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Date: Fri, 25 Aug 2017 18:46:26 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: Warner Losh <imp@bsdimp.com>
Cc: Warner Losh <imp@freebsd.org>, src-committers <src-committers@freebsd.org>,
 "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>,
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Subject: Re: svn commit: r322863 - head/sys/cam
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On Fri, Aug 25, 2017 at 09:33:35AM -0600, Warner Losh wrote:

> On Fri, Aug 25, 2017 at 7:35 AM, Slawa Olhovchenkov <slw@zxy.spb.ru> wrote:
> 
> > On Thu, Aug 24, 2017 at 10:11:10PM +0000, Warner Losh wrote:
> >
> > > Author: imp
> > > Date: Thu Aug 24 22:11:10 2017
> > > New Revision: 322863
> > > URL: https://svnweb.freebsd.org/changeset/base/322863
> > >
> > > Log:
> > >   Expand the latency tracking array from 1.024s to 8.192s to help track
> > >   extreme outliers from dodgy drives. Adjust comments to reflect this,
> > >   and make sure that the number of latency buckets match in the two
> > >   places where it matters.
> >
> > May be up to 1min?
> >
> 
> I'm not sure what additional data you'll get between "totally sucks, at
> least 8s latency" and "totally sucks, at least 32s." or "totally sucks, at
> least 64s" though the latter isn't possible with the default timeouts...
> 
> I'm planning on adding a 'max' latency that's self-resetting instead of
> expanding the bucket upwards. I'm also contemplating expanding it down to
> 100us or even 10us since nda serves nvme drives which easily can be sub
> 100us.

This is just stat data?
Don't produce error messages about timeout commands and etc?