From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261664AbTJML3Q (ORCPT ); Mon, 13 Oct 2003 07:29:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261678AbTJML3Q (ORCPT ); Mon, 13 Oct 2003 07:29:16 -0400 Received: from pentafluge.infradead.org ([213.86.99.235]:60562 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261664AbTJML3P (ORCPT ); Mon, 13 Oct 2003 07:29:15 -0400 Subject: Re: [RFC][PATCH] Kernel thread signal handling. From: David Woodhouse To: Russell King Cc: Andrew Morton , torvalds@osdl.org, linux-kernel@vger.kernel.org In-Reply-To: <20031013120843.E19601@flint.arm.linux.org.uk> References: <1066041096.24015.431.camel@hades.cambridge.redhat.com> <20031013040219.6ad71a57.akpm@osdl.org> <20031013120843.E19601@flint.arm.linux.org.uk> Content-Type: text/plain Message-Id: <1066044551.24015.455.camel@hades.cambridge.redhat.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-2.dwmw2.3) Date: Mon, 13 Oct 2003 12:29:12 +0100 Content-Transfer-Encoding: 7bit X-SA-Exim-Mail-From: dwmw2@infradead.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Pentafluge-Mail-From: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2003-10-13 at 12:08 +0100, Russell King wrote: > jffs2 is using signal handlers as a method of communicating from user > space to kernel space. Maybe it should create some sysfs files. > However, since there aren't any existing sysfs entities for jffs2 to > attach these files to, this wouldn't seem to be reasonable. To clarify -- the JFFS2 garbage collect thread is using SIGSTOP, SIGCONT and SIGKILL from userspace to mean exactly what SIGSTOP, SIGCONT and SIGKILL always mean in userspace. Since it already has signal handling code, we also use SIGHUP for wakeup, and userspace can send that too to trigger a single GC pass. -- dwmw2