On 21/06/11 15:34, Mel Gorman wrote: > On Tue, Jun 21, 2011 at 12:59:00PM +0100, P?draig Brady wrote: >> On 21/06/11 12:34, Mel Gorman wrote: >>> On Tue, Jun 21, 2011 at 11:47:35AM +0100, P?draig Brady wrote: >>>> On 21/06/11 11:39, Mel Gorman wrote: >>>>> On Tue, Jun 21, 2011 at 10:53:02AM +0100, P?draig Brady wrote: >>>>>> I tried the 2 patches here to no avail: >>>>>> http://marc.info/?l=linux-mm&m=130503811704830&w=2 >>>>>> >>>>>> I originally logged this at: >>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=712019 >>>>>> >>>>>> I can compile up and quickly test any suggestions. >>>>>> >>>>> >>>>> I recently looked through what kswapd does and there are a number >>>>> of problem areas. Unfortunately, I haven't gotten around to doing >>>>> anything about it yet or running the test cases to see if they are >>>>> really problems. In your case, the following is a strong possibility >>>>> though. This should be applied on top of the two patches merged from >>>>> that thread. >>>>> >>>>> This is not tested in any way, based on 3.0-rc3 >>>> >>>> This does not fix the issue here. >>>> >>> >>> I made a silly mistake here. When you mentioned two patches applied, >>> I assumed you meant two patches that were finally merged from that >>> discussion thread instead of looking at your linked mail. Now that I >>> have checked, I think you applied the SLUB patches while the patches >>> I was thinking of are; >>> >>> [afc7e326: mm: vmscan: correct use of pgdat_balanced in sleeping_prematurely] >>> [f06590bd: mm: vmscan: correctly check if reclaimer should schedule during shrink_slab] >>> >>> The first one in particular has been reported by another user to fix >>> hangs related to copying large files. I'm assuming you are testing >>> against the Fedora kernel. As these patches were merged for 3.0-rc1, can >>> you check if applying just these two patches to your kernel helps? >> >> These patches are already present in my 2.6.38.8-32.fc15.x86_64 kernel :( >> > > While doing a review of patches for unrelated reasons between 2.6.38 > and 3.0-rc3, I noted a few patches related to high CPU usage that may > not have made it to the Fedora kernel. > > * d527caf2 mm: compaction: prevent kswapd compacting memory to reduce CPU usage > * 929bea7c vmscan: all_unreclaimable() use zone->all_unreclaimable as a name > * afc7e326 mm: vmscan: correct use of pgdat_balanced in sleeping_prematurely > * f06590bd mm: vmscan: correctly check if reclaimer should schedule during shrink_slab Those were already applied, yes. > 8afdcece mm: vmscan: kswapd should not free an excessive number of pages when balancing small zones > 602605a4 mm: compaction: minimise the time IRQs are disabled while isolating free pages > b2eef8c0 mm: compaction: minimise the time IRQs are disabled while isolating pages for migration The above had no effect. cheers, Pádraig. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>