On Sun, Sep 30, 2018 at 06:28:21PM +0800, zhong jiang wrote: > From: Alexey Dobriyan <adobriyan@xxxxxxxxx> > > [ Upstream commit e5d9998f3e09359b372a037a6ac55ba235d95d57 ] > > /* > * cpu_partial determined the maximum number of objects > * kept in the per cpu partial lists of a processor. > */ > > Can't be negative. > > I hit a real issue that it will result in a large number of memory leak. > Becuase Freeing slabs are in interrupt context. So it can trigger this issue. > put_cpu_partial can be interrupted more than once. > due to a union struct of lru and pobjects in struct page, when other core handles > page->lru list, for eaxmple, remove_partial in freeing slab code flow, It will > result in pobjects being a negative value(0xdead0000). Therefore, a large number > of slabs will be added to per_cpu partial list. > > I had posted the issue to community before. The detailed issue description is as follows. > > https://www.spinics.net/lists/kernel/msg2870979.html > > After applying the patch, The issue is fixed. So the patch is a effective bugfix. > It should go into stable. > > Link: http://lkml.kernel.org/r/20180305200730.15812-15-adobriyan@xxxxxxxxx > Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> > Acked-by: Christoph Lameter <cl@xxxxxxxxx> > Cc: Pekka Enberg <penberg@xxxxxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> # 4.4.x This didn't apply to 4.14.y and any reason you didn't cc: the stable mailing list for the other stable developers to see it? I've fixed up the patch, but next time please always cc: the stable list. thanks, greg k-h
