Messages in this thread | | | Date | Sun, 6 Sep 2009 20:42:14 +0200 | From | Jens Axboe <> | Subject | Re: [RFC PATCH] v2 mm: balance_dirty_pages. reduce calls to global_page_state to reduce cache references |
| |
On Fri, Sep 04 2009, Richard Kennedy wrote: > Reducing the number of times balance_dirty_pages calls global_page_state > reduces the cache references and so improves write performance on a > variety of workloads. > > 'perf stats' of simple fio write tests shows the reduction in cache > access. > Where the test is fio 'write,mmap,600Mb,pre_read' on AMD AthlonX2 with > 3Gb memory (dirty_threshold approx 600 Mb) > running each test 10 times, dropping the fasted & slowest values then > taking > the average & standard deviation > > average (s.d.) in millions (10^6) > 2.6.31-rc8 648.6 (14.6) > +patch 620.1 (16.5)
This patch looks good to me, I have workloads too here where up to 10% of the time is spent in balance_dirty_pages() because of this. I'll give this patch a go on the box and test in question tomorrow, but it looks promising.
-- Jens Axboe
| |