To: freebsd-hackers@freebsd.org Subject: Re: polling interval Message-ID: <Zw42Ur0H-bHMdsBX@vm2> In-Reply-To: <20241015174135.14866b319a49ddafeca6e3bb@dec.sakura.ne.jp> References: <Zw0Ez-zyTg9oodi8@int21h> <20241015000117.8a731ab66a1af876879f5ca8@dec.sakura.ne.jp> <Zw1WKr6uVYiHEPi0@int21h> <9513c9d9-8f7c-4842-a535-b387082e4e3e@sentex.net> <Zw2xTp3RH5fhlBib@int21h> <20241015174135.14866b319a49ddafeca6e3bb@dec.sakura.ne.jp>
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On Tue, Oct 15, 2024 at 05:41:35PM +0900, Tomoaki AOKI wrote:
>IIRC, in ancient days, default kern_hz (HZ) was 100 and bumped to 1000
>(current default) at some point. So trying around 10000 or 5000 and
>if not satisfactory, try increasing or decreasing would be nice for
>recent amd64 hardwares. (It depends, though.)
>
>FYI, I'm configuring kern.hz=4096 in /boot/loader.conf. Lost where I've
>seen, but recommended by somewhere.
The test vm here defaulted to 100. I got best throughput by turning it down to
8. Not by a lot though. I've commented out the hz value for now and rebooted:
% sysctl -a | ug hz
14: kern.clockrate: { hz = 100, tick = 10000, profhz = 8128, stathz = 127 }
191: kern.hz_min: 8
192: kern.hz_max: 137438
193: kern.hz: 100
6321: vfs.deferred_unmount.retry_delay_hz: 100
7299: debug.psm.hz: 20
8002: hw.atkbd.hz: 0
this is on -current built a few hrs earlier today
I'll try with hz as 0 or -1. I wish I could remember the linux article, as they
have a setting *something* like this and it's called something different.
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