Re: What is "zio->i"?

Quoting George Mitchell <george+freebsd@m5p.com> (from Sun, 1 Jan 2023  
12:52:20 -0500):

> FreeBSD 13.1-RELEASE-p5, using SCHED_4BSD.
>
> What is "top" telling me when a process is in "zio->i" state?  Every
> so often, either firefox or thunderbird seemingly sits there
> contemplating its own navel in that state for up to a minute or two.
> It recovers of its own accord, of course, but I wish I knew what it
> meant.  Just a few months ago, I moved my /usr partition from UFS to
> ZFS, saving myself some fsck aggravation (rarely necessary, but very
> slow when needed).  "top" also reports some pretty big ARC numbers
> -- specifically, bigger than free memory, but not big enough to
> consume any swap space:
>
> Mem: 1232M Active, 1577M Inact, 27M Laundry, 2675M Wired, 175M Buf, 317M Free
> ARC: 1823M Total, 283M MFU, 1515M MRU, 16K Anon, 5117K Header, 13M Other
>      1712M Compressed, 2135M Uncompressed, 1.25:1 Ratio
> Swap: 8192M Total, 8192M Free

An incomplete list of wait channels is here:  
https://wiki.freebsd.org/WaitChannels

In your case it means most probably that it waits for some ZFS IO to finish.

Happy new year,
Alexander.

-- 
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