Did this patch get merged somewhere? On Thu, May 20, 2010 at 07:20:42AM -0400, Larry Woodman wrote: > We've seen multiple performance regressions linked to the lower(20%) > dirty_ratio. When performing enough IO to overwhelm the background > flush daemons the percent of dirty pagecache memory quickly climbs > to the new/lower dirty_ratio value of 20%. At that point all > writing processes are forced to stop and write dirty pagecache pages > back to disk. This causes performance regressions in several > benchmarks as well as causing > a noticeable overall sluggishness. We all know that the dirty_ratio is > an integrity vs performance trade-off but the file system journaling > will cover any devastating effects in the event of a system crash. > > Increasing the dirty_ratio to 40% will regain the performance loss seen > in several benchmarks. Whats everyone think about this??? > > > > > > ------------------------------------------------------------------------ > > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index ef27e73..645a462 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -78,7 +78,7 @@ int vm_highmem_is_dirtyable; > /* > * The generator of dirty data starts writeback at this percentage > */ > -int vm_dirty_ratio = 20; > +int vm_dirty_ratio = 40; > > /* > * vm_dirty_bytes starts at 0 (disabled) so that it is a function of > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxxx For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> ---end quoted text--- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>