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authorHao Jia <jiahao.os@bytedance.com>2022-08-06 20:05:08 +0800
committerTejun Heo <tj@kernel.org>2022-08-15 12:35:13 -1000
commit2b97cf76289a4fcae66d7959b0d74a87207d7068 (patch)
tree43cbcf0d61b3ef4145c1a6d52365e85773a0bd11 /kernel/sched/psi.c
parent568035b01cfb107af8d2e4bd2fb9aea22cf5b868 (diff)
sched/psi: Zero the memory of struct psi_group
After commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default"), the memory used by struct psi_group is no longer allocated and zeroed in cgroup_create(). Since the memory of struct psi_group is not zeroed, the data in this memory is random, which will lead to inaccurate psi statistics when creating a new cgroup. So we use kzlloc() to allocate and zero the struct psi_group and remove the redundant zeroing in group_init(). Steps to reproduce: 1. Use cgroup v2 and enable CONFIG_PSI 2. Create a new cgroup, and query psi statistics mkdir /sys/fs/cgroup/test cat /sys/fs/cgroup/test/cpu.pressure some avg10=0.00 avg60=0.00 avg300=47927752200.00 total=12884901 full avg10=561815124.00 avg60=125835394188.00 avg300=1077090462000.00 total=10273561772 cat /sys/fs/cgroup/test/io.pressure some avg10=1040093132823.95 avg60=1203770351379.21 avg300=3862252669559.46 total=4294967296 full avg10=921884564601.39 avg60=0.00 avg300=1984507298.35 total=442381631 cat /sys/fs/cgroup/test/memory.pressure some avg10=232476085778.11 avg60=0.00 avg300=0.00 total=0 full avg10=0.00 avg60=0.00 avg300=2585658472280.57 total=12884901 Fixes: commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default") Signed-off-by: Hao Jia <jiahao.os@bytedance.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/sched/psi.c')
-rw-r--r--kernel/sched/psi.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index ec66b40bdd40..5ee615a59fe1 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -190,12 +190,8 @@ static void group_init(struct psi_group *group)
/* Init trigger-related members */
mutex_init(&group->trigger_lock);
INIT_LIST_HEAD(&group->triggers);
- memset(group->nr_triggers, 0, sizeof(group->nr_triggers));
- group->poll_states = 0;
group->poll_min_period = U32_MAX;
- memset(group->polling_total, 0, sizeof(group->polling_total));
group->polling_next_update = ULLONG_MAX;
- group->polling_until = 0;
init_waitqueue_head(&group->poll_wait);
timer_setup(&group->poll_timer, poll_timer_fn, 0);
rcu_assign_pointer(group->poll_task, NULL);
@@ -957,7 +953,7 @@ int psi_cgroup_alloc(struct cgroup *cgroup)
if (static_branch_likely(&psi_disabled))
return 0;
- cgroup->psi = kmalloc(sizeof(struct psi_group), GFP_KERNEL);
+ cgroup->psi = kzalloc(sizeof(struct psi_group), GFP_KERNEL);
if (!cgroup->psi)
return -ENOMEM;