From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id BA6246B005A for ; Mon, 16 Mar 2009 14:22:55 -0400 (EDT) Date: Mon, 16 Mar 2009 11:17:02 -0700 (PDT) From: Linus Torvalds Subject: Re: [aarcange@redhat.com: [PATCH] fork vs gup(-fast) fix] In-Reply-To: <200903170505.46905.nickpiggin@yahoo.com.au> Message-ID: References: <1237007189.25062.91.camel@pasglop> <200903170502.57217.nickpiggin@yahoo.com.au> <200903170505.46905.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Nick Piggin Cc: KOSAKI Motohiro , Benjamin Herrenschmidt , Andrea Arcangeli , Ingo Molnar , Nick Piggin , Hugh Dickins , KAMEZAWA Hiroyuki , linux-mm@kvack.org List-ID: On Tue, 17 Mar 2009, Nick Piggin wrote: > > If you disregard code motion and extra argument to copy_page_range, > my fix is a couple of dozen lines change to existing code, plus the > "decow" function (which could probably share a fair bit of code > with do_wp_page). > > Do you dislike the added complexity of the code? Or the behaviour > that gets changed? The complexity. That decow thing is shit. So is all the extra flags for no good reason. What's your argument against "keep it simple with a single lock, and adding basically a single line to reuse_swap_page() to say "don't reuse the page if the count is elevated"? THAT is simple and elegant, and needs none of the complexity. 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