On Wed, May 05, 2021 at 12:59:40PM +0200, Peter Zijlstra wrote: > Hi, > > Due to: > > https://lkml.kernel.org/r/0000000000001d43ac05c0f5c6a0@xxxxxxxxxx > > and general principle, delayacct really shouldn't be using ktime (pvclock also > really shouldn't be doing what it does, but that's another story). This lead me > to looking at the SCHED_INFO, SCHEDSTATS, DELAYACCT (and PSI) accounting hell. > > The rest of the patches are an attempt at simplifying all that a little. All > that crud is enabled by default for distros which is leading to a death by a > thousand cuts. > > The last patch is an attempt at default disabling DELAYACCT, because I don't > think anybody actually uses that much, but what do I know, there were no ill > effects on my testbox. Perhaps we should mirror > /proc/sys/kernel/sched_schedstats and provide a delayacct sysctl for runtime > frobbing. > There are tools like iotop that use delayacct to display information. When the code was checked in, we did run SPEC* back in the day 2006 to find overheads, nothing significant showed. Do we have any date on the overhead your seeing? I'll look at the patches Balbir Singh.
