Messages in this thread | | | From | Suren Baghdasaryan <> | Date | Mon, 13 Mar 2023 08:29:37 -0700 | Subject | Re: [PATCH 0/4] sched/psi: Allow unprivileged PSI polling |
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On Thu, Mar 9, 2023 at 9:08 AM Domenico Cerasuolo <cerasuolodomenico@gmail.com> 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.
This sounds like an interesting usecase. I'll need to take a closer look once I'm back from vacation later this week. Thanks!
> > The series is implemented in 4 steps in order to reduce the noise of > the change. > > 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 | 412 ++++++++++++++++--------------- > 5 files changed, 250 insertions(+), 213 deletions(-) > > -- > 2.34.1 >
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