Messages in this thread | | | Date | Mon, 28 Jan 2019 12:19:39 -0500 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 4.20 163/304] sched/topology: Add lowest CPU asymmetry sched_domain level pointer |
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On Mon, Jan 28, 2019 at 04:14:17PM +0000, Quentin Perret wrote: >Hi Sasha, > >On Monday 28 Jan 2019 at 10:41:20 (-0500), Sasha Levin wrote: >> From: Quentin Perret <quentin.perret@arm.com> >> >> [ Upstream commit 011b27bb5d3139e8b5fe9ceff1fc7f6dc3145071 ] >> >> Add another member to the family of per-cpu sched_domain shortcut >> pointers. This one, sd_asym_cpucapacity, points to the lowest level >> at which the SD_ASYM_CPUCAPACITY flag is set. While at it, rename the >> sd_asym shortcut to sd_asym_packing to avoid confusions. >> >> Generally speaking, the largest opportunity to save energy via >> scheduling comes from a smarter exploitation of heterogeneous platforms >> (i.e. big.LITTLE). Consequently, the sd_asym_cpucapacity shortcut will >> be used at first as the lowest domain where Energy-Aware Scheduling >> (EAS) should be applied. For example, it is possible to apply EAS within >> a socket on a multi-socket system, as long as each socket has an >> asymmetric topology. Energy-aware cross-sockets wake-up balancing will >> only happen when the system is over-utilized, or this_cpu and prev_cpu >> are in different sockets. > >Although I'm not really confident about the process for those AUTOSEL >patches, I think this one alone won't help anybody without the other ~10 >EAS patches. And I assume you definitely don't want to mark those as >stable, so I'm not sure if this one is a good candidate either.
I'll drop it then, thanks for the heads-up.
>On a side note, the best description I could find of AUTOSEL with a >5 min Google search is this: https://lwn.net/Articles/750057/ >Do you have any pointers to a doc where I can read up about AUTOSEL ?
For written material, this is based on Julia Lawall's work: https://soarsmu.github.io/papers/icse12-patch.pdf .
We did a talk last year which is more recent than the paper: https://www.youtube.com/watch?v=KWholDv6-Rw .
-- Thanks, Sasha
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