On Fri, Jun 8, 2012 at 2:19 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 8 Jun 2012 13:23:56 -0700 > Pravin Shelar <pshelar@xxxxxxxxxx> wrote: > >> On Fri, Jun 8, 2012 at 1:15 PM, Christoph Lameter <cl@xxxxxxxxx> wrote: >> > On Fri, 8 Jun 2012, Andrew Morton wrote: >> > >> >> OK. __I assume this bug has been there for quite some time. >> > >> > Well the huge pages refcount tricks caused the issue. >> > >> >> How serious is it? __Have people been reporting it in real workloads? >> >> How to trigger it? __IOW, does this need -stable backporting? >> > >> > Possibly. >> >> If this patch is getting back-ported then we shld also do same for >> 5bf5f03c271907978 (mm: fix slab->page flags corruption) which fixes >> other issue related to slub and huge page sharing. > > Well I don't know if either are getting backported yet. > > To decide that we would have to understand the end-user impact of the > bug(s). Please tell us? > We are working on zero copy io over skb in Open-vswitch. thats when we so this panic when we tried to get_page() over skb linear data allocated slub. But then I realized that it could potentially affect other subsystems as well, e.g. xfs and ocfs, which does page struct updates on slub objects. -- 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/ . Don't email: <a href