Re: [patch] 'virtual => physical page mapping cache', vcache-2.5.38-B8

From: Ingo Molnar (mingo@elte.hu)
Date: Fri Sep 27 2002 - 12:44:08 EST


and i'm not quite sure how other users of get_user_pages() (direct-IO)
handle these kinds of COW races. A COW can invalidate a physical page
anytime, so the DMA might go to the fork()ed child process, creating very
unexpected results. We are protected against kswapd via the elevated page
count, but are not protected against COW.

        Ingo

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon Sep 30 2002 - 22:00:32 EST