On Mon, 2007-08-20 at 14:50 -0700, Christoph Lameter wrote: > One of the problems with reclaim writeout is that it occurs when memory in a > zone is low. A particular bad problem can occur if memory in a zone is > already low and now the first page that we encounter during reclaim is dirty. > So the writeout function is called without the filesystem or device having > much of a reserve that would allow further allocations. Triggering writeout > of dirty pages early does not improve the memory situation since the actual > writeout of the page is a relatively long process. The call to writepage > will therefore not improve the low memory situation but make it worse > because extra memory may be needed to get the device to write the page. > > This patchset fixes that issue by: > > 1. First reclaiming non dirty pages. Dirty pages are deferred until reclaim > has reestablished the high marks. Then all the dirty pages (the laundry) > is written out. > > 2. Reclaim is essentially complete during the writeout phase. So we remove > PF_MEMALLOC and allow recursive reclaim if we still run into trouble > during writeout.
This almost insta-OOMs with anonymous workloads. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
