From: Jens Axboe Takashi did some nice latency testing of the current kernel (with -mm writeback changes), and the biggest offender in general core is mpage_writepages(). --- 25-akpm/fs/mpage.c | 1 + 1 files changed, 1 insertion(+) diff -puN fs/mpage.c~mpage_writepages-latency-fix fs/mpage.c --- 25/fs/mpage.c~mpage_writepages-latency-fix 2004-03-24 02:53:04.336992776 -0800 +++ 25-akpm/fs/mpage.c 2004-03-24 02:53:04.339992320 -0800 @@ -679,6 +679,7 @@ retry: } } pagevec_release(&pvec); + cond_resched(); } if (!scanned && !done) { /* _