From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 03/10] cgroup: introduce CGRP_MIGRATE_* flags Date: Fri, 11 Mar 2016 10:41:21 -0500 Message-ID: <1457710888-31182-4-git-send-email-tj@kernel.org> References: <1457710888-31182-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=fGqKsWwc7iYvqxKieokcwDodtHf5StBI39VMckJQzVU=; b=J/+WjfsSsp6sEGbiNqfY9L6Y/TkVZXzWYahOkXsRlMs7tQyJC8Ty6Fe/Sd+ov5yd3r NSRr/z71v4TCCElboEaaAOgUm8WUTDdWXBx5gHdiWXJw9GBS7UClg8Ai6ZMGmkI8ZaKE 0m85iBdktHwlHGZ+O+HVU18q8N8irlIEcVYzsEvVN7cSGSGOclsgZWDjuGf/fHq3zfEE QYHx4o++07Vsx5QwI1Nlq3cZmbd/pFqXL5/3e0H9499sXnN1iO4qk9qbCJkjPuz120Dv MXo3G/sTpM0yuoZZspJ/IX6CWQBnpT+hSZd2ZxTQ5xx/JKLzIHFLbQaz7co16Io8GeXG umDQ== In-Reply-To: <1457710888-31182-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org, mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, pjt-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org, Tejun Heo Currently, the only migration modifier is boolean @threadgroup. Make the functions pass around unsigned flag mask instead and replace @threadgroup with CGRP_MIGRATE_PROCESS. This will allow addition of other modifiers. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo --- kernel/cgroup.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 4c3c43e..8ecb8d6 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2403,6 +2403,10 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset, return NULL; } +enum { + CGRP_MIGRATE_PROCESS = (1 << 0), /* migrate the whole process */ +}; + /** * cgroup_taskset_migrate - migrate a taskset * @tset: taget taskset @@ -2634,7 +2638,7 @@ static int cgroup_migrate_prepare_dst(struct list_head *preloaded_csets) /** * cgroup_migrate - migrate a process or task to a cgroup * @leader: the leader of the process or the task to migrate - * @threadgroup: whether @leader points to the whole process or a single task + * @mflags: CGRP_MIGRATE_* flags * @root: cgroup root migration is taking place on * * Migrate a process or task denoted by @leader. If migrating a process, @@ -2649,7 +2653,7 @@ static int cgroup_migrate_prepare_dst(struct list_head *preloaded_csets) * decided for all targets by invoking group_migrate_prepare_dst() before * actually starting migrating. */ -static int cgroup_migrate(struct task_struct *leader, bool threadgroup, +static int cgroup_migrate(struct task_struct *leader, unsigned mflags, struct cgroup_root *root) { struct cgroup_taskset tset = CGROUP_TASKSET_INIT(tset); @@ -2665,7 +2669,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup, task = leader; do { cgroup_taskset_add(task, &tset); - if (!threadgroup) + if (!(mflags & CGRP_MIGRATE_PROCESS)) break; } while_each_thread(leader, task); rcu_read_unlock(); @@ -2678,12 +2682,12 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup, * cgroup_attach_task - attach a task or a whole threadgroup to a cgroup * @dst_cgrp: the cgroup to attach to * @leader: the task or the leader of the threadgroup to be attached - * @threadgroup: attach the whole threadgroup? + * @mflags: CGRP_MIGRATE_* flags * * Call holding cgroup_mutex and cgroup_threadgroup_rwsem. */ static int cgroup_attach_task(struct cgroup *dst_cgrp, - struct task_struct *leader, bool threadgroup) + struct task_struct *leader, unsigned mflags) { LIST_HEAD(preloaded_csets); struct task_struct *task; @@ -2699,7 +2703,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, do { cgroup_migrate_add_src(task_css_set(task), dst_cgrp, &preloaded_csets); - if (!threadgroup) + if (!(mflags & CGRP_MIGRATE_PROCESS)) break; } while_each_thread(leader, task); rcu_read_unlock(); @@ -2708,7 +2712,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, /* prepare dst csets and commit */ ret = cgroup_migrate_prepare_dst(&preloaded_csets); if (!ret) - ret = cgroup_migrate(leader, threadgroup, dst_cgrp->root); + ret = cgroup_migrate(leader, mflags, dst_cgrp->root); cgroup_migrate_finish(&preloaded_csets); return ret; @@ -2761,7 +2765,7 @@ static int cgroup_procs_write_permission(struct task_struct *task, * cgroup_mutex and threadgroup. */ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf, - size_t nbytes, loff_t off, bool threadgroup) + size_t nbytes, loff_t off, unsigned mflags) { struct task_struct *tsk; struct cgroup *cgrp; @@ -2787,7 +2791,7 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf, tsk = current; } - if (threadgroup) + if (mflags & CGRP_MIGRATE_PROCESS) tsk = tsk->group_leader; /* @@ -2805,7 +2809,7 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf, ret = cgroup_procs_write_permission(tsk, cgrp, of); if (!ret) - ret = cgroup_attach_task(cgrp, tsk, threadgroup); + ret = cgroup_attach_task(cgrp, tsk, mflags); put_task_struct(tsk); goto out_unlock_threadgroup; @@ -2840,7 +2844,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) from_cgrp = task_cgroup_from_root(from, root); spin_unlock_bh(&css_set_lock); - retval = cgroup_attach_task(from_cgrp, tsk, false); + retval = cgroup_attach_task(from_cgrp, tsk, 0); if (retval) break; } @@ -2853,13 +2857,13 @@ EXPORT_SYMBOL_GPL(cgroup_attach_task_all); static ssize_t cgroup_tasks_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { - return __cgroup_procs_write(of, buf, nbytes, off, false); + return __cgroup_procs_write(of, buf, nbytes, off, 0); } static ssize_t cgroup_procs_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { - return __cgroup_procs_write(of, buf, nbytes, off, true); + return __cgroup_procs_write(of, buf, nbytes, off, CGRP_MIGRATE_PROCESS); } static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of, @@ -4233,7 +4237,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) css_task_iter_end(&it); if (task) { - ret = cgroup_migrate(task, false, to->root); + ret = cgroup_migrate(task, 0, to->root); put_task_struct(task); } } while (task && !ret); -- 2.5.0