From patchwork Tue Jun 8 18:03:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12307871 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=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5CA84C47082 for ; Tue, 8 Jun 2021 18:10:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2317B61278 for ; Tue, 8 Jun 2021 18:10:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2317B61278 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-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5dMHKs17gcb3A99Kf3sqGcEqXrE7wuhIM045KGY12xc=; b=3gm3oKD5shtVai 9Qlvpy1Rem8cxZwrQelP4OHe73ONdwvFc+7LnfE1HaK4nBWpnkYoZxqA7Kogc38v+Yl4y8Bf4Uc92 FM2YWmHMpSsMAeSwT9WLbzkeXWizjxoK3VxX9koeyT7QTfMKbQZq/BeHOK7debQq2pW910w1odbHz fj1AlPVxL8v34uWRsj/+o0SLFzBt95KTlcdn8KS8CZzThbvJemL00HSSOIDeoq2pgziANSCXPcPdr ZtTWzZPQx9/r6haOHEjxAVoVZ7S88VshLg8zR7NrpR7QOCvH+c4fBNZa/rDwQnXDRouz+4yJmzLN8 p5x1yjN45DJKpResu60Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqg9W-009tEf-JJ; Tue, 08 Jun 2021 18:08:39 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lqg5A-009qx8-Cy for linux-arm-kernel@lists.infradead.org; Tue, 08 Jun 2021 18:04:10 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5EFA6613AC; Tue, 8 Jun 2021 18:04:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623175448; bh=KnO4RwnwsG9l1X2QI15v/pUtVxzDnZAWDHgdClkikTw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r0zJ/jft6E0o6XLT0wxVg/bCc4sscboKMt/VcQ8ws0L3Vj8/zsrOHH22jWc2pcxqV IrzQ3vjaM+V2jHB2xMsZhUAQBlqQo+U4/vBfW2wcrGXy727rSNWFNUkToKfPh9ZBHy eb1fWAUktQeG1aYdFchhOBA6GVLOi3IUIg7xoHOPwb4/yhL3IyOozRvIK8hQ1FbWw+ SpV9rrJG26tLhp0LIvYv90qd0eICWMMY1ulFxCVD+0We9JJ+aOwt+ucLYU3Ysvch7d r6zqBnaCpeXV1a9GHAMFEKh5DDuYbjqId3d4YzUDNCcrfkv6sYgRM92Xn2Bk9BAkNS 5IZGWJwR9kKqA== From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas , Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , Dietmar Eggemann , Daniel Bristot de Oliveira , Valentin Schneider , Mark Rutland , kernel-team@android.com, Valentin Schneider Subject: [PATCH v9 10/20] sched: Introduce task_struct::user_cpus_ptr to track requested affinity Date: Tue, 8 Jun 2021 19:03:03 +0100 Message-Id: <20210608180313.11502-11-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210608180313.11502-1-will@kernel.org> References: <20210608180313.11502-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210608_110408_520380_585463D1 X-CRM114-Status: GOOD ( 16.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In preparation for saving and restoring the user-requested CPU affinity mask of a task, add a new cpumask_t pointer to 'struct task_struct'. If the pointer is non-NULL, then the mask is copied across fork() and freed on task exit. Reviewed-by: Valentin Schneider Signed-off-by: Will Deacon --- include/linux/sched.h | 13 +++++++++++++ init/init_task.c | 1 + kernel/fork.c | 2 ++ kernel/sched/core.c | 20 ++++++++++++++++++++ 4 files changed, 36 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index d2c881384517..db32d4f7e5b3 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -730,6 +730,7 @@ struct task_struct { unsigned int policy; int nr_cpus_allowed; const cpumask_t *cpus_ptr; + cpumask_t *user_cpus_ptr; cpumask_t cpus_mask; void *migration_pending; #ifdef CONFIG_SMP @@ -1688,6 +1689,8 @@ extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_ #ifdef CONFIG_SMP extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); +extern int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node); +extern void release_user_cpus_ptr(struct task_struct *p); #else static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) { @@ -1698,6 +1701,16 @@ static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpuma return -EINVAL; return 0; } +static inline int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) +{ + if (src->user_cpus_ptr) + return -EINVAL; + return 0; +} +static inline void release_user_cpus_ptr(struct task_struct *p) +{ + WARN_ON(p->user_cpus_ptr); +} #endif extern int yield_to(struct task_struct *p, bool preempt); diff --git a/init/init_task.c b/init/init_task.c index 8b08c2e19cbb..158c2b1689e1 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -80,6 +80,7 @@ struct task_struct init_task .normal_prio = MAX_PRIO - 20, .policy = SCHED_NORMAL, .cpus_ptr = &init_task.cpus_mask, + .user_cpus_ptr = NULL, .cpus_mask = CPU_MASK_ALL, .nr_cpus_allowed= NR_CPUS, .mm = NULL, diff --git a/kernel/fork.c b/kernel/fork.c index dc06afd725cb..d3710e7f1686 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -446,6 +446,7 @@ void put_task_stack(struct task_struct *tsk) void free_task(struct task_struct *tsk) { + release_user_cpus_ptr(tsk); scs_release(tsk); #ifndef CONFIG_THREAD_INFO_IN_TASK @@ -918,6 +919,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #endif if (orig->cpus_ptr == &orig->cpus_mask) tsk->cpus_ptr = &tsk->cpus_mask; + dup_user_cpus_ptr(tsk, orig, node); /* * One for the user space visible state that goes away when reaped. diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 09fe20b3d6bb..f6ea3d7a07f2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2126,6 +2126,26 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) __do_set_cpus_allowed(p, new_mask, 0); } +int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, + int node) +{ + if (!src->user_cpus_ptr) + return 0; + + dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); + if (!dst->user_cpus_ptr) + return -ENOMEM; + + cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); + return 0; +} + +void release_user_cpus_ptr(struct task_struct *p) +{ + kfree(p->user_cpus_ptr); + p->user_cpus_ptr = NULL; +} + /* * This function is wildly self concurrent; here be dragons. *