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.
