Date: Wed, 22 Mar 2023 19:31:57 +0100 From: Matthias Andree <mandree@FreeBSD.org> To: freebsd-hackers@freebsd.org Subject: Re: Periodic rant about SCHED_ULE Message-ID: <c3f5f667-ba0b-c40c-b8a6-19d1c9c63c5f@FreeBSD.org> In-Reply-To: <8cfdb951-9b1f-ecd3-2291-7a528e1b042c@m5p.com> References: <a401e51a-250a-64a0-15cb-ff79bcefbf94@m5p.com> <8173cc7e-e934-dd5c-312a-1dfa886941aa@FreeBSD.org> <8cfdb951-9b1f-ecd3-2291-7a528e1b042c@m5p.com>
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Am 22.03.23 um 15:41 schrieb George Mitchell: > On 3/22/23 06:17, Matthias Andree wrote: >> Am 21.03.23 um 23:52 schrieb George Mitchell: >>> Yes, you've all heard it before [... blah blah blah ...] >> >> Can you please also give figures how much CPU time has been allotted >> to dnetc in that respective situations? >> > I let the scheduler do the time allocation. The result is that dnetc > gobbles whatever time remains available when higher priority processes > (i.e. every other process on the system) have nothing to do. With > SCHED_4BSD the resulting idle time is 0 (as reported by top). I did > not take note of the idle time when I was doing the SCHED_ULE run. You are not answering my question. I asked how much time did dnetc use in the time where you were doing your test compile. The next question is then where you get the idea that a scheduler must interpret 20 as "only if idle". Linux has scheduling classes with "idle" and "best-effort" priority classes, for one. Yes, there are reports that FreeBSD is not responsive by default - but this may make it get overall better throughput at the expense of responsiveness, because it might be doing fewer context switches. So just complaining about a longer buildworld without seeing how much dnetc did in the same wallclock time period is useless. Periodic rant's don't fix this lack of information. -- Matthias Andree FreeBSD ports committer
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