Messages in this thread | | | Subject | Re: [RFC PATCH 0/9] Introduce housekeeping subsystem | From | Chris Metcalf <> | Date | Thu, 10 Aug 2017 09:57:37 -0400 |
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On 8/10/2017 8:54 AM, Frederic Weisbecker wrote: > But perhaps I should add a new NO_HZ_FULL_BUT_HOUSEKEEPING option. > Otherwise we'll change the meaning of NO_HZ_FULL_ALL way too much, to the point > that its default behaviour will be the exact opposite of the current one: by default > every CPU is housekeeping, so NO_HZ_FULL_ALL would have no effect anymore if we > don't set housekeeping boot option.
Maybe a CONFIG_HOUSEKEEPING_BOOT_ONLY as a way to restrict housekeeping by default to just the boot cpu. In conjunction with NOHZ_FULL_ALL you would then get the expected semantics.
> Also I plan to add a housekeeping option to offload the residual 1Hz tick from > nohz_full CPUs. So having "housekeeping=0,tick_offload" would make CPU 0 the > housekeeper, make the other CPUs nohz_full and handle their 1hz tick from CPU 0.
It does seem like that might be implied by requesting NOHZ_FULL on the core... or maybe it's just implied by TASK_ISOLATION. I've done a bad job of finding time to work on that since last year's Plumbers, but September looks good :)
-- Chris Metcalf, Mellanox Technologies http://www.mellanox.com
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