The seqcount_t latch reader example at the raw_write_seqcount_latch() kernel-doc comment ends the latch read section with a manual smp memory barrier and sequence counter comparison.
This is technically correct, but it is suboptimal: read_seqcount_retry() already contains the same logic of an smp memory barrier and sequence counter comparison. End the latch read critical section example with read_seqcount_retry(). Signed-off-by: Ahmed S. Darwish <a.darw...@linutronix.de> --- include/linux/seqlock.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index 6c4f68ef1393..d724b5e5408d 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -363,8 +363,8 @@ static inline int raw_read_seqcount_latch(seqcount_t *s) * idx = seq & 0x01; * entry = data_query(latch->data[idx], ...); * - * smp_rmb(); - * } while (seq != latch->seq); + * // read_seqcount_retry() includes needed smp_rmb() + * } while (read_seqcount_retry(&latch->seq, seq)); * * return entry; * } -- 2.20.1
