Domenico Cerasuolo d5dca19776 sched/psi: Allow unprivileged polling of N*2s period ... [ Upstream commit d82caa2735 ] PSI offers 2 mechanisms to get information about a specific resource pressure. One is reading from /proc/pressure/<resource>, which gives average pressures aggregated every 2s. The other is creating a pollable fd for a specific resource and cgroup. The trigger creation requires CAP_SYS_RESOURCE, and gives the possibility to pick specific time window and threshold, spawing an RT thread to aggregate the data. Systemd would like to provide containers the option to monitor pressure on their own cgroup and sub-cgroups. For example, if systemd launches a container that itself then launches services, the container should have the ability to poll() for pressure in individual services. But neither the container nor the services are privileged. This patch implements a mechanism to allow unprivileged users to create pressure triggers. The difference with privileged triggers creation is that unprivileged ones must have a time window that's a multiple of 2s. This is so that we can avoid unrestricted spawning of rt threads, and use instead the same aggregation mechanism done for the averages, which runs independently of any triggers. Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lore.kernel.org/r/20230330105418.77061-5-cerasuolodomenico@gmail.com Stable-dep-of: aff037078e ("sched/psi: use kernfs polling functions for PSI trigger polling") Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-07-27 08:50:38 +02:00
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Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
cgroup-internal.h	memcg: Fix possible use-after-free in memcg_write_event_control()	2022-12-08 10:40:58 -08:00
cgroup-v1.c	cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks()	2023-06-21 16:00:51 +02:00
cgroup.c	sched/psi: Allow unprivileged polling of N*2s period	2023-07-27 08:50:38 +02:00
cpuset.c	cgroup/cpuset: Add cpuset_can_fork() and cpuset_cancel_fork() methods	2023-04-20 12:35:14 +02:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: cleanup comments	2022-03-13 19:19:27 -10:00
legacy_freezer.c	cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex in freezer_css_{online,offline}()	2023-06-28 11:12:25 +02:00
misc.c	misc_cgroup: remove error log to avoid log flood	2021-09-20 07:35:38 -10:00
namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
pids.c	cgroup: add pids.peak interface for pids controller	2022-09-04 09:26:51 -10:00
rdma.c	cgroup: fix spelling mistakes	2021-05-24 12:45:26 -04:00
rstat.c	cgroup: fix display of forceidle time at root	2023-04-20 12:35:13 +02:00