From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (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 4CB3114A0A9; Thu, 25 Apr 2024 14:20:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714054834; cv=none; b=qhxclAy2dmau+mh+MqIUFSabjOcXA3aegLJXFRVSS4hH/OI/RE3LNPpEzGQMbw5zw40IDoNPXvOpOj01/CqjmlR/RbA4fMsHInZEwCRkVRV9SdbYQZffFL4rUXOYL9muPZDDVVxzTJ7rDf/NfyoMNxODXkdpJP6u1g9Pf93Z4EY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714054834; c=relaxed/simple; bh=JekMetg/YF071aOgGl/DrEuzh3d8IGL9N+wrQlKfEO8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QREqstlpPuZz6XToXezUAY06ahm63XI0bqh5JI/78f33VDYnoxIMSLamgps6bBHFdMEUZcXGwwAe6scWsUOJuFPR/XlOYog1DmFun0EF8irHlFxGOkTxvfpo672KH2w+2fUb9XbNgtTYMLOiH6bEsXQC3KyNVZQT2rh9fOni+o8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=fail (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=ini0VbyF reason="signature verification failed"; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="ini0VbyF" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 6.0.0) id 05c7b55a3e2687dd; Thu, 25 Apr 2024 16:20:30 +0200 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id AFECE66DF01; Thu, 25 Apr 2024 16:20:29 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1714054830; bh=JekMetg/YF071aOgGl/DrEuzh3d8IGL9N+wrQlKfEO8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ini0VbyF7UvGBKz+HxzK+fk/fRgbPxizJ+PdVeO+Tdw11egMVG0nhZXUhg5H8BQHf ZsdNyYWSjoL9rrMEYCLoO9Hg4Prf28sHrML1iS2AItLw7opD840kfjFBPD+Yq9ZCCV gdDnbO70s6Ymtmjr8J9w42lgToFRjyGmrfmw2f7yU0HASKMAAKZaPifs2EVTlxhouR F1Awtj8RGdQOgnFzT/z7s5xQIfCtTR7Ygh0O/RZseekMnnKkeU4GThowGQZBv3p3OU TIQy0EXga+T6ROHadsqzdXKl9rjQoUtcbEUJeFIr3gOKgGH/Tk41etN/Z9uCXlQ8wP nxkcnFSJ6YZAg== From: "Rafael J. Wysocki" To: Jens Axboe , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, linux-pm@vger.kernel.org, daniel.lezcano@linaro.org, "Rafael J. Wysocki" Subject: Re: [PATCH 4/4] sched/core: split iowait state into two states Date: Thu, 25 Apr 2024 16:20:29 +0200 Message-ID: <8409301.NyiUUSuA9g@kreacher> In-Reply-To: <20240424100127.GV40213@noisy.programming.kicks-ass.net> References: <20240416121526.67022-1-axboe@kernel.dk> <20240416121526.67022-5-axboe@kernel.dk> <20240424100127.GV40213@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="UTF-8" X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvledrudeljedgjeehucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppeduleehrddufeeirdduledrleegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepudelhedrudefiedrudelrdelgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohepjedprhgtphhtthhopegrgigsohgvsehkvghrnhgvlhdrughkpdhrtghpthhtohepphgvthgvrhiisehinhhfrhgruggvrggurdhorhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepthhglhigsehlihhnuhhtrhhonhhigidruggvpdhrtghpthhtoheplhhinhhugidqphhmsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepuggrnhhivghlrdhlvgiitggrnhhosehlihhnrghrohdrohhrgh X-DCC--Metrics: v370.home.net.pl 1024; Body=7 Fuz1=7 Fuz2=7 On Wednesday, April 24, 2024 12:01:27 PM CEST Peter Zijlstra wrote: > On Tue, Apr 16, 2024 at 06:11:21AM -0600, Jens Axboe wrote: > > iowait is a bogus metric, but it's helpful in the sense that it allows > > short waits to not enter sleep states that have a higher exit latency > > than would've otherwise have been picked for iowait'ing tasks. However, > > it's harmless in that lots of applications and monitoring assumes that > > iowait is busy time, or otherwise use it as a health metric. > > Particularly for async IO it's entirely nonsensical. > > Let me get this straight, all of this is about working around > cpuidle menu governor insaity? > > Rafael, how far along are we with fully deprecating that thing? Yes it > still exists, but should people really be using it still? Well, they appear to be used to it ...