diff options
| author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-07-20 17:55:09 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-29 16:14:23 +0200 |
| commit | d3b35b87f436c1b226a8061bee9c8875ba6658bd (patch) | |
| tree | cad4767b0a4fdc9e78dbb30128c0654e81fcf2af | |
| parent | 15cbe67bbd3adeb4854c42713dbeaf2ff876beee (diff) | |
seqlock: seqcount_t latch: End read sections with read_seqcount_retry()
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.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-4-a.darwish@linutronix.de
| -rw-r--r-- | include/linux/seqlock.h | 4 |
1 files 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; * } |