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author | Waiman Long <longman@redhat.com> | 2017-07-21 17:14:51 +0200 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2017-07-21 17:14:51 +0200 |
commit | 7a0cf0e74ab6cfd8e561f5f12860d4ff8844905a (patch) | |
tree | a4fb0b9648bc07969beffbe350005fecd4ade14f /kernel | |
parent | cgroup: implement cgroup v2 thread support (diff) | |
download | linux-7a0cf0e74ab6cfd8e561f5f12860d4ff8844905a.tar.xz linux-7a0cf0e74ab6cfd8e561f5f12860d4ff8844905a.zip |
cgroup: update debug controller to print out thread mode information
Update debug controller so that it prints out debug info about thread
mode.
1) The relationship between proc_cset and threaded_csets are displayed.
2) The status of being a thread root or threaded cgroup is displayed.
This patch is extracted from Waiman's larger patch.
v2: - Removed [thread root] / [threaded] from debug.cgroup_css_links
file as the same information is available from cgroup.type.
Suggested by Waiman.
- Threaded marking is moved to the previous patch.
Patch-originally-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cgroup/cgroup-internal.h | 2 | ||||
-rw-r--r-- | kernel/cgroup/cgroup.c | 4 | ||||
-rw-r--r-- | kernel/cgroup/debug.c | 52 |
3 files changed, 42 insertions, 16 deletions
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index f10eb19ddf04..c167a40278e6 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -153,6 +153,8 @@ static inline void get_css_set(struct css_set *cset) bool cgroup_ssid_enabled(int ssid); bool cgroup_on_dfl(const struct cgroup *cgrp); +bool cgroup_is_thread_root(struct cgroup *cgrp); +bool cgroup_is_threaded(struct cgroup *cgrp); struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root); struct cgroup *task_cgroup_from_root(struct task_struct *task, diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index c396e701c206..e9a377dc5bdb 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -333,7 +333,7 @@ static bool cgroup_has_tasks(struct cgroup *cgrp) return cgrp->nr_populated_csets; } -static bool cgroup_is_threaded(struct cgroup *cgrp) +bool cgroup_is_threaded(struct cgroup *cgrp) { return cgrp->dom_cgrp != cgrp; } @@ -372,7 +372,7 @@ static bool cgroup_can_be_thread_root(struct cgroup *cgrp) } /* is @cgrp root of a threaded subtree? */ -static bool cgroup_is_thread_root(struct cgroup *cgrp) +bool cgroup_is_thread_root(struct cgroup *cgrp) { /* thread root should be a domain */ if (cgroup_is_threaded(cgrp)) diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c index 787a242fa69d..f661b4cc5efd 100644 --- a/kernel/cgroup/debug.c +++ b/kernel/cgroup/debug.c @@ -114,27 +114,49 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v) { struct cgroup_subsys_state *css = seq_css(seq); struct cgrp_cset_link *link; - int dead_cnt = 0, extra_refs = 0; + int dead_cnt = 0, extra_refs = 0, threaded_csets = 0; spin_lock_irq(&css_set_lock); + list_for_each_entry(link, &css->cgroup->cset_links, cset_link) { struct css_set *cset = link->cset; struct task_struct *task; int count = 0; int refcnt = refcount_read(&cset->refcount); - seq_printf(seq, " %d", refcnt); - if (refcnt - cset->nr_tasks > 0) { - int extra = refcnt - cset->nr_tasks; - - seq_printf(seq, " +%d", extra); - /* - * Take out the one additional reference in - * init_css_set. - */ - if (cset == &init_css_set) - extra--; - extra_refs += extra; + /* + * Print out the proc_cset and threaded_cset relationship + * and highlight difference between refcount and task_count. + */ + seq_printf(seq, "css_set %pK", cset); + if (rcu_dereference_protected(cset->dom_cset, 1) != cset) { + threaded_csets++; + seq_printf(seq, "=>%pK", cset->dom_cset); + } + if (!list_empty(&cset->threaded_csets)) { + struct css_set *tcset; + int idx = 0; + + list_for_each_entry(tcset, &cset->threaded_csets, + threaded_csets_node) { + seq_puts(seq, idx ? "," : "<="); + seq_printf(seq, "%pK", tcset); + idx++; + } + } else { + seq_printf(seq, " %d", refcnt); + if (refcnt - cset->nr_tasks > 0) { + int extra = refcnt - cset->nr_tasks; + + seq_printf(seq, " +%d", extra); + /* + * Take out the one additional reference in + * init_css_set. + */ + if (cset == &init_css_set) + extra--; + extra_refs += extra; + } } seq_puts(seq, "\n"); @@ -163,10 +185,12 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v) } spin_unlock_irq(&css_set_lock); - if (!dead_cnt && !extra_refs) + if (!dead_cnt && !extra_refs && !threaded_csets) return 0; seq_puts(seq, "\n"); + if (threaded_csets) + seq_printf(seq, "threaded css_sets = %d\n", threaded_csets); if (extra_refs) seq_printf(seq, "extra references = %d\n", extra_refs); if (dead_cnt) |