From patchwork Thu May 19 10:52:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12854780 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77A5BC433F5 for ; Thu, 19 May 2022 10:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236971AbiESKwq (ORCPT ); Thu, 19 May 2022 06:52:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234382AbiESKwn (ORCPT ); Thu, 19 May 2022 06:52:43 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C68C6C0DF for ; Thu, 19 May 2022 03:52:39 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 5500C1F86A; Thu, 19 May 2022 10:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1652957558; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=76k9iwtB764AkBR/gy2UDaYc9U3MSwSK6w0czfIl2Rc=; b=nB9q5ey4Uti0xC9hsDRP1Q4LGIDLndtlvIEvPaqFUd81QfszqRAzFX9dIL1GRwhPY06Pq7 w1yuykz84bYgjSL/HwImoDZFZQg7mJXjH0KJYksZO1mpcw2LeuMV8BKpMHsH5o3cQdPMl7 p+GzMk05h4CjFcT37VREbXeFkavBRHo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1652957558; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=76k9iwtB764AkBR/gy2UDaYc9U3MSwSK6w0czfIl2Rc=; b=TCkj1+NqHhWTJKF+zoUYf7hfoZlTys4H+ipsAnmtS4Lf78HeoirznnuDhveZUnZED6Mrhy W86hhGxXc/h0tLBg== Received: from quack3.suse.cz (unknown [10.100.224.230]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 44BCC2C141; Thu, 19 May 2022 10:52:38 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 704E6A062F; Thu, 19 May 2022 12:52:35 +0200 (CEST) From: Jan Kara To: Paolo Valente Cc: , Jens Axboe , Jan Kara Subject: [PATCH 0/4] bfq: Improve waker detection Date: Thu, 19 May 2022 12:52:28 +0200 Message-Id: <20220519104621.15456-1-jack@suse.cz> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=723; h=from:subject:message-id; bh=dgid7zJjnf7k5rGKo9h8dIAbPk1Iz4zwPoMAY/VKEmg=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBihiFahICwwaM+wdhYIkprN/VQHRVeNixXxpNHD1az QUktbtGJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYoYhWgAKCRCcnaoHP2RA2XeIB/ oCw+YEX/s63DtkTsrQhu27L5p7dqLYIA7G2z5zw//rVM27ojgDH8q47W0EgmTmEeAIwuu9wEJSyacC VBFLhdmTPgiVB0otdLXdmgTRUgVXtBZ7SYObc6q5lR9q3uejIv/8Xo4JhDkhjWjPYtzfnqNPnmyoxX BarVXQB3end5QFTdlcvx8bVTrIX7aRmTGPF9vhqmBwqgyxBtuaSgixl6MP/ZBxVo6A4kPw+Vp6Aa8/ AeZh6hdIg1DEzvPu72Jd2mchI6OMiktauMZ1zda5ORCCPInrrj68Fqgil12pDq/ZkL3SDmibdbNhYQ 5RoRgbBZDNSwVhEaKUguBwEMsJF2JE X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, this patch series restores regression in dbench for large number of processes that was introduced by c65e6fd460b4 ("bfq: Do not let waker requests skip proper accounting"). The detailed explanation is in the first patch but the culprit in the end was that with large number of dbench clients it often happened that flush worker bfqq replaced jbd2 bfqq as a waker of the bfqq shared by dbench clients and that resulted in lot of idling and reduced throughput. The first two patches in this series improve the waker detection, the other two are just cleanups I've spotted when working on the code. I've tested the patches and they don't seem to cause regression for other workloads. Honza