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Subject[PATCH v4 03/24] seqlock: seqcount_t latch: End read sections with read_seqcount_retry()
Date
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>
---
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
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