Messages in this thread Patch in this message | | | From | Tom Zanussi <> | Subject | [PATCH 08/15] seqlock: provide the same ordering semantics as mainline | Date | Thu, 2 Aug 2018 17:25:23 -0500 |
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From: Julia Cartwright <julia@ni.com>
The mainline implementation of read_seqbegin() orders prior loads w.r.t. the read-side critical section. Fixup the RT writer-boosting implementation to provide the same guarantee.
Also, while we're here, update the usage of ACCESS_ONCE() to use READ_ONCE().
Fixes: e69f15cf77c23 ("seqlock: Prevent rt starvation") Cc: stable-rt@vger.kernel.org Signed-off-by: Julia Cartwright <julia@ni.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> (cherry picked from commit afa4c06b89a3c0fb7784ff900ccd707bef519cb7) Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> --- include/linux/seqlock.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 4acd0e2fb5cb..efa234031230 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -338,6 +338,7 @@ repeat: spin_unlock_wait(&sl->lock); goto repeat; } + smp_rmb(); return ret; } #endif -- 2.14.1
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