From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 21 Aug 2005 20:48:54 -0700 (PDT) From: Linus Torvalds Subject: Re: [PATCH] Use deltas to replace atomic inc In-Reply-To: Message-ID: References: <20050817151723.48c948c7.akpm@osdl.org> <20050817174359.0efc7a6a.akpm@osdl.org> <20050818212939.7dca44c3.akpm@osdl.org> <20050820005843.21ba4d9b.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andrew Morton , hugh@veritas.com, nickpiggin@yahoo.com.au, linux-mm@kvack.org List-ID: On Sun, 21 Aug 2005, Christoph Lameter wrote: > > The thing that bothers me more is that schedule() can be called both by > handle_mm_fault as well as during unuse_mm. We may need some flag > PF_NO_COUNTER_UPDATES or so there to insure that schedule() does not add > deltas to the current->mm. Why? I don't think it's ever wrong to do the thing. We should be holding no locks at the point (and we haven't grabbed he RQ lock yet), so it should always be safe to get the page table lock. I think the delta approach looks quite reasonable, although I think somebody should check that the cache behaviour is ok (ie the deltas should hopefully be in a cacheline that we need to look at anyway). Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org