From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [PATCH][RFC]: mutex: adaptive spin Date: Tue, 6 Jan 2009 08:11:41 -0800 (PST) Message-ID: References: <1230722935.4680.5.camel@think.oraclecorp.com> <20081231104533.abfb1cf9.akpm@linux-foundation.org> <1230765549.7538.8.camel@think.oraclecorp.com> <87r63ljzox.fsf@basil.nowhere.org> <20090103191706.GA2002@parisc-linux.org> <1231093310.27690.5.camel@twins> <20090104184103.GE2002@parisc-linux.org> <1231242031.11687.97.camel@twins> <20090106121052.GA27232@elte.hu> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Peter Zijlstra , Matthew Wilcox , Andi Kleen , Chris Mason , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel , linux-btrfs , Thomas Gleixner , Steven Rostedt , Gregory Haskins , Nick Piggin To: Ingo Molnar Return-path: In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 6 Jan 2009, Linus Torvalds wrote: > > The other way around, you mean: we spin until the owner is no longer > holding a cpu. Btw, I hate the name of the helper function for that. "task_is_current()"? "current" means something totally different in the linux kernel: it means that the task is _this_ task. So the only sensible implementation of "task_is_current(task)" is to just make it return "task == current", but that's obviously not what the function wants to do. So it should be renamed. Something like "task_is_oncpu()" or whatever. I realize that the scheduler internally has that whole "rq->curr" thing, but that's an internal scheduler thing, and should not be confused with the overall kernel model of "current". Linus