Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 3 Nov 2014 13:18:51 +0200
From:      Konstantin Belousov <kostikbel@gmail.com>
To:        Attilio Rao <attilio@freebsd.org>
Cc:        "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>
Subject:   Re: svn commit: r273966 - in head: share/man/man9 sys/kern sys/sys
Message-ID:  <20141103111851.GM53947@kib.kiev.ua>
In-Reply-To: <CAJ-FndBY55kfCeqDTmas7qOEKsAxQ9mFYGy767oDb%2B0LPgzX_Q@mail.gmail.com>
References:  <20141102165916.GY53947@kib.kiev.ua> <CAJ-FndAbhBFQ1gD64Wi210zH-0kfxjkkUJRNYHnFnmW%2BKAhm2w@mail.gmail.com> <20141102174958.GZ53947@kib.kiev.ua> <CAJ-FndC_3Te6Y7N0%2B8ZddH8i72cxH%2BACHm=EShHp=QDoX4xSow@mail.gmail.com> <20141102191029.GA53947@kib.kiev.ua> <CAJ-FndBz25uka6Zz%2Bx_bRykJCUQLCPxJoPHidc5FuTtZ=Kfb9w@mail.gmail.com> <20141102213819.GF53947@kib.kiev.ua> <CAJ-FndASC832PTqaVfYqPvFxOdvroxbyT4LaJ8Job6xhiXcE=w@mail.gmail.com> <20141102224934.GG53947@kib.kiev.ua> <CAJ-FndBY55kfCeqDTmas7qOEKsAxQ9mFYGy767oDb%2B0LPgzX_Q@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Nov 03, 2014 at 11:34:48AM +0100, Attilio Rao wrote:
> On Sun, Nov 2, 2014 at 11:49 PM, Konstantin Belousov
> <kostikbel@gmail.com> wrote:
> > On Sun, Nov 02, 2014 at 11:37:57PM +0100, Attilio Rao wrote:
> >> On Sun, Nov 2, 2014 at 10:38 PM, Konstantin Belousov
> >> <kostikbel@gmail.com> wrote:
> >> > On Sun, Nov 02, 2014 at 10:17:26PM +0100, Attilio Rao wrote:
> >> >> I think that your initial patch (what is in head now) is a better approach.
> >> >> I would just make it a lockinit() flag to make it less alien to the KPI.
> >> >>
> >> >
> >> > Ok.
> >> >
> >> > Can you explain what would the proposed lockinit() flag do ? What should
> >> > it change comparing with the current code ?
> >>
> >> You now provide LK_NODDLKTREAT on a call basis.
> >> The lockinit() flag would embed this into the lock attribute and make
> >> it always real, without the need for the callers to provide
> >> LK_NODDLKTREAT on a call basis.
> >
> > Am I reading your proposal right ? Do you mean, that for all vnodes,
> > I should disable exclusive starvation avoidance at all ? I completely
> > disagree with this.
> 
> No, I'm saying that we should support doing this at the KPI level. Not
> that you should enable this for all the vnodes.

I am unable to decipher your proposal.

The property of guaranteed non-recursive shared request is per call site,
it is not global for the life of lock.  As such, I do not understand
what would a proposed flag for lockinit(9) indicate to kern_lock.c,
vs. the currently passed flag to __lockmgr_args(9).  Only specific calls
need to avoid check for td_lk_slocks != 0, not specific locks.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20141103111851.GM53947>