On Fri, Oct 26, 2012 at 11:14 AM, Rik van Riel <r...@redhat.com> wrote: > > I suspect the next context switch would flush out the TLB, > making it a slowdown, not a lockup.
Common case, yes. But the page fault might happen in kernel space (due to a "put_user()" call, say), and with CONFIG_PREEMPT=n. Sure, put_user() is always done in a context where blocking (and scheduling) is legal, but that doesn't necessarily equate scheduling actually happening. If we're returning to kernel space and don't have any IO, it might never happen. Anyway, I suspect such behavior it's almost impossible to trigger. Which would just make it rather hard to find. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/