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=-9.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 BC53FC169D4 for ; Wed, 14 Nov 2018 02:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8147022513 for ; Wed, 14 Nov 2018 02:46:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="houvQSdY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8147022513 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732316AbeKNMri (ORCPT ); Wed, 14 Nov 2018 07:47:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:51522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731854AbeKNMri (ORCPT ); Wed, 14 Nov 2018 07:47:38 -0500 Received: from lerouge.suse.de (lfbn-ncy-1-241-207.w83-194.abo.wanadoo.fr [83.194.85.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4386A2243E; Wed, 14 Nov 2018 02:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542163588; bh=19WkyUkboSZyfb9685TeeAVHMmQCKTfx25fgEa3jisI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=houvQSdYSSYO77mZUQ2F5sGCdKKKvp874T1QN3MHY5snuhuR7VQqKjjaFJ+RcYyb1 ckwRpoYOzceu1MpXuEnX1YdWEbKg2SPT6SaPM7ux5b/Whchmtv0gO2fOjl/Br/5Ri7 o5KQP8Bydil70zDmaDG6dhM/JNQ1bwTXaE/B5tOk= From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Peter Zijlstra , Wanpeng Li , Thomas Gleixner , Yauheni Kaliuta , Ingo Molnar , Rik van Riel Subject: [PATCH 05/25] sched/vtime: Record CPU under seqcount for kcpustat needs Date: Wed, 14 Nov 2018 03:45:49 +0100 Message-Id: <1542163569-20047-6-git-send-email-frederic@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1542163569-20047-1-git-send-email-frederic@kernel.org> References: <1542163569-20047-1-git-send-email-frederic@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to compute the kcpustat delta on a nohz CPU, we'll need to fetch the task running on that target. Checking that its vtime state snapshot actually refers to the relevant target involves recording that CPU under the seqcount locked on task switch. This is a step toward making kcpustat moving forward on full nohz CPUs. Signed-off-by: Frederic Weisbecker Cc: Yauheni Kaliuta Cc: Thomas Gleixner Cc: Rik van Riel Cc: Peter Zijlstra Cc: Wanpeng Li Cc: Ingo Molnar --- include/linux/sched.h | 1 + kernel/sched/cputime.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index a51c13c..9f56880 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -275,6 +275,7 @@ struct vtime { seqcount_t seqcount; unsigned long long starttime; enum vtime_state state; + unsigned int cpu; u64 utime; u64 stime; u64 gtime; diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index facc665..6ac27687 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -817,6 +817,7 @@ void vtime_task_switch_generic(struct task_struct *prev) else __vtime_account_kernel(prev, vtime); vtime->state = VTIME_INACTIVE; + vtime->cpu = -1; write_seqcount_end(&vtime->seqcount); vtime = ¤t->vtime; @@ -824,6 +825,7 @@ void vtime_task_switch_generic(struct task_struct *prev) write_seqcount_begin(&vtime->seqcount); vtime->state = VTIME_SYS; vtime->starttime = sched_clock(); + vtime->cpu = smp_processor_id(); write_seqcount_end(&vtime->seqcount); } @@ -836,6 +838,7 @@ void vtime_init_idle(struct task_struct *t, int cpu) write_seqcount_begin(&vtime->seqcount); vtime->state = VTIME_SYS; vtime->starttime = sched_clock(); + vtime->cpu = cpu; write_seqcount_end(&vtime->seqcount); local_irq_restore(flags); } -- 2.7.4