From: Waiman Long <longman@redhat.com>
To: Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-mm@kvack.org,
kernel-team@fb.com, pjt@google.com, luto@amacapital.net,
efault@gmx.de, longman@redhat.com
Subject: [RFC PATCH v2 14/17] cgroup: Enable printing of v2 controllers' cgroup hierarchy
Date: Mon, 15 May 2017 09:34:13 -0400 [thread overview]
Message-ID: <1494855256-12558-15-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1494855256-12558-1-git-send-email-longman@redhat.com>
This patch add a new debug control file on the cgroup v2 root directory
to print out the cgroup hierarchy for each of the v2 controllers.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/cgroup/debug.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 141 insertions(+)
diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c
index a2dbf77..3adb26a 100644
--- a/kernel/cgroup/debug.c
+++ b/kernel/cgroup/debug.c
@@ -268,6 +268,141 @@ static int cgroup_masks_read(struct seq_file *seq, void *v)
return 0;
}
+/*
+ * Print out all the child cgroup names that doesn't have a css for the
+ * corresponding cgroup_subsys. If a child cgroup has a css, put that into
+ * the given cglist to be processed in the next iteration.
+ */
+#define CGLIST_MAX 16
+static void print_hierarchy(struct seq_file *seq,
+ struct cgroup *cgrp,
+ struct cgroup_subsys *ss,
+ struct cgroup_subsys_state *css,
+ struct cgroup **cglist,
+ int *cgcnt)
+{
+ struct cgroup *child;
+ struct cgroup_subsys_state *child_css;
+ char cgname[64];
+
+ cgname[sizeof(cgname) - 1] = '\0';
+ /*
+ * Iterate all live children of the given cgroup.
+ */
+ list_for_each_entry(child, &cgrp->self.children, self.sibling) {
+ if (cgroup_is_dead(child))
+ continue;
+
+ child_css = rcu_dereference_check(child->subsys[ss->id], true);
+ if (child_css) {
+ WARN_ON(child_css->parent != css);
+ if (*cgcnt < CGLIST_MAX) {
+ cglist[*cgcnt] = child;
+ (*cgcnt)++;
+ }
+ continue;
+ }
+
+ /*
+ * Skip resource domain cgroup
+ */
+ if (test_bit(CGRP_RESOURCE_DOMAIN, &child->flags))
+ continue;
+
+ cgroup_name(child, cgname, sizeof(cgname)-1);
+ seq_putc(seq, ',');
+ seq_puts(seq, cgname);
+ print_hierarchy(seq, child, ss, css, cglist, cgcnt);
+ }
+}
+
+/*
+ * Print the hierachies with respect to each controller for the default
+ * hierarchy.
+ *
+ * Each child level is printed on a separate line. Set of cgroups that
+ * have the same css will be grouped together and separated by comma.
+ * Process in those cgroups will be in the same node (css) in the
+ * controller's hierarchy. There is an exception that for resource
+ * domain cgroup, the processes associated with its parent and its
+ * affiliates will be mapped to the css of that resource domain cgroup
+ * instead.
+ *
+ * If there are more than CGLIST_MAX sets of cgroups in each level,
+ * the extra ones will be skipped.
+ */
+static int controller_hierachies_read(struct seq_file *seq, void *v)
+{
+ struct cgroup *root = seq_css(seq)->cgroup;
+ struct cgroup_subsys *ss;
+ struct cgroup_subsys_state *css;
+ struct cgroup *cgrp;
+ struct cgroup *cglist[CGLIST_MAX];
+ struct cgroup *cg2list[CGLIST_MAX];
+ int i, idx, cgnum, cg2num;
+ char cgname[64];
+
+ cgname[sizeof(cgname) - 1] = '\0';
+ mutex_lock(&cgroup_mutex);
+ for_each_subsys(ss, i) {
+ if (!(root->root->subsys_mask & (1 << ss->id)))
+ continue;
+ seq_puts(seq, ss->name);
+ seq_puts(seq, ":\n");
+
+ cgnum = 1;
+ cg2num = 0;
+ cglist[0] = root;
+ idx = 0;
+ while (cgnum) {
+ if (idx)
+ seq_putc(seq, ' ');
+ cgrp = cglist[idx];
+ if (test_bit(CGRP_RESOURCE_DOMAIN, &cgrp->flags)) {
+ struct cgroup *parent;
+
+ parent = container_of(cgrp->self.parent,
+ struct cgroup, self);
+ cgroup_name(parent, cgname, sizeof(cgname)-1);
+ seq_printf(seq, "%s.rd", cgname);
+ } else {
+ cgroup_name(cgrp, cgname, sizeof(cgname)-1);
+ seq_puts(seq, cgname);
+ }
+ css = rcu_dereference_check(cgrp->subsys[ss->id], true);
+ WARN_ON(!css);
+
+ if (cgrp == root)
+ seq_printf(seq, "[%d]", css->id);
+ else
+ seq_printf(seq, "[%d:P=%d]", css->id,
+ css->parent->id);
+
+ /*
+ * List all the cgroups that use the current
+ * css.
+ */
+ print_hierarchy(seq, cgrp, ss, css, cg2list, &cg2num);
+
+ if (++idx < cgnum)
+ continue;
+
+ /*
+ * Move cg2list to cglist.
+ */
+ cgnum = cg2num;
+ idx = cg2num = 0;
+ if (cgnum)
+ memcpy(cglist, cg2list,
+ cgnum * sizeof(cglist[0]));
+ seq_putc(seq, '\n');
+ }
+ seq_putc(seq, '\n');
+ }
+ mutex_unlock(&cgroup_mutex);
+ return 0;
+}
+
static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
return (!cgroup_is_populated(css->cgroup) &&
@@ -314,6 +449,12 @@ static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
},
{
+ .name = "controller_hierachies",
+ .seq_show = controller_hierachies_read,
+ .flags = CFTYPE_ONLY_ON_ROOT|__CFTYPE_ONLY_ON_DFL,
+ },
+
+ {
.name = "releasable",
.read_u64 = releasable_read,
},
--
1.8.3.1
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next prev parent reply other threads:[~2017-05-15 13:35 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 13:33 [RFC PATCH v2 00/17] cgroup: Major changes to cgroup v2 core Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 01/17] cgroup: reorganize cgroup.procs / task write path Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 02/17] cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 03/17] cgroup: introduce cgroup->proc_cgrp and threaded css_set handling Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 04/17] cgroup: implement CSS_TASK_ITER_THREADED Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 05/17] cgroup: implement cgroup v2 thread support Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 06/17] cgroup: Fix reference counting bug in cgroup_procs_write() Waiman Long
2017-05-17 19:20 ` Tejun Heo
2017-05-15 13:34 ` [RFC PATCH v2 07/17] cgroup: Prevent kill_css() from being called more than once Waiman Long
2017-05-17 19:23 ` Tejun Heo
2017-05-17 20:24 ` Waiman Long
2017-05-17 21:34 ` Tejun Heo
2017-05-15 13:34 ` [RFC PATCH v2 08/17] cgroup: Move debug cgroup to its own file Waiman Long
2017-05-17 21:36 ` Tejun Heo
2017-05-18 15:29 ` Waiman Long
2017-05-18 15:52 ` Waiman Long
2017-05-19 19:21 ` Tejun Heo
2017-05-19 19:33 ` Waiman Long
2017-05-19 20:28 ` Tejun Heo
2017-05-15 13:34 ` [RFC PATCH v2 09/17] cgroup: Keep accurate count of tasks in each css_set Waiman Long
2017-05-17 21:40 ` Tejun Heo
2017-05-18 15:56 ` Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 10/17] cgroup: Make debug cgroup support v2 and thread mode Waiman Long
2017-05-17 21:43 ` Tejun Heo
2017-05-18 15:58 ` Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 11/17] cgroup: Implement new thread mode semantics Waiman Long
2017-05-17 21:47 ` Tejun Heo
2017-05-18 17:21 ` Waiman Long
2017-05-19 20:26 ` Tejun Heo
2017-05-19 20:58 ` Tejun Heo
2017-05-22 17:13 ` Waiman Long
2017-05-22 17:32 ` Waiman Long
2017-05-24 20:36 ` Tejun Heo
2017-05-24 21:17 ` Waiman Long
2017-05-24 21:27 ` Tejun Heo
2017-06-01 14:50 ` Tejun Heo
2017-06-01 15:10 ` Peter Zijlstra
2017-06-01 15:35 ` Tejun Heo
2017-06-01 18:44 ` Waiman Long
2017-06-01 18:47 ` Tejun Heo
2017-06-01 19:27 ` Waiman Long
2017-06-01 20:38 ` Tejun Heo
2017-06-01 20:48 ` Waiman Long
2017-06-01 20:52 ` Tejun Heo
2017-06-01 21:12 ` Waiman Long
2017-06-01 21:18 ` Tejun Heo
2017-06-02 20:36 ` Waiman Long
2017-06-03 10:33 ` Tejun Heo
2017-06-01 19:55 ` Waiman Long
2017-06-01 20:15 ` Waiman Long
2017-06-01 18:41 ` Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 12/17] cgroup: Remove cgroup v2 no internal process constraint Waiman Long
2017-05-19 20:38 ` Tejun Heo
2017-05-20 2:10 ` Mike Galbraith
2017-05-24 17:01 ` Tejun Heo
2017-05-22 16:56 ` Waiman Long
2017-05-24 17:05 ` Tejun Heo
2017-05-24 18:09 ` Waiman Long
2017-05-24 18:19 ` Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 13/17] cgroup: Allow fine-grained controllers control in cgroup v2 Waiman Long
2017-05-19 20:55 ` Tejun Heo
2017-05-19 21:20 ` Waiman Long
2017-05-24 17:31 ` Tejun Heo
2017-05-24 17:49 ` Waiman Long
2017-05-24 17:56 ` Tejun Heo
2017-05-24 18:17 ` Waiman Long
2017-05-15 13:34 ` Waiman Long [this message]
2017-05-15 13:34 ` [RFC PATCH v2 15/17] sched: Misc preps for cgroup unified hierarchy interface Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 16/17] sched: Implement interface for cgroup unified hierarchy Waiman Long
2017-05-15 13:34 ` [RFC PATCH v2 17/17] sched: Make cpu/cpuacct threaded controllers Waiman Long
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