Date: Fri, 17 Feb 2017 15:52:06 +0000 From: Edward Tomasz =?utf-8?Q?Napiera=C5=82a?= <trasz@FreeBSD.org> To: Alexander Motin <mav@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r313854 - head/sys/cam/ctl Message-ID: <20170217155206.GA40422@brick> In-Reply-To: <653994e0-b49f-21ac-3bdc-d6fc34496b29@FreeBSD.org> References: <201702170522.v1H5MwGK027647@repo.freebsd.org> <20170217102408.GA74901@brick> <653994e0-b49f-21ac-3bdc-d6fc34496b29@FreeBSD.org>
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On 0217T1522, Alexander Motin wrote: > On 17.02.2017 12:24, Edward Tomasz Napierała wrote: > > On 0217T0522, Alexander Motin wrote: > >> Author: mav > >> Date: Fri Feb 17 05:22:58 2017 > >> New Revision: 313854 > >> URL: https://svnweb.freebsd.org/changeset/base/313854 > >> > >> Log: > >> Change the way MaxCmdSN is used. > >> > >> Before this change MaxCmdSN was reported as CmdSN + delta, that made it > >> limit number of requests in transmission from the initiator to target, > >> that was pretty useless. After this change MaxCmdSN limits number of > >> requests queued to CTL, i.e. maximal queue depth for the initiator. > >> The default limit is 256 outstanding requests per initiator at a time. > >> > >> This code uses existing cs_outstanding_ctl_pdus counter to track queue > >> depth. It's semantics doen't perfectly match, but close enough to not > >> add another counter. Just don't set the maxtags below 2. > > > > I like the change in principle, but I don't like the gratuitous change > > of sysctl name. It will break people's configs. Could you rename it > > back? Thanks! > > But its meaning is different now. Do you know anybody tuning the old > sysctl? I can't imagine who would do it and what for. Yes. It's been asked about a few times on forums, and it's documented in ctl(4). The new meaning is slightly different, sure, but I'd say it's very close, except that now it really works :-)
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