Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261981AbVEEAm0 (ORCPT ); Wed, 4 May 2005 20:42:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261982AbVEEAm0 (ORCPT ); Wed, 4 May 2005 20:42:26 -0400 Received: from alog0211.analogic.com ([208.224.220.226]:43433 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S261981AbVEEAmV (ORCPT ); Wed, 4 May 2005 20:42:21 -0400 Date: Wed, 4 May 2005 20:42:07 -0400 (EDT) From: "Richard B. Johnson" Reply-To: linux-os@analogic.com To: Alex Riesen cc: Olivier Croquette , LKML Subject: Re: Scheduler: SIGSTOP on multi threaded processes In-Reply-To: <81b0412b0505041406297427ba@mail.gmail.com> Message-ID: References: <4279084C.9030908@free.fr> <20050504191604.GA29730@nevyn.them.org> <81b0412b0505041406297427ba@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1720 Lines: 42 On Wed, 4 May 2005, Alex Riesen wrote: > On 5/4/05, Daniel Jacobowitz wrote: >> On Wed, May 04, 2005 at 02:16:24PM -0400, Richard B. Johnson wrote: >>> The kernel doesn't do SIGSTOP or SIGCONT. Within init, there is >>> a SIGSTOP and SIGCONT handler. These can be inherited by others >>> unless changed, perhaps by a 'C' runtime library. Basically, >>> the SIGSTOP handler executes pause() until the SIGCONT signal >>> is received. >>> >>> Any delay in stopping is the time necessary for the signal to >>> be delivered. It is possible that the section of code that >>> contains the STOP/CONT handler was paged out and needs to be >>> paged in before the signal can be delivered. >>> >>> You might quicken this up by installing your own handler for >>> SIGSTOP and SIGCONT.... >> >> I don't know what RTOSes you've been working with recently, but none of >> the above is true for Linux. I don't think it ever has been. >> > > I don't even think it was true for anything. It's his usual way of > saying things. > Nope, I thought he was talking about the terminal stopper/starter, SIGTSTP used for X-ON and X-OFF. I thought he was sending that signal, timing it, then restarting with SIGCONT. You can't restart or even trap a SIGSTOP signal. Cheers, Dick Johnson Penguin : Linux version 2.6.11 on an i686 machine (5537.79 BogoMips). Notice : All mail here is now cached for review by Dictator Bush. 98.36% of all statistics are fiction. - 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/