From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from elvis.franken.de (elvis.franken.de [193.175.24.41]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D10FE1DFCF; Tue, 9 Jul 2024 15:46:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.175.24.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720540020; cv=none; b=p7WeIL/kw8p6HzwCEKcXKWFtXW0pW8bqsMAb4ivU8B9xCYfKgzs6NTVy6WWZFIbdiA8rMwba8n4zmaLZr/NjxhCTcAK5q3oU3lBfqHizBxmSDDYHT18XtxTEIUKAT8223WaI8Wk2ZAZZj+eDmpPevTJujV6yHHcVEjbWF9B1Q+Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720540020; c=relaxed/simple; bh=ioyj1azS+m2JjFteISlU9nXpPYH9cFxRj4zDAHSRCwg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mgyzvKohA6ApTMCGxiehjkVL4cBo1bhTmnm9XugoscMWDC3d533x9uUU3S/jFxPD+tNmZ35je+eB3HyvO9Xh/301dk/qqepAplZQb508eBo4IVTNZZo6SIauBhvbXh+1GGk+NEKDulvd2h39RD8VqUIV/k3kQqkiN5rHMiSwST8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=alpha.franken.de; spf=pass smtp.mailfrom=alpha.franken.de; arc=none smtp.client-ip=193.175.24.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=alpha.franken.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alpha.franken.de Received: from uucp by elvis.franken.de with local-rmail (Exim 3.36 #1) id 1sRD2h-0004Dh-00; Tue, 09 Jul 2024 17:46:11 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 42C22C031A; Tue, 9 Jul 2024 16:56:50 +0200 (CEST) Date: Tue, 9 Jul 2024 16:56:50 +0200 From: Thomas Bogendoerfer To: Daniel Lezcano Cc: Jiaxun Yang , Aleksandar Rikalo , Aleksandar Rikalo , Chao-ying Fu , Geert Uytterhoeven , Greg Ungerer , Hauke Mehrtens , Ilya Lipnitskiy , linux-kernel@vger.kernel.org, "linux-mips@vger.kernel.org" , Marc Zyngier , "paulburton@kernel.org" , Peter Zijlstra , Serge Semin , Thomas Gleixner , Tiezhu Yang Subject: Re: [PATCH v4 07/14] clocksource: mips-gic-timer: Always use cluster 0 counter as clocksource Message-ID: References: <20240511104341.151550-1-aleksandar.rikalo@syrmia.com> <20240511104341.151550-8-aleksandar.rikalo@syrmia.com> <8b133053-247f-414b-9c01-e0e5291e347d@app.fastmail.com> <4729a8ba-655d-4127-9f14-33b4521b4442@linaro.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4729a8ba-655d-4127-9f14-33b4521b4442@linaro.org> On Tue, Jul 09, 2024 at 04:44:30PM +0200, Daniel Lezcano wrote: > On 09/07/2024 10:53, Thomas Bogendoerfer wrote: > > On Tue, Jul 09, 2024 at 09:47:52AM +0800, Jiaxun Yang wrote: > > > > > > > > > 在2024年7月9日七月 上午12:36，Daniel Lezcano写道： > > > > On 11/05/2024 12:43, Aleksandar Rikalo wrote: > > > > > From: Paul Burton > > > > > > > > > > In a multi-cluster MIPS system we have multiple GICs - one in each > > > > > cluster - each of which has its own independent counter. The counters in > > > > > each GIC are not synchronised in any way, so they can drift relative to > > > > > one another through the lifetime of the system. This is problematic for > > > > > a clocksource which ought to be global. > > > > > > > > > > Avoid problems by always accessing cluster 0's counter, using > > > > > cross-cluster register access. This adds overhead so we only do so on > > > > > systems where we actually have CPUs present in multiple clusters. > > > > > For now, be extra conservative and don't use gic counter for vdso or > > > > > sched_clock in this case. > > > > > > > > > > Signed-off-by: Paul Burton > > > > > Signed-off-by: Chao-ying Fu > > > > > Signed-off-by: Dragan Mladjenovic > > > > > Signed-off-by: Aleksandar Rikalo > > > > > --- > > > > > > > > Applied patch 7 and 8 > > > > > > I think it won't compile without patch 1 being applid. > > > > > > Thomas, do you mind to apply patch 1 for now? Given that it's just some extra > > > function definitions. > > > > no problem, I've applied patch 1 und 2 to mips-next. > > Usually we create a shared immutable branch, but as we are close to the PR, > I propose I ack these two patches and let them go through the mips tree this > time works for me, as well. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]