On Tue, Jul 08, 2014 at 01:45:11PM -0700, Andrew Morton wrote: > > The user doesn't know or care about pte bits. > > What actually *happens*? Does criu migration hang? Does it lose data? > Does it take longer?
Ah, I see. Yes, the softdirty bit might be lost that usespace program won't see that a page was modified. So data lose is possible. > IOW, what would an end-user's bug report look like? > > It's important to think this way because a year from now some person > we've never heard of may be looking at a user's bug report and > wondering whether backporting this patch will fix it. Amongst other > reasons. Here is updated changelog, sounds better? --- In case if page fault happend on dirty filemapping the newly created pte may loose softdirty bit thus if a userspace program is tracking memory changes with help of a memory tracker (CONFIG_MEM_SOFT_DIRTY) it might miss modification of a memory page (which in worts case may lead to data inconsistency). -- 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/
