On Sat, 2014-03-08 at 12:02 -0800, Linus Torvalds wrote: > On Sat, Mar 8, 2014 at 11:44 AM, Oleg Nesterov <o...@redhat.com> wrote: > > > > Sure. But another thread or CLONE_VM task can do vmacache_invalidate(), > > hit vmacache_seqnum == 0 and call vmacache_flush_all() to solve the > > problem with potential overflow. > > How? > > Any invalidation is supposed to hold the mm semaphore for writing. And > we should have it for reading.
Yes, invalidations are always with the write lock held. In any case it's a good candidate to use verify_mm_writelocked(), even if it's only under debug environments. -- 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/
