Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751345AbWCNQpv (ORCPT ); Tue, 14 Mar 2006 11:45:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752045AbWCNQpv (ORCPT ); Tue, 14 Mar 2006 11:45:51 -0500 Received: from mailout1.vmware.com ([65.113.40.130]:33548 "EHLO mailout1.vmware.com") by vger.kernel.org with ESMTP id S1751345AbWCNQpu (ORCPT ); Tue, 14 Mar 2006 11:45:50 -0500 Message-ID: <4416F30D.3040403@vmware.com> Date: Tue, 14 Mar 2006 08:45:01 -0800 From: Zachary Amsden User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: Zwane Mwaikambo Cc: Linux Kernel Mailing List Subject: Re: VMI Interface Proposal Documentation for I386, Part 5 References: <4415CE76.9030006@vmware.com> <44167E03.3060807@vmware.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1501 Lines: 33 Zwane Mwaikambo wrote: > Hello Zach, > > On Tue, 14 Mar 2006, Zachary Amsden wrote: > > >> It could be possible to change the semantics of the interrupt masking >> interface in Linux, such that enable_interrupts() did just that - but did not >> yet deliver pending IRQs. As did restore_interrupt_mask(). This would >> require inspection of many drivers to ensure that they don't rely on those >> actions causing immediate interrupt delivery. And if they did, they would >> require a call, say, deliver_pending_irqs() to accomplish that. >> > > I think we can break these down into low level and higher level interrupt > enabling. Lower level tends to be call sites like exception entry, in that > particular case drivers aren't aware of the interrupt enable/disable > semantics so it's safe to enable without dispatch. Higher up is where > dispatch makes sense and we can closer mimick hardware. > Yes, there may clearly be a benefit to having a low level / high level separation - say STI / PUSHF / POPF, and EnableInterrupts, SaveInterruptFlag, RestoreInterruptFlag. I didn't want to do that yet, since it adds bulk to the interface, but there clearly is some value there. And as you point out, it does save a driver audit. Zach - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/