Messages in this thread | | | From | Domenico Cerasuolo <> | Subject | [PATCH v3 0/4] sched/psi: Allow unprivileged PSI polling | Date | Wed, 29 Mar 2023 09:48:38 +0200 |
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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.
The series is implemented in 4 steps in order to reduce the noise of the change.
V3: - restored renaming patch (#2 of 4) as suggested in review - rebased #3 and #4 on the renaming commit
V2: - removed renaming patch (previous 2/4) and applied suggested solution - changed update_triggers side effect removal as suggested in review - rebased core patch on other V2 changes
Domenico Cerasuolo (4): sched/psi: rearrange polling code in preparation sched/psi: rename existing poll members in preparation sched/psi: extract update_triggers side effect sched/psi: allow unprivileged polling of N*2s period
Documentation/accounting/psi.rst | 4 + include/linux/psi.h | 2 +- include/linux/psi_types.h | 43 +-- kernel/cgroup/cgroup.c | 2 +- kernel/sched/psi.c | 432 +++++++++++++++++-------------- 5 files changed, 262 insertions(+), 221 deletions(-)
-- 2.34.1
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