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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7F8FBC433ED for ; Thu, 22 Apr 2021 12:39:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4670961164 for ; Thu, 22 Apr 2021 12:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236121AbhDVMjj (ORCPT ); Thu, 22 Apr 2021 08:39:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236326AbhDVMiF (ORCPT ); Thu, 22 Apr 2021 08:38:05 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EE28C06174A for ; Thu, 22 Apr 2021 05:37:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=RN2xAIABvOnqEJsdwF8TfHxkP9RCd0zxgZN5JQF4LOw=; b=lZAII9l4B5HwyMFZ+xBYtMHb/S TlZvCzKqZXXSJbkqzY67/MaeHBWOOgMFLwaOSJzXOK7DXLRblNWBpi5LTQ9b0IgCx1/YxIAeYNsQE UGuAaU8T0LEbXdla6jB5ZH4sdXrqdqtMPgJTLfxO0FHFpr1vn3x18Up7NiyfziWjL6Me9pMn3KFbu kf0c5iWORlUfjygUOS1GKjQ3r5oi76XwzI7arnYqM7vUzQZmKskYs/nOM/Wlq/sa+tFCQBKfmAHCD 5gSpAExKdWWZZYy6FXhmxiWZOqFdsQknCDmqARsBsOA1LVTBRPldZHGaQSGavyFAbc/7nXLzhd36s 8PdX32ZQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lZYZM-000IDb-T2; Thu, 22 Apr 2021 12:36:36 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 81F6930032A; Thu, 22 Apr 2021 14:35:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 776B42C67A906; Thu, 22 Apr 2021 14:35:20 +0200 (CEST) Message-ID: <20210422123308.980003687@infradead.org> User-Agent: quilt/0.66 Date: Thu, 22 Apr 2021 14:05:16 +0200 From: Peter Zijlstra To: joel@joelfernandes.org, chris.hyser@oracle.com, joshdon@google.com, mingo@kernel.org, vincent.guittot@linaro.org, valentin.schneider@arm.com, mgorman@suse.de Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de Subject: [PATCH 17/19] sched: Inherit task cookie on fork() References: <20210422120459.447350175@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Note that sched_core_fork() is called from under tasklist_lock, and not from sched_fork() earlier. This avoids a few races later. Signed-off-by: Peter Zijlstra (Intel) --- include/linux/sched.h | 2 ++ kernel/fork.c | 3 +++ kernel/sched/core_sched.c | 6 ++++++ 3 files changed, 11 insertions(+) --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2172,8 +2172,10 @@ const struct cpumask *sched_trace_rd_spa #ifdef CONFIG_SCHED_CORE extern void sched_core_free(struct task_struct *tsk); +extern void sched_core_fork(struct task_struct *p); #else static inline void sched_core_free(struct task_struct *tsk) { } +static inline void sched_core_fork(struct task_struct *p) { } #endif #endif --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2249,6 +2249,8 @@ static __latent_entropy struct task_stru klp_copy_process(p); + sched_core_fork(p); + spin_lock(¤t->sighand->siglock); /* @@ -2336,6 +2338,7 @@ static __latent_entropy struct task_stru return p; bad_fork_cancel_cgroup: + sched_core_free(p); spin_unlock(¤t->sighand->siglock); write_unlock_irq(&tasklist_lock); cgroup_cancel_fork(p, args); --- a/kernel/sched/core_sched.c +++ b/kernel/sched/core_sched.c @@ -100,6 +100,12 @@ static unsigned long sched_core_clone_co return cookie; } +void sched_core_fork(struct task_struct *p) +{ + RB_CLEAR_NODE(&p->core_node); + p->core_cookie = sched_core_clone_cookie(current); +} + void sched_core_free(struct task_struct *p) { sched_core_put_cookie(p->core_cookie);