From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755858AbYICNle (ORCPT ); Wed, 3 Sep 2008 09:41:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754910AbYICNlQ (ORCPT ); Wed, 3 Sep 2008 09:41:16 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:60083 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754676AbYICNlP (ORCPT ); Wed, 3 Sep 2008 09:41:15 -0400 Date: Wed, 3 Sep 2008 15:41:05 +0200 From: Sebastien Dugue To: benh@kernel.crashing.org Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, paulus@samba.org, michael@ellerman.id.au, jean-pierre.dion@bull.net, gilles.carry@ext.bull.net, tinytim@us.ibm.com, tglx@linutronix.de, rostedt@goodmis.org, dwalker@mvista.com Subject: Re: [PATCH 2/2] powerpc - Make the irq reverse mapping radix tree lockless Message-ID: <20080903154105.7dff49db@bull.net> In-Reply-To: <1219209781.21386.25.camel@pasglop> References: <1218029429-21114-1-git-send-email-sebastien.dugue@bull.net> <1218029429-21114-3-git-send-email-sebastien.dugue@bull.net> <1219209781.21386.25.camel@pasglop> X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.2; 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, 20 Aug 2008 15:23:01 +1000 Benjamin Herrenschmidt wrote: > BTW. It would be good to try to turn the GFP_ATOMIC into GFP_KERNEL, That would be nice indeed > maybe using a semaphore instead of a lock to protect insertion vs. > initialisation. a semaphore? are you meaning a mutex? If not, I fail to understand what you're implying. > The old scheme was fine because if the atomic allocation > failed, it could fallback to the linear search and try again on the next > interrupt. Not anymore. Right, that's the problem with this new scheme and I'm still trying to find a way to handle memory allocation failures be it for GFP_ATOMIC or GFP_KERNEL. I could not think of anything simple so far and I'm open for suggestions. Thanks, Sebastien.