From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx173.postini.com [74.125.245.173]) by kanga.kvack.org (Postfix) with SMTP id 58ACC6B004A for ; Sun, 18 Mar 2012 18:01:30 -0400 (EDT) Received: by wgbds10 with SMTP id ds10so522091wgb.26 for ; Sun, 18 Mar 2012 15:01:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20120318190744.GA6589@ZenIV.linux.org.uk> References: <20120318190744.GA6589@ZenIV.linux.org.uk> From: Linus Torvalds Date: Sun, 18 Mar 2012 15:01:08 -0700 Message-ID: Subject: Re: [rfc][patches] fix for munmap/truncate races Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Al Viro Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org On Sun, Mar 18, 2012 at 12:07 PM, Al Viro wrote: > - =A0 =A0 =A0 tlb_finish_mmu(&tlb, 0, end); > + =A0 =A0 =A0 tlb_finish_mmu(&tlb, 0, -1); Hmm. The fact that you drop the end pointer means that some architectures that optimize the TLB flushing for ranges now effectively can't do it any more. Now, I think it's only ia64 that really is affected, but it *might* matter. In particular, ia64 has some logic for "if you only flush one single region, you can optimize it", and the region sizes are in the terabytes. And I'm pretty sure you broke that - I'm just not entirely sure how much we care. 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org