On 08/23/2012 03:56 PM, Minchan Kim wrote: > Hi Seth, > > On Thu, Aug 23, 2012 at 10:33:09AM -0500, Seth Jennings wrote: >> This patchset fixes a regression in 3.6 by reverting two dependent >> commits that made changes to zcache_do_preload(). >> >> The commits undermine an assumption made by tmem_put() in >> the cleancache path that preemption is disabled. This change >> introduces a race condition that can result in the wrong page >> being returned by tmem_get(), causing assorted errors (segfaults, >> apparent file corruption, etc) in userspace. >> >> The corruption was discussed in this thread: >> https://lkml.org/lkml/2012/8/17/494 > > I think changelog isn't enough to explain what's the race. > Could you write it down in detail? I didn't come upon this solution via code inspection, but rather through discovering that the issue didn't exist in v3.5 and just looking at the changes since then. > And you should Cc'ed Xiao who is author of reverted patch. Thanks for adding Xiao. I meant to do this. For some reason I thought that you submitted that patchset :-/ My bad. Seth -- 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>