RE: [opensuse-kernel] [PATCH V2] config: arm64 switch from PREEMPT_NONE to PREEMPT

-----Original Message----- From: Takashi Iwai Sent: 10 January 2019 11:03 To: Guillaume GARDET Cc: opensuse-kernel@opensuse.org; Andreas Färber ; Alexander Graf Subject: Re: [opensuse-kernel] [PATCH V2] config: arm64 switch from PREEMPT_NONE to PREEMPT

On Thu, 10 Jan 2019 10:50:59 +0100, Guillaume GARDET wrote:

...

as we need to have low latency on some systems.

Actually, it's an open question whether we still want to keep CONFIG_PREEMPT or not on other archs, too. CONFIG_PREEMPT hits performance significantly.

I don't know much about other distros, but IIRC, Fedora is using CONFIG_PREEMPT_VOLUNTARY instead. Ubuntu provide both non- preempt and CONFIG_PREEMPT versions? Correct me if wrong.

True for Fedora. Ubuntu has two flavors: CONFIG_PREEMPT_VOLUNTARY and CONFIG_PREEMPT. Default x86_64 is CONFIG_PREEMPT_VOLUNTARY. So, the question is more switching to CONFIG_PREEMPT or CONFIG_PREEMPT_VOLUNTARY, right?

...

It also aligns to default arm64 kernel config.

That's more convincing reason in this case, though :)

When in doubt , it is probably a good idea to follow defconfig. @Andreas, any opinion for aarch64 preemption model? Thanks, Guillaume

thanks,

Takashi -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org

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