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.
V7:
- fix code style in psi trigger create/destroy aggregators paths
V6:
- fix trigger creation logic now using proper locks
V5:
- few suggested code style changes in psi.c and psy_types.h
- fix trigger destruction logic now using proper locks
V4:
- fixed psi_open leftover usage in IRQ accounting (patch 4/4)
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 | 443 +++++++++++++++++--------------
5 files changed, 276 insertions(+), 218 deletions(-)
--
2.34.1
On Thu, Mar 30, 2023 at 1:06 PM Domenico Cerasuolo
<[email protected]> wrote:
>
> 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.
Thanks! For the entire series
Acked-by: Suren Baghdasaryan <[email protected]>
>
> V7:
> - fix code style in psi trigger create/destroy aggregators paths
>
> V6:
> - fix trigger creation logic now using proper locks
>
> V5:
> - few suggested code style changes in psi.c and psy_types.h
> - fix trigger destruction logic now using proper locks
>
> V4:
> - fixed psi_open leftover usage in IRQ accounting (patch 4/4)
>
> 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 | 443 +++++++++++++++++--------------
> 5 files changed, 276 insertions(+), 218 deletions(-)
>
> --
> 2.34.1
>