Messages in this thread | | | From | Nick Piggin <> | Subject | Re: VM/VFS bug with large amount of memory and file systems? | Date | Tue, 18 Sep 2007 03:12:31 +1000 |
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On Tuesday 18 September 2007 03:04, Rik van Riel wrote: > Nick Piggin wrote: > > (Rik has a patch sitting in -mm I believe which would make this problem > > even worse, by doing even less highmem scanning in response to lowmem > > allocations). > > My patch should not make any difference here, since > balance_pgdat() already scans the zones from high to > low and sets an end_zone variable that determines the > highest zone to scan. > > All my patch does is make sure that we do not try to > reclaim excessive amounts of dma or low memory when > a higher zone is full.
Sorry, yeah I had it the wrong way around. Your patch would not increase the probability of this problem.
We could have some logic in there to scan highmem when buffer heads are over limit. But that really kind of sucks in that it introduces some arbitrary point where reclaim behaviour completely changes... Adding a shrinker for buffer heads is the "logical" approach that we take for other non-page caches. That also kind of sucks because we normally don't want to do this out of band buffer reclaiming and just have it work from page reclaim (it will introduce extra locking and list scanning).
Maybe when the machine is near OOM, we can just change the scanning to do all zones -- a change in scanning behaviour at that point is better than oom kill. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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