From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754952Ab0FXLLG (ORCPT ); Thu, 24 Jun 2010 07:11:06 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:59423 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754932Ab0FXLLD convert rfc822-to-8bit (ORCPT ); Thu, 24 Jun 2010 07:11:03 -0400 Subject: Re: [RFC][PATCH] irq_work From: Peter Zijlstra To: Andi Kleen Cc: Huang Ying , Ingo Molnar , "H.PeterA" <"nvin hpa"@zytor.com>, linux-kernel@vger.kernel.org In-Reply-To: <20100624110830.GC578@basil.fritz.box> References: <1277362243.3947.20.camel@yhuang-dev.sh.intel.com> <1277362680.1875.845.camel@laptop> <1277363069.3947.30.camel@yhuang-dev.sh.intel.com> <1277363993.1875.847.camel@laptop> <1277364453.3947.64.camel@yhuang-dev.sh.intel.com> <1277364727.1875.857.camel@laptop> <20100624102725.GA578@basil.fritz.box> <1277375409.1875.943.camel@laptop> <20100624105254.GB578@basil.fritz.box> <1277377121.1875.948.camel@laptop> <20100624110830.GC578@basil.fritz.box> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 24 Jun 2010 13:10:52 +0200 Message-ID: <1277377852.1875.950.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2010-06-24 at 13:08 +0200, Andi Kleen wrote: > > And I really want hardirq context for perf callbacks, some code actually > > relies on it (I used to have the fallback in the timer softirq and that > > Surely that could be fixed? *requiring* hard irq context sounds weird. possibly, but there is no reason what so ever to use softirq here. > > broke thing at some point). > > I have one case that needs to sleep (but only when interrupting user code) > They key thing in it really is to switch stacks back to process. softirq can't sleep either, you need a trampoline anyway.