Commit d3b35b87 authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by Peter Zijlstra

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: default avatarAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-4-a.darwish@linutronix.de
parent 15cbe67b
...@@ -363,8 +363,8 @@ static inline int raw_read_seqcount_latch(seqcount_t *s) ...@@ -363,8 +363,8 @@ static inline int raw_read_seqcount_latch(seqcount_t *s)
* idx = seq & 0x01; * idx = seq & 0x01;
* entry = data_query(latch->data[idx], ...); * entry = data_query(latch->data[idx], ...);
* *
* smp_rmb(); * // read_seqcount_retry() includes needed smp_rmb()
* } while (seq != latch->seq); * } while (read_seqcount_retry(&latch->seq, seq));
* *
* return entry; * return entry;
* } * }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment