Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
From:   "NeilBrown" <neilb@suse.de>
To:     "Darrick J. Wong" <djwong@kernel.org>
Cc:     "Andreas Dilger" <adilger@dilger.ca>,
        "Dave Chinner" <david@fromorbit.com>,
        "Al Viro" <viro@zeniv.linux.org.uk>,
        "Linux NFS Mailing List" <linux-nfs@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org,
        "LKML" <linux-kernel@vger.kernel.org>,
        "Daire Byrne" <daire@dneg.com>,
        "Andreas Dilger" <adilger.kernel@dilger.ca>
Subject: Re: [PATCH/RFC] VFS: support parallel updates in the one directory.
In-reply-to: <20220224233848.GC8269@magnolia>
References: <164568221518.25116.18139840533197037520@noble.neil.brown.name>,
 <893053D7-E5DD-43DB-941A-05C10FF5F396@dilger.ca>,
 <20220224233848.GC8269@magnolia>
Date:   Mon, 28 Feb 2022 11:55:47 +1100
Message-id: <164600974741.15631.8678502963654197325@noble.neil.brown.name>
Precedence: bulk

On Fri, 25 Feb 2022, Darrick J. Wong wrote:
> On Thu, Feb 24, 2022 at 09:31:28AM -0700, Andreas Dilger wrote:
> > On Feb 23, 2022, at 22:57, NeilBrown <neilb@suse.de> wrote:
> > >=20
> > > for i in {1..70}; do ( for j in {1000..8000}; do touch $j; rm -f $j ; d=
one ) & done
>=20
> I think you want something faster here, like ln to hardlink an existing
> file into the directory.
>=20

And probably written in C too..

=20
> (I am also not a fan of "PAR_UPDATE", since 'par' is already an English
> word that doesn't mean 'parallel'.)

:-)
We already have DCACHE_PAR_LOOKUP for parallel lookups in a directory
(though it is really a lock bit and I think should be named as soch).
So it made sense to use DCACHE_PAR_UPDATE for parallel updates.
And then S_PAR_UPDATE for the inode flag to enable this seemed logical.

But I agree that these names are sub-par :-)

NeilBrown