From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C976D441D; Wed, 4 Sep 2024 14:28:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725460128; cv=none; b=JcL8tUE7rBjxd3cnZboIQxi/HclSvGctTZMvfojJgmng47sB1YRe1qfATvQ6BRAy919Iv9jKF4k51NSc9elXIPdA2XNgPpVVYfDidooDkG3Z1ShBa5xN5GU2oq8YeyEEpj1pGzq1hPWip9r0p5jLQ37qKfVcjvAc6JBWVplQoak= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725460128; c=relaxed/simple; bh=h6qi7OJYw6lw0d+g19EW35P5d3ez9MJ76mD+ej0r9Cs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ridpcKZxtLgeQPnRwh5llhfonaR30kg4IaiJsIVe4IMi4i4BCQc0BTyf3ytq2Hq8Y/P8c3tQ0rrnZ33LhdTTNXR+jWM7ZYmOQvO/rF1a6Qj91IYau9rfKPzLKDlCsdB9S2kX8qjmpafUdR9pcctGC4T7xIRGi5rtWjrnnO6hSYw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Vl08D1AY; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Vl08D1AY" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=u40QMF5x2NUW5Y4tWOwtilkkruVYCjqBSAXZKvLFW1U=; b=Vl08D1AYrLZZWnAJoLaDlc5SEh 9aPXO+j4zGwAveF7A6NLNsFSmRyku+iRI9CoNrmiNHyEZFjHVGIS1748iqvK/QHPoO+LAjvqcm8Su RjfBxAfg1luMdkH+++spDLNop8zv4Br9vPF9DESskBxcAz8o7hODQcIcbTX2UDpeCS8YC0ugUeCWJ 6DX7m2h9ULJEkAHv/0W1nt/h19q7Fww8cqIGlv0H5gDi/UcVC36/FnPFiIWTnvE0l02Jq9I0/inBV ZllDz+ixDM7WJpGjD8VH5pXQf4Rmc07mST3Og/kQ3LkXZGj3fQccnf3zeDiySw6XRlNfjlZu6HpAz u8udRsNQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1slqzy-00000000FUG-1yLs; Wed, 04 Sep 2024 14:28:43 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id D4DA4300642; Wed, 4 Sep 2024 16:28:41 +0200 (CEST) Date: Wed, 4 Sep 2024 16:28:41 +0200 From: Peter Zijlstra To: Jens Axboe Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, rafael@kernel.org, daniel.lezcano@linaro.org, linux-pm@vger.kernel.org Subject: Re: [PATCHSET v6 0/4] Split iowait into two states Message-ID: <20240904142841.GL4723@noisy.programming.kicks-ass.net> References: <20240819154259.215504-1-axboe@kernel.dk> 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=us-ascii Content-Disposition: inline In-Reply-To: <20240819154259.215504-1-axboe@kernel.dk> On Mon, Aug 19, 2024 at 09:39:45AM -0600, Jens Axboe wrote: > Hi, > > This is v6 of the patchset where the current in_iowait state is split > into two parts: > > 1) The "task is sleeping waiting on IO", and would like cpufreq goodness > in terms of sleep and wakeup latencies. > 2) The above, and also accounted as such in the iowait stats. > > The current ->in_iowait covers both, this series splits it into two types > of state so that each can be controlled seperately. Yeah, but *WHY* !?!? I have some vague memories from last time around, but patches should really keep this information. > Patches 1..3 are prep patches, changing the type of > task_struct->nr_iowait and adding helpers to manipulate the iowait counts. > > Patch 4 does the actual splitting. > > This has been sitting for a while, would be nice to get this queued up > for 6.12. Comments welcome! Ufff, and all this because menu-governor does something insane :-( Rafael, why can't we simply remove this from menu? All the nr_iowait*() users are basically broken and I would much rather fix broken rather than work around broken like this. That is, from where I'm sitting this all makes the io-wait situation far worse instead of better.