519fabc7aa
Current 500ms min window size for psi triggers limits polling interval to 50ms to prevent polling threads from using too much cpu bandwidth by polling too frequently. However the number of cgroups with triggers is unlimited, so this protection can be defeated by creating multiple cgroups with psi triggers (triggers in each cgroup are served by a single "psimon" kernel thread). Instead of limiting min polling period, which also limits the latency of psi events, it's better to limit psi trigger creation to authorized users only, like we do for system-wide psi triggers (/proc/pressure/* files can be written only by processes with CAP_SYS_RESOURCE capability). This also makes access rules for cgroup psi files consistent with system-wide ones. Add a CAP_SYS_RESOURCE capability check for cgroup psi file writers and remove the psi window min size limitation. Suggested-by: Sudarshan Rajagopalan <quic_sudaraja@quicinc.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/all/cover.1676067791.git.quic_sudaraja@quicinc.com/ |
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| .. | ||
| Makefile | ||
| cgroup-internal.h | ||
| cgroup-v1.c | ||
| cgroup.c | ||
| cpuset.c | ||
| debug.c | ||
| freezer.c | ||
| legacy_freezer.c | ||
| misc.c | ||
| namespace.c | ||
| pids.c | ||
| rdma.c | ||
| rstat.c | ||