From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758490AbZBZWSU (ORCPT ); Thu, 26 Feb 2009 17:18:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753469AbZBZWSF (ORCPT ); Thu, 26 Feb 2009 17:18:05 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:36984 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753224AbZBZWSC (ORCPT ); Thu, 26 Feb 2009 17:18:02 -0500 Date: Thu, 26 Feb 2009 14:16:32 -0800 From: Andrew Morton To: Frank Seidel Cc: linux-kernel@vger.kernel.org, linux-isdn@vger.kernel.org, fseidel@suse.de, frank@f-seidel.de, jolly@eversberg.eu, kkeil@suse.de, smurf@smurf.noris.de, andreas@eversberg.eu, hannes@hanneseder.net Subject: Re: [PATCH][trivial] mISDN: l1oip - reduce stack memory footprint Message-Id: <20090226141632.6e3c041d.akpm@linux-foundation.org> In-Reply-To: <49A569D0.2070705@suse.de> References: <49A569D0.2070705@suse.de> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 25 Feb 2009 16:54:56 +0100 Frank Seidel wrote: > From: Frank Seidel > > Applying kernel janitors todos (reduce stack > footprint where possible) to l1oip mISDN driver. > (Before 1656 bytes on i386, now 164) > > Signed-off-by: Frank Seidel > --- > drivers/isdn/mISDN/l1oip_core.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > --- a/drivers/isdn/mISDN/l1oip_core.c > +++ b/drivers/isdn/mISDN/l1oip_core.c > @@ -663,18 +663,28 @@ l1oip_socket_thread(void *data) > struct iovec iov; > mm_segment_t oldfs; > struct sockaddr_in sin_rx; > - unsigned char recvbuf[1500]; > + unsigned char *recvbuf; > + size_t recvbuf_size = 1500; > int recvlen; > struct socket *socket = NULL; > DECLARE_COMPLETION(wait); > > + /* allocate buffer memory */ > + recvbuf = kmalloc(recvbuf_size * sizeof(*recvbuf), GFP_KERNEL); It's rather pointless to multiply by sizeof(*recvbuf) here > - iov.iov_len = sizeof(recvbuf); > + iov.iov_len = recvbuf_size; > oldfs = get_fs(); > set_fs(KERNEL_DS); > - recvlen = sock_recvmsg(socket, &msg, sizeof(recvbuf), 0); > + recvlen = sock_recvmsg(socket, &msg, recvbuf_size, 0); but not here.