From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964916AbWDGTmx (ORCPT ); Fri, 7 Apr 2006 15:42:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964919AbWDGTmx (ORCPT ); Fri, 7 Apr 2006 15:42:53 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:43483 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S964916AbWDGTmw (ORCPT ); Fri, 7 Apr 2006 15:42:52 -0400 Subject: Re: [PATCH 2/4] coredump: speedup SIGKILL sending From: Lee Revell To: Oleg Nesterov Cc: Andrew Morton , "Eric W. Biederman" , Ingo Molnar , "Paul E. McKenney" , Roland McGrath , linux-kernel@vger.kernel.org In-Reply-To: <20060407232838.GA11460@oleg> References: <20060406220628.GA237@oleg> <1144352758.2866.105.camel@mindpipe> <20060406235519.GA331@oleg> <1144354065.2866.116.camel@mindpipe> <20060407232838.GA11460@oleg> Content-Type: text/plain Date: Fri, 07 Apr 2006 15:42:47 -0400 Message-Id: <1144438967.22490.90.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.6.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2006-04-08 at 03:28 +0400, Oleg Nesterov wrote: > zap_process() disables irqs while traversing ->thread_group list. > So yes, if a process has a lot of threads it will be a latency regression. > (but again, __group_complete_signal() does the same while delivering this > signal, so I don't think this change can make things worse). > > However this allows us to avoid tasklist_lock in zap_threads() so I think > it is worth it. Please note that tasklist_lock was held while iterating > over _all_ threads in system, not only current's thread group. > OK sounds good. Lee