From nobody Mon Jun 8 17:39:47 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9B67427A0C for ; Wed, 27 May 2026 15:38:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896334; cv=none; b=WwjRaTW3XmY8lk2ks3CxGI8GUZgVhxUrEhxBT+bNiom6nyuH/xAxGfNWPRJSxaBTjEX0k0FOvsYkmwLk6PTRO9RgLnl0Dgaf3LwZua75nn14SGd/uQtAUCB1EGcHnGSVxro7pYPeGBiTAr0icKeSTMfGEB4YQ/FyiwtLQM5Do1o= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896334; c=relaxed/simple; bh=ja8QwMW/mmlNgmqfj0hBpJdp841yTjdEA77sLJvBLk0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o+5l8H6S+StL++elXQ1k0kqDIQLX3ATIklI5i+3QpA5wFhRde2NTkiXyOa2VlP2B2uECb/dWuIw3BFc66oNWH+3nlTDxk0x0xFEA0sM0B99/icfWGu7oNPQvXNPvhx+wzmYG0u8BfbuTmyxwnRjk93Weajk4chNykHKwLUwTnTw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Dp76Nrsw; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Dp76Nrsw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779896331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tdylMAS/gkAyE0POz57Y8ng1h9gF+KWnXVKL0TsaNFQ=; b=Dp76Nrswd/RUuRXvgjqTO65+oH6MTHprq3ZW2KnWIcrPWVXYPS23eo71JhDCgTAWg7wlTn pJgJmBGYwqXcBMc+/1va4gR55HjSvVATKuQQV+4ahw7J/Ch/FacjRbTbyCyDzXnVhNPxdZ rJVy4pPARIphcAlompr8pGRUnGAyUV4= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-646-Ds-_atucNM2ea22E4Shkkw-1; Wed, 27 May 2026 11:38:47 -0400 X-MC-Unique: Ds-_atucNM2ea22E4Shkkw-1 X-Mimecast-MFC-AGG-ID: Ds-_atucNM2ea22E4Shkkw_1779896326 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E04CC18002F0; Wed, 27 May 2026 15:38:45 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.81.53]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B4D3B1800576; Wed, 27 May 2026 15:38:43 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Waiman Long Subject: [PATCH-next v3 1/5] cgroup/cpuset: Add a cpuset_reserve_dl_bw() helper Date: Wed, 27 May 2026 11:37:56 -0400 Message-ID: <20260527153800.1557449-2-longman@redhat.com> In-Reply-To: <20260527153800.1557449-1-longman@redhat.com> References: <20260527153800.1557449-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Extract the DL bandwidth allocation code in cpuset_attach() to a new cpuset_reserve_dl_bw() helper to simplify code. No functional change is expected. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 53 ++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 23 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 51327333980a..d720bcc7ef83 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2980,6 +2980,25 @@ static int cpuset_can_attach_check(struct cpuset *cs) return 0; } =20 +static int cpuset_reserve_dl_bw(struct cpuset *cs) +{ + int cpu, ret; + + if (!cs->sum_migrate_dl_bw) + return 0; + + cpu =3D cpumask_any_and(cpu_active_mask, cs->effective_cpus); + if (unlikely(cpu >=3D nr_cpu_ids)) + return -EINVAL; + + ret =3D dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); + if (ret) + return ret; + + cs->dl_bw_cpu =3D cpu; + return 0; +} + static void reset_migrate_dl_data(struct cpuset *cs) { cs->nr_migrate_dl_tasks =3D 0; @@ -2994,7 +3013,7 @@ static int cpuset_can_attach(struct cgroup_taskset *t= set) struct cpuset *cs, *oldcs; struct task_struct *task; bool setsched_check; - int cpu, ret; + int ret; =20 /* used later by cpuset_attach() */ cpuset_attach_old_cs =3D task_cs(cgroup_taskset_first(tset, &css)); @@ -3050,31 +3069,19 @@ static int cpuset_can_attach(struct cgroup_taskset = *tset) } } =20 - if (!cs->sum_migrate_dl_bw) - goto out_success; - - cpu =3D cpumask_any_and(cpu_active_mask, cs->effective_cpus); - if (unlikely(cpu >=3D nr_cpu_ids)) { - ret =3D -EINVAL; - goto out_unlock; - } - - ret =3D dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); - if (ret) - goto out_unlock; - - cs->dl_bw_cpu =3D cpu; - -out_success: - /* - * Mark attach is in progress. This makes validate_change() fail - * changes which zero cpus/mems_allowed. - */ - cs->attach_in_progress++; + ret =3D cpuset_reserve_dl_bw(cs); =20 out_unlock: - if (ret) + if (ret) { reset_migrate_dl_data(cs); + } else { + /* + * Mark attach is in progress. This makes validate_change() fail + * changes which zero cpus/mems_allowed. + */ + cs->attach_in_progress++; + } + mutex_unlock(&cpuset_mutex); return ret; } --=20 2.54.0 From nobody Mon Jun 8 17:39:47 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9694B42EED9 for ; Wed, 27 May 2026 15:38:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896337; cv=none; b=bhmHMPQWZRszKvvuRDx0OXqCTQtof/Hra16wvckn6md4g9/CkfkJ8hwPhFgM8M7JXqJE6tOpKuUQl9HcMtFsKbzPq/1sUpbIL+qkId5JwCJ6+QnU076XyHnroBcdCcPU8RKj54YwdXQVizWFBvijld8izIFU2s19/4duPeDRLhU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896337; c=relaxed/simple; bh=vXaHGpo/cOpKoi25nWttdUbf6C9e0+GWhw1wTzmdFDc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RzQCOFmPEWvc0J5m/nRXiB5akcbBb8ikPUi9c52+JTJrDGVKRPgcguS1j98oXLjWDQEMONrm1+4eyHbpMcWf2AXc2K4+WGZcdt6mgSCLaB+Yr5a13XYe8s7ABgKwCJrv5Xq0MbjMSns1LMWwM83vXPV+WeowdJz28pg1hK90sow= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=itilgD80; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="itilgD80" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779896333; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l7MH3OtjWXO3O907SYH4/EiI2G1a5AP5AYerCApbaVM=; b=itilgD80YTcbOeKyMuLATDzHQQzsULjDdyFUCCajpo1Jz2mRxK/YYrcdLcKEg9t0jlPdu8 Ty1ks5KBHVBoEc6uhx4f83qS9QxV8YLtap534Ee1gSBvHdDTqSaoZvutCEB4qArhpQGcO6 Zj3n9l2a7yD2em+ywaxDCHlhyybBMAY= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-679-kxy6W9r-OXG8Mbocx97J9w-1; Wed, 27 May 2026 11:38:49 -0400 X-MC-Unique: kxy6W9r-OXG8Mbocx97J9w-1 X-Mimecast-MFC-AGG-ID: kxy6W9r-OXG8Mbocx97J9w_1779896328 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id ACB051956096; Wed, 27 May 2026 15:38:47 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.81.53]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 20D961800465; Wed, 27 May 2026 15:38:46 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Waiman Long Subject: [PATCH-next v3 2/5] cgroup/cpuset: Expand the scope of cpuset_can_attach_check() Date: Wed, 27 May 2026 11:37:57 -0400 Message-ID: <20260527153800.1557449-3-longman@redhat.com> In-Reply-To: <20260527153800.1557449-1-longman@redhat.com> References: <20260527153800.1557449-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Expand the scope of cpuset_can_attach_check() by including the setting of setsched flag inside cpuset_can_attach_check() with the new @oldcs and @psetsched argument. As cpuset_can_attach_check() is also called from cpuset_can_fork(), set the new arguments to NULL from that caller. While at it, expose the source and destination cpuset cpu/memory check results in the new attach_cpus_updated and attach_mems_updated static flags so that these flags can be used directly from cpuset_attach() without the need to do the same computations again. No functional change is expected. Reviewed-by: Chen Ridong Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 70 +++++++++++++++++++++++++----------------- 1 file changed, 42 insertions(+), 28 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index d720bcc7ef83..4457c4f11fce 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2964,19 +2964,56 @@ static int update_prstate(struct cpuset *cs, int ne= w_prs) return 0; } =20 +/* + * cpuset_can_attach() and cpuset_attach() specific internal data + * Protected by cpuset_mutex + */ static struct cpuset *cpuset_attach_old_cs; +static bool attach_cpus_updated; +static bool attach_mems_updated; =20 /* * Check to see if a cpuset can accept a new task * For v1, cpus_allowed and mems_allowed can't be empty. * For v2, effective_cpus can't be empty. * Note that in v1, effective_cpus =3D cpus_allowed. + * + * Also set the boolean flag passed in by @psetsched depending on if + * security_task_setscheduler() call is needed and @oldcs is not NULL. */ -static int cpuset_can_attach_check(struct cpuset *cs) +static int cpuset_can_attach_check(struct cpuset *cs, struct cpuset *oldcs, + bool *psetsched) { if (cpumask_empty(cs->effective_cpus) || (!is_in_v2_mode() && nodes_empty(cs->mems_allowed))) return -ENOSPC; + + if (!oldcs) + return 0; + + /* + * Update attach specific data + */ + attach_cpus_updated =3D !cpumask_equal(cs->effective_cpus, oldcs->effecti= ve_cpus); + attach_mems_updated =3D !nodes_equal(cs->effective_mems, oldcs->effective= _mems); + + /* + * Skip rights over task setsched check in v2 when nothing changes, + * migration permission derives from hierarchy ownership in + * cgroup_procs_write_permission()). + */ + *psetsched =3D !cpuset_v2() || attach_cpus_updated || attach_mems_updated; + + /* + * A v1 cpuset with tasks will have no CPU left only when CPU hotplug + * brings the last online CPU offline as users are not allowed to empty + * cpuset.cpus when there are active tasks inside. When that happens, + * we should allow tasks to migrate out without security check to make + * sure they will be able to run after migration. + */ + if (!is_in_v2_mode() && cpumask_empty(oldcs->effective_cpus)) + *psetsched =3D false; + return 0; } =20 @@ -3023,29 +3060,10 @@ static int cpuset_can_attach(struct cgroup_taskset = *tset) mutex_lock(&cpuset_mutex); =20 /* Check to see if task is allowed in the cpuset */ - ret =3D cpuset_can_attach_check(cs); + ret =3D cpuset_can_attach_check(cs, oldcs, &setsched_check); if (ret) goto out_unlock; =20 - /* - * Skip rights over task setsched check in v2 when nothing changes, - * migration permission derives from hierarchy ownership in - * cgroup_procs_write_permission()). - */ - setsched_check =3D !cpuset_v2() || - !cpumask_equal(cs->effective_cpus, oldcs->effective_cpus) || - !nodes_equal(cs->effective_mems, oldcs->effective_mems); - - /* - * A v1 cpuset with tasks will have no CPU left only when CPU hotplug - * brings the last online CPU offline as users are not allowed to empty - * cpuset.cpus when there are active tasks inside. When that happens, - * we should allow tasks to migrate out without security check to make - * sure they will be able to run after migration. - */ - if (!is_in_v2_mode() && cpumask_empty(oldcs->effective_cpus)) - setsched_check =3D false; - cgroup_taskset_for_each(task, css, tset) { ret =3D task_can_attach(task); if (ret) @@ -3140,7 +3158,6 @@ static void cpuset_attach(struct cgroup_taskset *tset) struct cgroup_subsys_state *css; struct cpuset *cs; struct cpuset *oldcs =3D cpuset_attach_old_cs; - bool cpus_updated, mems_updated; bool queue_task_work =3D false; =20 cgroup_taskset_first(tset, &css); @@ -3148,9 +3165,6 @@ static void cpuset_attach(struct cgroup_taskset *tset) =20 lockdep_assert_cpus_held(); /* see cgroup_attach_lock() */ mutex_lock(&cpuset_mutex); - cpus_updated =3D !cpumask_equal(cs->effective_cpus, - oldcs->effective_cpus); - mems_updated =3D !nodes_equal(cs->effective_mems, oldcs->effective_mems); =20 /* * In the default hierarchy, enabling cpuset in the child cgroups @@ -3158,7 +3172,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) * in effective cpus and mems. 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charset="utf-8" There are two possible ways that migration of tasks from multiple source cpusets to a target cpuset can happen. Either a multithread application with threads in different cpusets is wholely moved to a new cpuset or disabling of v2 cpuset controller will move all the tasks in child cpusets to the parent cpuset. In the former case, t is the mm setting of the group leader that really matters. So cpuset_attach_old_cs should track the oldcs of the thread leader. In the latter case, effective_mems of child cpusets must always be a subset of the parent. So no real page migration will be necessary no matter which child cpuset is selected as cpuset_attach_old_cs. IOW, cpuset_attach_old_cs should be updated to match the latest task group leader in cpuset_can_attach(). Suggested-by: Ridong Chen Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 4457c4f11fce..b233a71f9b7c 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2967,6 +2967,20 @@ static int update_prstate(struct cpuset *cs, int new= _prs) /* * cpuset_can_attach() and cpuset_attach() specific internal data * Protected by cpuset_mutex + * + * The cpuset_attach_old_cs is used mainly by cpuset_migrate_mm() tp get t= he + * old_mems_allowed value. There are two ways that many-to-one cpuset migr= ation + * can happen: + * 1) A multithread application with threads in different cpusets is whole= ly + * moved to a new cpuset. + * 2) Disabling v2 cpuset controller will move all the tasks in child cpus= ets + * to the parent cpuset. + * + * In the former case, it is the mm setting of the group leader that really + * matters. So cpuset_attach_old_cs should track the oldcs of the thread + * leader. In the latter case, effective_mems of child cpusets must always + * be a subset of the parent. So no real page migration will be necessary = no + * matter which child cpuset is selected as cpuset_attach_old_cs. */ static struct cpuset *cpuset_attach_old_cs; static bool attach_cpus_updated; @@ -3069,6 +3083,10 @@ static int cpuset_can_attach(struct cgroup_taskset *= tset) if (ret) goto out_unlock; =20 + /* Update cpuset_attach_old_cs to the latest group leader */ + if (task =3D=3D task->group_leader) + cpuset_attach_old_cs =3D task_cs(task); + if (setsched_check) { ret =3D security_task_setscheduler(task); if (ret) --=20 2.54.0 From nobody Mon Jun 8 17:39:47 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14FE73EF0C2 for ; Wed, 27 May 2026 15:38:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896340; cv=none; b=JLFI+2XrwjM7xTBK79HCzuwmMhfpKzDrZam9hJoCZ8j/tWocOdStbQz5WkUgwh5bH0UX3coR/f6J3HfyA7I+wR4R8ct5VIi9cGaFNLvPCC5zXrW2BstkWJfGZTR5xUjL3RxS0SYBcqnX68pxisdXYrxDey6RqMgnAzH89sqtUxM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779896340; c=relaxed/simple; bh=dL4gdRYqnMCeb252iY/xIAcCW9yEioXpMDS7WqdE3UA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sTb04Yr7uYWXfvaYSpJ3NrnX2hApfcxDvIgKvthPhJzTrYQLUYhEXN5QFh4hkYUzpK3BmbKm54PU32l3uBWmY+rhTFiW5+ah41CqCGVdxbEYYOTqAVqlLHF5N/t2rolxdP5RIrdWaPra4NtEAwDclrSFK32XSeqWSvBHjWGviMQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ILTqPGpW; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ILTqPGpW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779896337; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Tt9Ea54oKwKAM2FGP6dVWKvNbQSOMPo66Nt3+qrZN94=; b=ILTqPGpWLDK8l+emU/IdT8qUUacqq9zyTW3K05ieMehEnB/3yuhEd78okEy5+iELc0yAyh /ohjA6/h7hxLFJQYIeghND+eO2SorTU4wH/fgsanuQ0qAoGJJH1T8/Su+eEFrARfoRe3MM 8d4ODWg5fCxULpW92Ng6lVRpzaRHndM= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-375-77ppD__vMWiNB1sSipYC3w-1; Wed, 27 May 2026 11:38:53 -0400 X-MC-Unique: 77ppD__vMWiNB1sSipYC3w-1 X-Mimecast-MFC-AGG-ID: 77ppD__vMWiNB1sSipYC3w_1779896332 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D3931195605F; Wed, 27 May 2026 15:38:51 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.81.53]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 098231800465; Wed, 27 May 2026 15:38:49 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Waiman Long Subject: [PATCH-next v3 4/5] cgroup/cpuset: Move mpol_rebind_mm/cpuset_migrate_mm() calls inside cpuset_attach_task() Date: Wed, 27 May 2026 11:37:59 -0400 Message-ID: <20260527153800.1557449-5-longman@redhat.com> In-Reply-To: <20260527153800.1557449-1-longman@redhat.com> References: <20260527153800.1557449-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" The cpuset_attach_task() was introduced in commit 42a11bf5c543 ("cgroup/cpuset: Make cpuset_fork() handle CLONE_INTO_CGROUP properly") to enable the CLONE_INTO_CGROUP flag of clone(2) to behave more like moving a task from one cpuset into another one. That commits didn't move the mpol_rebind_mm() and cpuset_migrate_mm() calls for group leader into cpuset_attach_task(). When the CLONE_INTO_CGROUP flag is used without CLONE_THREAD, the new task is its own group leader. So it is still not equivalent to moving task between cpusets in this case. Make CLONE_INTO_CGROUP behaves more close to cpuset_attach() by moving the mpol_rebind_mm() and cpuset_migrate_mm() calls inside cpuset_attach_task(). As a result, cpuset_attach_old_cs, attach_cpus_updated and attach_mems_updated will also need to be updated in cpuset_fork(). Besides, the original code use cpuset_attach_nodemask_to for both nodemask returned by guarantee_online_mems() used only by cpuset_change_task_nodemask() and cs->effective_mems in all other cases. Such dual use is now impractical by merging the two task iteration loops into one. So keep cpuset_attach_nodemask_to for the nodemask returned by guarantee_online_mems() and reference cs->effective_mems directly in all the other cases. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 90 ++++++++++++++++++++++-------------------- 1 file changed, 47 insertions(+), 43 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index b233a71f9b7c..7100575927f6 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3149,9 +3149,12 @@ static void cpuset_cancel_attach(struct cgroup_tasks= et *tset) */ static cpumask_var_t cpus_attach; static nodemask_t cpuset_attach_nodemask_to; +static bool queue_task_work; =20 static void cpuset_attach_task(struct cpuset *cs, struct task_struct *task) { + struct mm_struct *mm; + lockdep_assert_cpuset_lock_held(); =20 if (cs !=3D &top_cpuset) @@ -3165,24 +3168,56 @@ static void cpuset_attach_task(struct cpuset *cs, s= truct task_struct *task) */ WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach)); =20 + if (cpuset_v2() && !attach_mems_updated) + return; + cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to); cpuset1_update_task_spread_flags(cs, task); + + if (task !=3D task->group_leader) + return; + + /* + * Change mm for threadgroup leader. This is expensive and may + * sleep and should be moved outside migration path proper. + */ + mm =3D get_task_mm(task); + if (mm) { + struct cpuset *oldcs =3D cpuset_attach_old_cs; + + mpol_rebind_mm(mm, &cs->effective_mems); + + /* + * old_mems_allowed is the same with mems_allowed + * here, except if this task is being moved + * automatically due to hotplug. In that case + * @mems_allowed has been updated and is empty, so + * @old_mems_allowed is the right nodesets that we + * migrate mm from. + */ + if (is_memory_migrate(cs)) { + cpuset_migrate_mm(mm, &oldcs->old_mems_allowed, + &cs->effective_mems); + queue_task_work =3D true; + } else { + mmput(mm); + } + } } =20 static void cpuset_attach(struct cgroup_taskset *tset) { struct task_struct *task; - struct task_struct *leader; struct cgroup_subsys_state *css; struct cpuset *cs; struct cpuset *oldcs =3D cpuset_attach_old_cs; - bool queue_task_work =3D false; =20 cgroup_taskset_first(tset, &css); cs =3D css_cs(css); =20 lockdep_assert_cpus_held(); /* see cgroup_attach_lock() */ mutex_lock(&cpuset_mutex); + queue_task_work =3D false; =20 /* * In the default hierarchy, enabling cpuset in the child cgroups @@ -3190,53 +3225,18 @@ static void cpuset_attach(struct cgroup_taskset *ts= et) * in effective cpus and mems. In that case, we can optimize out * by skipping the task iteration and update. */ - if (cpuset_v2() && !attach_cpus_updated && !attach_mems_updated) { - cpuset_attach_nodemask_to =3D cs->effective_mems; + if (cpuset_v2() && !attach_cpus_updated && !attach_mems_updated) goto out; - } =20 guarantee_online_mems(cs, &cpuset_attach_nodemask_to); =20 cgroup_taskset_for_each(task, css, tset) cpuset_attach_task(cs, task); =20 - /* - * Change mm for all threadgroup leaders. This is expensive and may - * sleep and should be moved outside migration path proper. Skip it - * if there is no change in effective_mems and CS_MEMORY_MIGRATE is - * not set. - */ - cpuset_attach_nodemask_to =3D cs->effective_mems; - if (!is_memory_migrate(cs) && !attach_mems_updated) - goto out; - - cgroup_taskset_for_each_leader(leader, css, tset) { - struct mm_struct *mm =3D get_task_mm(leader); - - if (mm) { - mpol_rebind_mm(mm, &cpuset_attach_nodemask_to); - - /* - * old_mems_allowed is the same with mems_allowed - * here, except if this task is being moved - * automatically due to hotplug. In that case - * @mems_allowed has been updated and is empty, so - * @old_mems_allowed is the right nodesets that we - * migrate mm from. - */ - if (is_memory_migrate(cs)) { - cpuset_migrate_mm(mm, &oldcs->old_mems_allowed, - &cpuset_attach_nodemask_to); - queue_task_work =3D true; - } else - mmput(mm); - } - } - out: if (queue_task_work) schedule_flush_migrate_mm(); - cs->old_mems_allowed =3D cpuset_attach_nodemask_to; + cs->old_mems_allowed =3D cs->effective_mems; =20 if (cs->nr_migrate_dl_tasks) { cs->nr_deadline_tasks +=3D cs->nr_migrate_dl_tasks; @@ -3666,15 +3666,14 @@ static void cpuset_cancel_fork(struct task_struct *= task, struct css_set *cset) */ static void cpuset_fork(struct task_struct *task) { - struct cpuset *cs; - bool same_cs; + struct cpuset *cs, *oldcs; =20 rcu_read_lock(); cs =3D task_cs(task); - same_cs =3D (cs =3D=3D task_cs(current)); + oldcs =3D task_cs(current); rcu_read_unlock(); =20 - if (same_cs) { + if (cs =3D=3D oldcs) { if (cs =3D=3D &top_cpuset) return; 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Wed, 27 May 2026 15:38:53 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.22.81.53]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 15D181800465; Wed, 27 May 2026 15:38:51 +0000 (UTC) From: Waiman Long To: Chen Ridong , Tejun Heo , Johannes Weiner , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Ingo Molnar , Peter Zijlstra Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Aaron Tomlin , Waiman Long Subject: [PATCH-next v3 5/5] cgroup/cpuset: Support multiple source/destination cpusets for cpuset_*attach() Date: Wed, 27 May 2026 11:38:00 -0400 Message-ID: <20260527153800.1557449-6-longman@redhat.com> In-Reply-To: <20260527153800.1557449-1-longman@redhat.com> References: <20260527153800.1557449-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" With cgroup v2, the cgroup_taskset structure passed into the cgroup can_attach() and attach() methods can contain task migration data with multiple destination or source cpusets when the cpuset controller is enabled or disabled respectively. Since cpuset is threaded in both v1 and v2, another possible way to cause many-to-one migration is to move the whole process with multiple threads in different cpuset enabled threaded cgroups into another cpuset enabled cgroup. The current cpuset_can_attach() and cpuset_attach() functions still expect task migration is from one source cpuset to one destination cpuset. This has been the case since cpuset was enabled for cgroup v2 in commit 4ec22e9c5a90 ("cpuset: Enable cpuset controller in default hierarchy"). This problem is less an issue when enabling the cpuset controller as all the newly created child cpusets will have exactly the same set of CPUs and memory nodes except when deadline tasks are involved in migration as the deadline task accounting data can be off. It can be more problematic when the cpuset controller is disabled as their set of CPUs and memory nodes may differ from their parent or with the moving of multi-threaded process from different threaded cgroups. Fix that by tracking the set of source (old) and destination cpusets in singly linked lists and iterating them all to properly update the internal data. Also keep the current cs and oldcs variables up-to-date with the css and task iterators. To ensure proper DL tasks accounting, the nr_migrate_dl_tasks in both the source and destination cpusets are decremented/incremented with their values added to nr_deadline_tasks when the migration is successful. Fixes: 4ec22e9c5a90 ("cpuset: Enable cpuset controller in default hierarchy= ") Signed-off-by: Waiman Long --- kernel/cgroup/cpuset-internal.h | 6 + kernel/cgroup/cpuset.c | 206 +++++++++++++++++++++++--------- 2 files changed, 157 insertions(+), 55 deletions(-) diff --git a/kernel/cgroup/cpuset-internal.h b/kernel/cgroup/cpuset-interna= l.h index f7aaf01f7cd5..4c2772a7fd5e 100644 --- a/kernel/cgroup/cpuset-internal.h +++ b/kernel/cgroup/cpuset-internal.h @@ -161,6 +161,12 @@ struct cpuset { */ bool remote_partition; =20 + /* + * cpuset_can_attach() and cpuset_attach() specific data + */ + bool attach_node_in_llist; + struct llist_node attach_node; + /* * number of SCHED_DEADLINE tasks attached to this cpuset, so that we * know when to rebuild associated root domain bandwidth information. diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 7100575927f6..98ee001ef950 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -37,6 +37,7 @@ #include #include #include +#include =20 DEFINE_STATIC_KEY_FALSE(cpusets_pre_enable_key); DEFINE_STATIC_KEY_FALSE(cpusets_enabled_key); @@ -2983,6 +2984,8 @@ static int update_prstate(struct cpuset *cs, int new_= prs) * matter which child cpuset is selected as cpuset_attach_old_cs. */ static struct cpuset *cpuset_attach_old_cs; +static LLIST_HEAD(src_cs_head); +static LLIST_HEAD(dst_cs_head); static bool attach_cpus_updated; static bool attach_mems_updated; =20 @@ -2995,9 +2998,10 @@ static bool attach_mems_updated; * Also set the boolean flag passed in by @psetsched depending on if * security_task_setscheduler() call is needed and @oldcs is not NULL. */ -static int cpuset_can_attach_check(struct cpuset *cs, struct cpuset *oldcs, - bool *psetsched) +static int cpuset_can_attach_check(struct cpuset *cs, struct cpuset *oldcs= , bool *psetsched) { + bool cpu_match, mem_match; + if (cpumask_empty(cs->effective_cpus) || (!is_in_v2_mode() && nodes_empty(cs->mems_allowed))) return -ENOSPC; @@ -3008,15 +3012,34 @@ static int cpuset_can_attach_check(struct cpuset *c= s, struct cpuset *oldcs, /* * Update attach specific data */ - attach_cpus_updated =3D !cpumask_equal(cs->effective_cpus, oldcs->effecti= ve_cpus); - attach_mems_updated =3D !nodes_equal(cs->effective_mems, oldcs->effective= _mems); + if (!cs->attach_node_in_llist) { + llist_add(&cs->attach_node, &dst_cs_head); + cs->attach_node_in_llist =3D true; + } + if (!oldcs->attach_node_in_llist) { + llist_add(&oldcs->attach_node, &src_cs_head); + oldcs->attach_node_in_llist =3D true; + } + + cpu_match =3D cpumask_equal(cs->effective_cpus, oldcs->effective_cpus); + mem_match =3D nodes_equal(cs->effective_mems, oldcs->effective_mems); + + /* + * Set the updated flags whenever there is a mismatch in any of the + * src/dst pairs. + */ + if (!attach_cpus_updated) + attach_cpus_updated =3D !cpu_match; + + if (!attach_mems_updated) + attach_mems_updated =3D !mem_match; =20 /* * Skip rights over task setsched check in v2 when nothing changes, * migration permission derives from hierarchy ownership in * cgroup_procs_write_permission()). */ - *psetsched =3D !cpuset_v2() || attach_cpus_updated || attach_mems_updated; + *psetsched =3D !cpuset_v2() || !cpu_match || !mem_match; =20 /* * A v1 cpuset with tasks will have no CPU left only when CPU hotplug @@ -3031,33 +3054,103 @@ static int cpuset_can_attach_check(struct cpuset *= cs, struct cpuset *oldcs, return 0; } =20 -static int cpuset_reserve_dl_bw(struct cpuset *cs) +/* + * If reset_dl_bw is set, reset the previous dl_bw_alloc() call. Otherwise, + * update nr_deadline_tasks according to nr_migrate_dl_tasks in both source + * and destination cpusets. + */ +static void clear_attach_data(bool reset_dl_bw) +{ + struct cpuset *cs, *next; + + llist_for_each_entry_safe(cs, next, src_cs_head.first, attach_node) { + cs->attach_node.next =3D NULL; + cs->attach_node_in_llist =3D false; + if (cs->nr_migrate_dl_tasks && !reset_dl_bw) + cs->nr_deadline_tasks +=3D cs->nr_migrate_dl_tasks; + cs->nr_migrate_dl_tasks =3D 0; + } + + llist_for_each_entry_safe(cs, next, dst_cs_head.first, attach_node) { + cs->attach_node.next =3D NULL; + cs->attach_node_in_llist =3D false; + if (reset_dl_bw && cs->dl_bw_cpu >=3D 0) + dl_bw_free(cs->dl_bw_cpu, cs->sum_migrate_dl_bw); + if (cs->nr_migrate_dl_tasks && !reset_dl_bw) + cs->nr_deadline_tasks +=3D cs->nr_migrate_dl_tasks; + cs->nr_migrate_dl_tasks =3D 0; + cs->sum_migrate_dl_bw =3D 0; + cs->dl_bw_cpu =3D -1; + } + + src_cs_head.first =3D NULL; + dst_cs_head.first =3D NULL; + attach_cpus_updated =3D false; + attach_mems_updated =3D false; +} + +static int cpuset_reserve_dl_bw(void) { + struct cpuset *cs; int cpu, ret; =20 - if (!cs->sum_migrate_dl_bw) - return 0; + llist_for_each_entry(cs, dst_cs_head.first, attach_node) { + if (!cs->sum_migrate_dl_bw) + continue; =20 - cpu =3D cpumask_any_and(cpu_active_mask, cs->effective_cpus); - if (unlikely(cpu >=3D nr_cpu_ids)) - return -EINVAL; + cpu =3D cpumask_any_and(cpu_active_mask, cs->effective_cpus); + if (unlikely(cpu >=3D nr_cpu_ids)) + return -EINVAL; =20 - ret =3D dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); - if (ret) - return ret; + ret =3D dl_bw_alloc(cpu, cs->sum_migrate_dl_bw); + if (ret) + return ret; =20 - cs->dl_bw_cpu =3D cpu; + cs->dl_bw_cpu =3D cpu; + } return 0; } =20 -static void reset_migrate_dl_data(struct cpuset *cs) +static void set_attach_in_progress(void) { - cs->nr_migrate_dl_tasks =3D 0; - cs->sum_migrate_dl_bw =3D 0; - cs->dl_bw_cpu =3D -1; + struct cpuset *cs; + + /* + * Mark attach is in progress. This makes validate_change() fail + * changes which zero cpus/mems_allowed. + */ + llist_for_each_entry(cs, dst_cs_head.first, attach_node) + cs->attach_in_progress++; +} + +static void reset_attach_in_progress(void) +{ + struct cpuset *cs; + + llist_for_each_entry(cs, dst_cs_head.first, attach_node) + dec_attach_in_progress_locked(cs); } =20 -/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held= */ +/* + * Called by cgroups to determine if a cpuset is usable; cpuset_mutex held. + * + * With cgroup v2, enabling of cpuset controller in a cgroup subtree can + * cause @tset to contain task migration data from one parent cpuset to mu= ltiple + * child cpusets. Not much is needed to be done here other than tracking t= he + * number of DL tasks in each cpuset as the CPUs and memory nodes of the c= hild + * cpusets are exactly the same as the parent. + * + * Conversely, disabling of cpuset controller can cause @tset to contain t= ask + * migration data from multiple child cpusets to one parent cpuset. Here, = the + * CPUs and memory nodes of the child cpusets may be different from the pa= rent, + * but must be a subset of its parent. + * + * Another possible many-to-one migration is the moving of the whole + * multithreaded process with threads in different cpusets to another cpus= et. + * + * For all other use cases, @tset task migration data should be from one s= ource + * cpuset to one destination cpuset. + */ static int cpuset_can_attach(struct cgroup_taskset *tset) { struct cgroup_subsys_state *css; @@ -3079,6 +3172,16 @@ static int cpuset_can_attach(struct cgroup_taskset *= tset) goto out_unlock; =20 cgroup_taskset_for_each(task, css, tset) { + struct cpuset *newcs =3D css_cs(css); + struct cpuset *new_oldcs =3D task_cs(task); + + if ((newcs !=3D cs) || (new_oldcs !=3D oldcs)) { + cs =3D newcs; + oldcs =3D new_oldcs; + ret =3D cpuset_can_attach_check(cs, oldcs, &setsched_check); + if (ret) + goto out_unlock; + } ret =3D task_can_attach(task); if (ret) goto out_unlock; @@ -3100,23 +3203,19 @@ static int cpuset_can_attach(struct cgroup_taskset = *tset) * contribute to sum_migrate_dl_bw. */ cs->nr_migrate_dl_tasks++; + oldcs->nr_migrate_dl_tasks--; if (dl_task_needs_bw_move(task, cs->effective_cpus)) cs->sum_migrate_dl_bw +=3D task->dl.dl_bw; } } =20 - ret =3D cpuset_reserve_dl_bw(cs); + ret =3D cpuset_reserve_dl_bw(); =20 out_unlock: - if (ret) { - reset_migrate_dl_data(cs); - } else { - /* - * Mark attach is in progress. This makes validate_change() fail - * changes which zero cpus/mems_allowed. - */ - cs->attach_in_progress++; - } + if (ret) + clear_attach_data(true); + else + set_attach_in_progress(); =20 mutex_unlock(&cpuset_mutex); return ret; @@ -3131,14 +3230,8 @@ static void cpuset_cancel_attach(struct cgroup_tasks= et *tset) cs =3D css_cs(css); =20 mutex_lock(&cpuset_mutex); - dec_attach_in_progress_locked(cs); - - if (cs->dl_bw_cpu >=3D 0) - dl_bw_free(cs->dl_bw_cpu, cs->sum_migrate_dl_bw); - - if (cs->nr_migrate_dl_tasks) - reset_migrate_dl_data(cs); - + reset_attach_in_progress(); + clear_attach_data(true); mutex_unlock(&cpuset_mutex); } =20 @@ -3210,42 +3303,45 @@ static void cpuset_attach(struct cgroup_taskset *ts= et) struct task_struct *task; struct cgroup_subsys_state *css; struct cpuset *cs; - struct cpuset *oldcs =3D cpuset_attach_old_cs; =20 cgroup_taskset_first(tset, &css); cs =3D css_cs(css); - lockdep_assert_cpus_held(); /* see cgroup_attach_lock() */ mutex_lock(&cpuset_mutex); queue_task_work =3D false; =20 /* * In the default hierarchy, enabling cpuset in the child cgroups - * will trigger a number of cpuset_attach() calls with no change - * in effective cpus and mems. In that case, we can optimize out - * by skipping the task iteration and update. + * will trigger a cpuset_attach() call with no change in effective cpus + * and mems. In that case, we can optimize out by skipping the task + * iteration and update, but the destination cpuset list is iterated to + * set old_mems_sllowed. */ - if (cpuset_v2() && !attach_cpus_updated && !attach_mems_updated) + if (cpuset_v2() && !attach_cpus_updated && !attach_mems_updated) { + llist_for_each_entry(cs, dst_cs_head.first, attach_node) + cs->old_mems_allowed =3D cs->effective_mems; goto out; + } =20 guarantee_online_mems(cs, &cpuset_attach_nodemask_to); =20 - cgroup_taskset_for_each(task, css, tset) + cgroup_taskset_for_each(task, css, tset) { + struct cpuset *newcs =3D css_cs(css); + + if (newcs !=3D cs) { + cs->old_mems_allowed =3D cs->effective_mems; + cs =3D newcs; + guarantee_online_mems(cs, &cpuset_attach_nodemask_to); + } cpuset_attach_task(cs, task); + } =20 -out: if (queue_task_work) schedule_flush_migrate_mm(); cs->old_mems_allowed =3D cs->effective_mems; - - if (cs->nr_migrate_dl_tasks) { - cs->nr_deadline_tasks +=3D cs->nr_migrate_dl_tasks; - oldcs->nr_deadline_tasks -=3D cs->nr_migrate_dl_tasks; - reset_migrate_dl_data(cs); - } - - dec_attach_in_progress_locked(cs); - +out: + reset_attach_in_progress(); + clear_attach_data(false); mutex_unlock(&cpuset_mutex); } =20 --=20 2.54.0