From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: 2.5.40-mm2 From: Robert Love In-Reply-To: <3DA0B422.C23B23D4@digeo.com> References: <3DA0854E.CF9080D7@digeo.com> <3DA0A144.8070301@us.ibm.com> <3DA0B151.6EF8C8D9@digeo.com> <3DA0B422.C23B23D4@digeo.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: 06 Oct 2002 18:23:40 -0400 Message-Id: <1033943021.27093.29.camel@phantasy> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Dave Hansen , lkml , "linux-mm@kvack.org" , Ingo Molnar List-ID: On Sun, 2002-10-06 at 18:07, Andrew Morton wrote: > > - while (base->running_timer == timer) { > > + while (base->running_timer == timer) > > cpu_relax(); > > - preempt_disable(); > > - preempt_enable(); I am confused as to why Ingo would put these here. He knows very well what he is doing... surely he had a reason. If he intended to force a preemption point here, then the lines needs to be reversed. This assumes, of course, preemption is disabled here. But I do not think it is. If he just wanted to check for preemption, we have a preempt_check_resched() which does just that (I even think he wrote it). Note as long as interrupts are enabled this probably does not achieve much anyhow. So I do not know. I find it odd the solution is to completely remove it... Btw, I think the solution to the crash is to add a check to cpu_online(). Robert Love -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/