On Tue, Oct 06, 2009 at 02:14:26AM -0700, David Rientjes wrote: > On Tue, 6 Oct 2009, Mel Gorman wrote: > > > > > And the winner is: > > > > 2ff05b2b4eac2e63d345fc731ea151a060247f53 is first bad commit > > > > commit 2ff05b2b4eac2e63d345fc731ea151a060247f53 > > > > Author: David Rientjes <rientjes@xxxxxxxxxx> > > > > Date: Tue Jun 16 15:32:56 2009 -0700 > > > > > > > > oom: move oom_adj value from task_struct to mm_struct > > > > > > > > I'm confident that the bisection is good. The test case was very reliable > > > > while zooming in on the merge from akpm. > > > > > > > > > > I doubt it for two reasons: (i) this commit was reverted in 0753ba0 since > > > 2.6.31-rc7 and is no longer in the kernel, and (ii) these are GFP_ATOMIC > > > allocations which would be unaffected by oom killer scores. > > > > > > > However, the problem was reported to start showing up in 2.6.31-rc1 so > > while it might not be *the* patch, it might be making the type of change > > that caused more fragmentation. This patch adjusted the size of > > mm_struct and maybe it was enough to change the "order" required for the > > slab. Maybe there are other slabs that have changed size as well in that > > timeframe. > > > > Frans, what is the size of mm_struct before and after this patch was > > applied? Find it with either > > > > grep mm_struct /proc/slabinfo > > > > and if the information is not available there, try > > > > cat /sys/kernel/slab/mm_struct/slab_size and > > /sys/kernel/slab/mm_struct/order > > > > If that's the case and the problem still persists in 2.6.31-rc7 as > reported, then you'd need to compare the current slab order for both > mm_struct and signal_struct to the previously known working kernel > since the latter is where oom_adj was moved. (You'd still have to check > the former to see if there were any mm_struct additions between rc1 and > rc7 between the commit and revert, though.) > Best to just grab all of slabinfo for a poke around. I know task_struct has increases in size since 2.6.29 but not enough on the machines I've changed to make a difference to the order of pages requested. It might be different on the problem machines. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
