lkml.org 
[lkml]   [2019]   [Oct]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm/swap: piggyback lru_add_drain_all() calls
On Fri, Oct 04, 2019 at 01:11:06PM +0300, Konstantin Khlebnikov wrote:
> This is very slow operation. There is no reason to do it again if somebody
> else already drained all per-cpu vectors after we waited for lock.
> + seq = raw_read_seqcount_latch(&seqcount);
> +
> mutex_lock(&lock);
> +
> + /* Piggyback on drain done by somebody else. */
> + if (__read_seqcount_retry(&seqcount, seq))
> + goto done;
> +
> + raw_write_seqcount_latch(&seqcount);
> +

Do we really need the seqcount to do this? Wouldn't a mutex_trylock()
have the same effect?

\
 
 \ /
  Last update: 2019-10-04 14:10    [W:0.061 / U:1.636 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site