From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 16 May 2002 11:56:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 16 May 2002 11:56:07 -0400 Received: from bgp401130bgs.jersyc01.nj.comcast.net ([68.36.96.125]:36365 "EHLO buggy.badula.org") by vger.kernel.org with ESMTP id ; Thu, 16 May 2002 11:56:07 -0400 Date: Thu, 16 May 2002 11:55:00 -0400 Message-Id: <200205161555.g4GFt0v05623@buggy.badula.org> From: Ion Badulescu To: Bart Trojanowski Cc: linux-kernel@vger.kernel.org Subject: Re: Q: x86 interrupt arrival after cli In-Reply-To: <20020515202720.D15996@jukie.net> User-Agent: tin/1.5.11-20020130 ("Toxicity") (UNIX) (Linux/2.4.18 (i586)) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 15 May 2002 20:27:20 -0400, Bart Trojanowski wrote: > [-- text/plain, encoding quoted-printable, 14 lines --] > > Quick question for the x86 gurus: > > If a hardware interrupt arrives within a spin_lock_irqsave & > spin_unlock_irqrestore will the interrupt handler associated with said > interrupt be called immediately after the spinlock is released? > > I am interested in any delays, even those less then a jiffie. The interrupt will occur when the instruction after the "sti" finishes. That's a one assembler instruction delay, i.e. a few clock cycles. *Which* interrupt will be serviced first, however, depends on how many interrupt sources you have active and on the IRQ prioritization. Ion -- It is better to keep your mouth shut and be thought a fool, than to open it and remove all doubt.