From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764379AbYDNSym (ORCPT ); Mon, 14 Apr 2008 14:54:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756357AbYDNSyb (ORCPT ); Mon, 14 Apr 2008 14:54:31 -0400 Received: from fk-out-0910.google.com ([209.85.128.186]:44803 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758579AbYDNSya (ORCPT ); Mon, 14 Apr 2008 14:54:30 -0400 Message-ID: <4803A85F.2080603@colorfullife.com> Date: Mon, 14 Apr 2008 20:54:23 +0200 From: Manfred Spraul User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Nadia Derbey CC: Peter Zijlstra , efault@gmx.de, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org, xemul@openvz.org Subject: Re: [PATCH 00/13] Re: Scalability requirements for sysv ipc References: <20080411161702.460410000@bull.net> <1207931235.7157.0.camel@twins> <4802E93E.4090205@bull.net> <1208157359.7427.25.camel@twins> <480316D3.7070901@bull.net> In-Reply-To: <480316D3.7070901@bull.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nadia Derbey wrote: > > Well, 1 interface changes, 1 is added and another one went away: > > 1) for the preload part (it becomes like the radix-tree preload part): > > int idr_pre_get(struct idr *, gfp_t); > would become > int idr_pre_get(gfp_t); > Btw, that's one point I didn't understand about the idr code: Is it interrupt-safe? It uses spin_lock_irqsave and gfp_t, this implies that it could be called from all contexts. But the prealloc made me a bit nervous: does it handle idr_pre_get(); interrupt with another idr_pre_get(), add, pre_get_end, interrupt ends, ... correctly? If it's only intended to be called from process context I would remove the _irqsave and perhaps add an assert(!in_interrupt()) -- Manfred