diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2019-05-14 15:41:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-14 19:52:48 -0700 |
| commit | 0e94682b73bfa6c44c98af7a26771c9c08c055d5 (patch) | |
| tree | c9bb857be3cef50fc3dbdc319c514dd4d7e93238 /include/linux/psi.h | |
| parent | 8af0c18af1425fc70686c0fdcfc0072cd8431aa0 (diff) | |
psi: introduce psi monitor
Psi monitor aims to provide a low-latency short-term pressure detection
mechanism configurable by users. It allows users to monitor psi metrics
growth and trigger events whenever a metric raises above user-defined
threshold within user-defined time window.
Time window and threshold are both expressed in usecs. Multiple psi
resources with different thresholds and window sizes can be monitored
concurrently.
Psi monitors activate when system enters stall state for the monitored
psi metric and deactivate upon exit from the stall state. While system
is in the stall state psi signal growth is monitored at a rate of 10
times per tracking window. Min window size is 500ms, therefore the min
monitoring interval is 50ms. Max window size is 10s with monitoring
interval of 1s.
When activated psi monitor stays active for at least the duration of one
tracking window to avoid repeated activations/deactivations when psi
signal is bouncing.
Notifications to the users are rate-limited to one per tracking window.
Link: http://lkml.kernel.org/r/20190319235619.260832-8-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/psi.h')
| -rw-r--r-- | include/linux/psi.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/psi.h b/include/linux/psi.h index 7006008d5b72..af892c290116 100644 --- a/include/linux/psi.h +++ b/include/linux/psi.h @@ -4,6 +4,7 @@ #include <linux/jump_label.h> #include <linux/psi_types.h> #include <linux/sched.h> +#include <linux/poll.h> struct seq_file; struct css_set; @@ -26,6 +27,13 @@ int psi_show(struct seq_file *s, struct psi_group *group, enum psi_res res); int psi_cgroup_alloc(struct cgroup *cgrp); void psi_cgroup_free(struct cgroup *cgrp); void cgroup_move_task(struct task_struct *p, struct css_set *to); + +struct psi_trigger *psi_trigger_create(struct psi_group *group, + char *buf, size_t nbytes, enum psi_res res); +void psi_trigger_replace(void **trigger_ptr, struct psi_trigger *t); + +__poll_t psi_trigger_poll(void **trigger_ptr, struct file *file, + poll_table *wait); #endif #else /* CONFIG_PSI */ |