On 7/15/2016 10:19 AM, Richard Weinberger wrote: > Hi! > > Am 15.07.2016 um 12:35 schrieb Topi Miettinen: >> Hello, >> >> There are many basic ways to control processes, including capabilities, >> cgroups and resource limits. However, there are far fewer ways to find out >> useful values for the limits, except blind trial and error. >> >> This patch series attempts to fix that by giving at least a nice starting >> point from the highwater mark values of the resources in question. >> I looked where each limit is checked and added a call to update the mark >> nearby. >> >> Example run of program from Documentation/accounting/getdelauys.c: >> >> ./getdelays -R -p `pidof smartd` >> printing resource accounting >> RLIMIT_CPU=0 >> RLIMIT_FSIZE=0 >> RLIMIT_DATA=18198528 >> RLIMIT_STACK=135168 >> RLIMIT_CORE=0 >> RLIMIT_RSS=0 >> RLIMIT_NPROC=1 >> RLIMIT_NOFILE=55 >> RLIMIT_MEMLOCK=0 >> RLIMIT_AS=130879488 >> RLIMIT_LOCKS=0 >> RLIMIT_SIGPENDING=0 >> RLIMIT_MSGQUEUE=0 >> RLIMIT_NICE=0 >> RLIMIT_RTPRIO=0 >> RLIMIT_RTTIME=0 >> >> ./getdelays -R -C /sys/fs/cgroup/systemd/system.slice/smartd.service/ >> printing resource accounting >> sleeping 1, blocked 0, running 0, stopped 0, uninterruptible 0 >> RLIMIT_CPU=0 >> RLIMIT_FSIZE=0 >> RLIMIT_DATA=18198528 >> RLIMIT_STACK=135168 >> RLIMIT_CORE=0 >> RLIMIT_RSS=0 >> RLIMIT_NPROC=1 >> RLIMIT_NOFILE=55 >> RLIMIT_MEMLOCK=0 >> RLIMIT_AS=130879488 >> RLIMIT_LOCKS=0 >> RLIMIT_SIGPENDING=0 >> RLIMIT_MSGQUEUE=0 >> RLIMIT_NICE=0 >> RLIMIT_RTPRIO=0 >> RLIMIT_RTTIME=0 >> >> In this example, smartd is running as a non-root user. The presented >> values can be used as a starting point for giving new limits to the >> service. > > I don't think it is worth sprinkling the kernel with > update_resource_highwatermark() > calls just to get these metrics. > > Can't we teach the existing perf infrastructure to collect these > highwatermarks for us?
I'm not sure about perf (I don't know the internals of perf well enough
to comment), but I'm sure the systemtap infrastructure could do this,
and a preconfigured systemtap script could be shipped with the package
that would allow this.
--
Doug Ledford <dledf...@redhat.com>
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