From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 16 Jun 2004 11:51:55 -0500 From: Dimitri Sivanich Subject: Re: [PATCH]: Option to run cache reap in thread mode Message-ID: <20040616165155.GA6069@sgi.com> References: <20040616142413.GA5588@sgi.com> <20040616160355.GA5963@sgi.com> <20040616160714.GA14413@infradead.org> <200406161225.11946.jbarnes@engr.sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200406161225.11946.jbarnes@engr.sgi.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Jesse Barnes Cc: Christoph Hellwig , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Wed, Jun 16, 2004 at 12:25:11PM -0400, Jesse Barnes wrote: > On Wednesday, June 16, 2004 12:07 pm, Christoph Hellwig wrote: > > Well, if you want deterministic interrupt latencies you should go for a > > realtime OS. > > Although I don't want to see another kernel thread added as much as the next > guy, I think that minimizing the amount of time that irqs are turned off is > probably a good thing in general. For example, the patch to allow interrupts > in spin_lock_irq if the lock is already taken is generally a really good > thing, because even though reducing lock contention should be a goal, locks > by their very nature are taken sometimes, and allowing other CPUs to get > useful work done while they're waiting for it is obviously desirable. > > > I know Linux is the big thing in the industry, but you're > > really better off looking for a small Hard RT OS. > > Sure, for some applications, an RTOS is necessary. But it seems like keeping > latencies down in Linux is a good thing to do nonetheless. > > Can you think of other ways to reduce the length of time that interrupts are > disabled during cache reaping? It seems like the cache_reap loop might be a > candidate for reorganization (though that would probably imply other > changes). I have another patch forthcoming that does some reorganizing of the locking. With the two patches I see substantial improvement. > > Thanks, > Jesse -- 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/ . Don't email: aart@kvack.org