On 04/29/2014 04:09 AM, Davidlohr Bueso wrote: > Adding Oleg. > > On Mon, 2014-04-28 at 14:55 -0700, Linus Torvalds wrote: >> On Mon, Apr 28, 2014 at 2:20 PM, Linus Torvalds >> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: >>> >>> That said, the bug does seem to be that some path doesn't invalidate >>> the vmacache sufficiently, or something inserts a vmacache entry into >>> the current process when looking up a remote process or whatever. >>> Davidlohr, ideas? >> >> Maybe we missed some use_mm() call. That will change the current mm >> without flushing the vma cache. The code considers kernel threads to >> be bad targets for vma caching for this reason (and perhaps others), >> but maybe we missed something. >> >> I wonder if we should just invalidate the vma cache in use_mm(), and >> remote the "kernel tasks are special" check. >> >> Srivatsa, are you doing something peculiar on that system that would >> trigger this? I see some kdump failures in the log, anything else? > > Is this perhaps a KVM guest? fwiw I see CONFIG_KVM_ASYNC_PF=y which is a > user of use_mm(). > No, this is just running baremetal on x86. I copied the kernel config of a distro kernel and reused it. Regards, Srivatsa S. Bhat -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>