Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755079AbbFLHXK (ORCPT ); Fri, 12 Jun 2015 03:23:10 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:34219 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546AbbFLHXH (ORCPT ); Fri, 12 Jun 2015 03:23:07 -0400 Date: Fri, 12 Jun 2015 09:23:02 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Linux Kernel Mailing List , linux-mml@vger.kernel.org, Andy Lutomirski , Andrew Morton , Denys Vlasenko , Brian Gerst , Peter Zijlstra , Borislav Petkov , "H. Peter Anvin" , Oleg Nesterov , Thomas Gleixner , Waiman Long Subject: Re: [PATCH 07/12] x86/virt/guest/xen: Remove use of pgd_list from the Xen guest code Message-ID: <20150612072302.GA7509@gmail.com> References: <1434031637-9091-1-git-send-email-mingo@kernel.org> <1434031637-9091-8-git-send-email-mingo@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1108 Lines: 32 * Linus Torvalds wrote: > On Thu, Jun 11, 2015 at 1:37 PM, Linus Torvalds > wrote: > > > > Don't use "for_each_process_thread(g, p)". You only care about each mm, and > > threads all share the same mm, so just do > > > > for_each_process(p) > > > > instead of iterating over all threads too. > > Hmm. I may be wrong. It strikes me that one of the group leaders might have > exited but the subthreads live on. We'd see p->mm being NULL, even though the mm > was originally in use. > > Ugh. So maybe the code really does need to iterate over all threads. Yeah, for_each_process() is indeed no guarantee that we iterate over all mm's. We might make it so: but that would mean restricting certain clone_flags variants - not sure that's possible with our current ABI usage? Thanks, 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/