Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754807AbYGVMsN (ORCPT ); Tue, 22 Jul 2008 08:48:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751386AbYGVMr6 (ORCPT ); Tue, 22 Jul 2008 08:47:58 -0400 Received: from nf-out-0910.google.com ([64.233.182.189]:1367 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbYGVMr6 (ORCPT ); Tue, 22 Jul 2008 08:47:58 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=vqEUS+JviyoIfKnVqMzpy6b2hwOukq8Mwp1cJXLkD7U2UjV+V9pXWz9XvHAocCOwVT 87F6uNbGwYK6sVufKGgVa7eNuVBtAyuhoqJH343smWD5jkBGtmnGefyElpiuSEZ7Jnkj yJekph3h5GV/wZJBFuz6niOgZJcvcwvC89mws= Message-ID: Date: Tue, 22 Jul 2008 14:47:56 +0200 From: "Michael Kerrisk" To: "Oleg Nesterov" Subject: Re: [PATCH -mm] coredump: format_corename: don't append .%pid if multi-threaded Cc: "Alan Cox" , "Roland McGrath" , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, andi@firstfloor.org In-Reply-To: <20080722124314.GA3267@tv-sign.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200807210137.m6L1bN0H011138@imap1.linux-foundation.org> <20080721102940.666d733d@the-village.bc.nu> <20080721210121.C5E741541A5@magilla.localdomain> <20080721221416.6d4f9014@lxorguk.ukuu.org.uk> <20080722113731.GA1383@tv-sign.ru> <20080722121824.GB1383@tv-sign.ru> <20080722124314.GA3267@tv-sign.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1940 Lines: 48 On Tue, Jul 22, 2008 at 2:43 PM, Oleg Nesterov wrote: > On 07/22, Michael Kerrisk wrote: >> >> On Tue, Jul 22, 2008 at 2:18 PM, Oleg Nesterov wrote: >> > If the coredumping is multi-threaded, format_corename() appends .%pid >> > to the corename. This was needed before the proper multi-thread core >> > dump support, now all the threads in the mm go into a single unified >> > core file. >> > >> > Remove this special case, it is not even documented and we have "%p" >> > and core_uses_pid. >> >> Hi Oleg, >> >> I have not thought about this at any length, but one question that >> jumps to mind: could this feature still be useful for LinuxThreads, >> where each thread does indeed have a separate PID? > > As far as I know, LinuxThreads use CLONE_VM, right? Yes. > The coredump will create the single core file for all processes because > they have the same ->mm, the "threads" won't dump all over each other. Yes, looks like you are right. I had this vague idea that there were circumstances where a dump of a LinuxThreads m-t process could produce multipl core files, distinguished by the .PID, but I think I must have misremembered. > And, just in case, this patch doesn't make any difference if core_uses_pid > is set or pid_in_pattern is true. > > That said, this is the user-visible change... True. Not sure how important that is in this case though. What is the reason for making this change (other than tidiness)? -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html -- 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/