From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CDBCC433E0 for ; Sat, 8 Aug 2020 23:39:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3703B20791 for ; Sat, 8 Aug 2020 23:39:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596929957; bh=/yMoRiL9K4k2IOgMxROgkfrtKFe7hZ5Taf1cht6du7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TyMrZyYVIv+iU4LvKiFGUH4V0xgktato+7MNJuoP5qYtSG9o1kH7X7krSnek/hy4S MEZzZb3Zjyd6u8e/zgg1VbcyJq+luowFxl/G1DQK/GFmIv1FXT7mr/ITwVqJ5EEOli 94ZRjwWbki6OS4X3Zel2QpkQ9MkzFQYq7xl9Ed8o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728502AbgHHXjP (ORCPT ); Sat, 8 Aug 2020 19:39:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:53574 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728464AbgHHXjF (ORCPT ); Sat, 8 Aug 2020 19:39:05 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BE85320829; Sat, 8 Aug 2020 23:39:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596929944; bh=/yMoRiL9K4k2IOgMxROgkfrtKFe7hZ5Taf1cht6du7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LEfqRVmCkJKHNl9bYJY/Vqr6ynsgY/EQtyhkC7aego5CIfQz5pCpx4KBU4eBv1Dbz qoHrUmsuXEO53pY28RPFF2SdaQZOL0OnwHL0xx/emBlwQiAXcsH8BWGK08W5LlHlY8 gHPGyVUm7PBOmvMUzjUJRjFpkfEEfxAM0m7GhEAY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Qais Yousef , Peter Zijlstra , Valentin Schneider , Lukasz Luba , Sasha Levin Subject: [PATCH AUTOSEL 5.4 15/40] sched/uclamp: Fix initialization of struct uclamp_rq Date: Sat, 8 Aug 2020 19:38:19 -0400 Message-Id: <20200808233844.3618823-15-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200808233844.3618823-1-sashal@kernel.org> References: <20200808233844.3618823-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Qais Yousef [ Upstream commit d81ae8aac85ca2e307d273f6dc7863a721bf054e ] struct uclamp_rq was zeroed out entirely in assumption that in the first call to uclamp_rq_inc() they'd be initialized correctly in accordance to default settings. But when next patch introduces a static key to skip uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil will fail to perform any frequency changes because the rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which means all rqs are capped to 0 by default. Fix it by making sure we do proper initialization at init without relying on uclamp_rq_inc() doing it later. Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting") Signed-off-by: Qais Yousef Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Valentin Schneider Tested-by: Lukasz Luba Link: https://lkml.kernel.org/r/20200630112123.12076-2-qais.yousef@arm.com Signed-off-by: Sasha Levin --- kernel/sched/core.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 38ae3cf9d173e..b34b5c6e25248 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1238,6 +1238,20 @@ static void uclamp_fork(struct task_struct *p) } } +static void __init init_uclamp_rq(struct rq *rq) +{ + enum uclamp_id clamp_id; + struct uclamp_rq *uc_rq = rq->uclamp; + + for_each_clamp_id(clamp_id) { + uc_rq[clamp_id] = (struct uclamp_rq) { + .value = uclamp_none(clamp_id) + }; + } + + rq->uclamp_flags = 0; +} + static void __init init_uclamp(void) { struct uclamp_se uc_max = {}; @@ -1246,11 +1260,8 @@ static void __init init_uclamp(void) mutex_init(&uclamp_mutex); - for_each_possible_cpu(cpu) { - memset(&cpu_rq(cpu)->uclamp, 0, - sizeof(struct uclamp_rq)*UCLAMP_CNT); - cpu_rq(cpu)->uclamp_flags = 0; - } + for_each_possible_cpu(cpu) + init_uclamp_rq(cpu_rq(cpu)); for_each_clamp_id(clamp_id) { uclamp_se_set(&init_task.uclamp_req[clamp_id], -- 2.25.1