Messages in this thread | | | From | Linus Walleij <> | Date | Thu, 6 Oct 2016 10:04:41 +0200 | Subject | Re: [PATCH V3 00/11] block-throttle: add .high limit |
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On Tue, Oct 4, 2016 at 9:14 PM, Tejun Heo <tj@kernel.org> wrote:
> I get that bfq can be a good compromise on most desktop workloads and > behave reasonably well for some server workloads with the slice > expiration mechanism but it really isn't an IO resource partitioning > mechanism.
Not just desktops, also Android phones.
So why not have BFQ as a separate scheduling policy upstream, alongside CFQ, deadline and noop?
I understand the CPU scheduler people's position that they want one scheduler for everyone's everyday loads (except RT and SCHED_DEADLINE) and I guess that is the source of the highlander "there can be only one" argument, but note this:
kernel/Kconfig.preempt:
config PREEMPT_NONE bool "No Forced Preemption (Server)" config PREEMPT_VOLUNTARY bool "Voluntary Kernel Preemption (Desktop)" config PREEMPT bool "Preemptible Kernel (Low-Latency Desktop)"
We're already doing the per-usecase Kconfig thing for preemption. But maybe somebody already hates that and want to get rid of it, I don't know.
Yours, Linus Walleij
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