From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id A70A46B0047 for ; Mon, 16 Mar 2009 14:29:20 -0400 (EDT) From: Nick Piggin Subject: Re: [aarcange@redhat.com: [PATCH] fork vs gup(-fast) fix] Date: Tue, 17 Mar 2009 05:29:08 +1100 References: <1237007189.25062.91.camel@pasglop> <200903170502.57217.nickpiggin@yahoo.com.au> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200903170529.08995.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org To: Linus Torvalds Cc: KOSAKI Motohiro , Benjamin Herrenschmidt , Andrea Arcangeli , Ingo Molnar , Nick Piggin , Hugh Dickins , KAMEZAWA Hiroyuki , linux-mm@kvack.org List-ID: On Tuesday 17 March 2009 05:14:59 Linus Torvalds wrote: > On Tue, 17 Mar 2009, Nick Piggin wrote: > > What part of that do you dislike, though? I don't think the lock is a > > particularly elegant idea either (shared cacheline, vmsplice, converting > > callers). > > All of the absolute *crap* for no good reason. > > Did you even look at your patch? It wasn't as ugly as Andrea's, but it was > ugly enough, and it was buggy. That whole "decow" stuff was too f*cking > ugly to live. What's buggy about it? Stupid bugs, or fundamentally broken? > Couple that with the fact that no real-life user can possibly care, and > that O_DIRECT is broken to begin with, and I say: "let's fix this with a > _much_ smaller patch". If it is based on nobody caring, I would prefer not to add anything at all to "fix" it? We have MADV_DONTFORK already... > You may think that the lock isn't particularly "elegant", but I can only > say "f*ck that, look at the number of lines of code, and the simplicity". > > Your "elegant" argument is total and utter sh*t, in other words. The lock > approach is tons more elegant, considering that it solves the problem much > more cleanly, and with _much_ less crap. In my opinion it is not, given that you have to convert callers. If you say that you only care about fixing O_DIRECT, then yes I would probably agree the lock is nicer in that case. -- 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