From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946525AbXD3RRv (ORCPT ); Mon, 30 Apr 2007 13:17:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946532AbXD3RRv (ORCPT ); Mon, 30 Apr 2007 13:17:51 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:49769 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1946525AbXD3RRu (ORCPT ); Mon, 30 Apr 2007 13:17:50 -0400 Date: Mon, 30 Apr 2007 18:21:35 +0100 From: Alan Cox To: Andrew Morton Cc: "Robert P. J. Day" , Linux Kernel Mailing List Subject: Re: can a kmalloc be both GFP_ATOMIC and GFP_KERNEL at the same time? Message-ID: <20070430182135.0fae7b89@the-village.bc.nu> In-Reply-To: <20070430100225.353e3030.akpm@linux-foundation.org> References: <20070430001311.84d0291f.akpm@linux-foundation.org> <20070430100225.353e3030.akpm@linux-foundation.org> X-Mailer: Claws Mail 2.9.1 (GTK+ 2.10.8; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > > > drivers/scsi/aic7xxx_old.c: aic_dev = kmalloc(sizeof(struct aic_dev_data), GFP_ATOMIC | GFP_KERNEL); > > > > drivers/message/i2o/device.c: resblk = kmalloc(buflen + 8, GFP_KERNEL | GFP_ATOMIC); > > > > > > > > clarification? > > > > > > GFP_ATOMIC implies that the memory comes from the zones which > > > GFP_KERNEL also uses. So the above usage of GFP_KERNEL is redundant > > > and should be removed. > > > > hang on ... based on an email i just got, is that reference to > > GFP_KERNEL "redundant" or "conflicting"? big difference there. and > > is the proper fix to remove "GFP_KERNEL" in both cases? > > > > umm, yeah, oops. GFP_KERNEL|GFP_ATOMIC is not a redundant combination. > It's GFP_KERNEL plus "is able to access emergency pools". We'd normally > represent that as GFP_KERNEL|__GFP_HIGH. i2o/device.c should be GFP_KERNEL as far as I can tell. It was meant to be that way and the callers appear to all be calling it in sleep capable contexts. aic7xxx_old.c should probably be GFP_KERNEL as ->slave_alloc methods appear to be able to sleep (although some drivers use GFP_ATOMIC here and some GFP_KERNEL). Alan