls across relevant locking - this includes lockref and seqlock while at it. ACCESS_ONCE() does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 Update the new calls regardless of if it is a scalar type, this is cleaner than having three alternatives. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1424662301.6539.18.camel@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/seqlock.h')
-rw-r--r--include/linux/seqlock.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index f5df8f687b4d..5f68d0a391ce 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -108,7 +108,7 @@ static inline unsigned __read_seqcount_begin(const seqcount_t *s)
unsigned ret;
repeat:
- ret = ACCESS_ONCE(s->sequence);
+ ret = READ_ONCE(s->sequence);
if (unlikely(ret & 1)) {
cpu_relax();
goto repeat;
@@ -127,7 +127,7 @@ repeat:
*/
static inline unsigned raw_read_seqcount(const seqcount_t *s)
{
- unsigned ret = ACCESS_ONCE(s->sequence);
+ unsigned ret = READ_ONCE(s->sequence);
smp_rmb();
return ret;
}
@@ -179,7 +179,7 @@ static inline unsigned read_seqcount_begin(const seqcount_t *s)
*/
static inline unsigned raw_seqcount_begin(const seqcount_t *s)
{
- unsigned ret = ACCESS_ONCE(s->sequence);
+ unsigned ret = READ_ONCE(s->sequence);
smp_rmb();
return ret & ~1;
}