Horton

Re: [HACKERS] Moving relation extension locks out of heavyweight lock manager

Masahiko Sawada <masahiko.sawada@2ndquadrant.com>

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From: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Mahendra Singh Thalor <mahi6run@gmail.com>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Masahiko Sawada <sawada.mshk@gmail.com>, Michael Paquier <michael@paquier.xyz>, Mithun Cy <mithun.cy@enterprisedb.com>, Thomas Munro <thomas.munro@enterprisedb.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2020-03-16T03:26:55Z
Lists: pgsql-hackers

Commits

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  1. Allow page lock to conflict among parallel group members.

  2. Allow relation extension lock to conflict among parallel group members.

  3. Add assert to ensure that page locks don't participate in deadlock cycle.

  4. Assert that we don't acquire a heavyweight lock on another object after

  5. Fix unsafe usage of strerror(errno) within ereport().

On Mon, 16 Mar 2020 at 00:54, Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Sun, Mar 15, 2020 at 6:20 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Sun, Mar 15, 2020 at 4:34 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > >
> > > I have modified 0001 and 0002 slightly,  Basically, instead of two
> > > function CheckAndSetLockHeld and CheckAndReSetLockHeld, I have created
> > > a one function.
> > >
> >
> > +CheckAndSetLockHeld(LOCALLOCK *locallock, bool value)
> >
> > Can we rename the parameter as lock_held, acquired or something like
> > that so that it indicates what it intends to do and probably add a
> > comment for that variable atop of function?
>
> Done
>

I've looked at the patches and ISTM these work as expected.
IsRelationExtensionLockHeld and IsPageLockHeld are used only when
assertion is enabled. So how about making CheckAndSetLockHeld work
only if USE_ASSERT_CHECKING to avoid overheads?

Regards,

--
Masahiko Sawada            http://www.2ndQuadrant.com/
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