From: "J. Bruce Fields" <bfields@fieldses.org>
To: NeilBrown <neilb@suse.com>
Cc: Jeff Layton <jlayton@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Martin Wilck <mwilck@suse.de>,
linux-fsdevel@vger.kernel.org,
Frank Filz <ffilzlnx@mindspring.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/5 - V2] locks: avoid thundering-herd wake-ups
Date: Thu, 9 Aug 2018 22:52:51 -0400 [thread overview]
Message-ID: <20180810025251.GO23873@fieldses.org> (raw)
In-Reply-To: <871sb7rnul.fsf@notabene.neil.brown.name>
On Fri, Aug 10, 2018 at 11:50:58AM +1000, NeilBrown wrote:
> You're good at this game!
Everybody's got to have a hobby, mine is pathological posix locking
cases....
> So, because a locker with the same "owner" gets a free pass, you can
> *never* say that any lock which conflicts with A also conflicts with B,
> as a lock with the same owner as B will never conflict with B, even
> though it conflicts with A.
>
> I think there is still value in having the tree, but when a waiter is
> attached under a new blocker, we need to walk the whole tree beneath the
> waiter and detach/wake anything that is not blocked by the new blocker.
If you're walking the whole tree every time then it might as well be a
flat list, I think?
--b.
next prev parent reply other threads:[~2018-08-10 5:20 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-09 2:04 [PATCH 0/5 - V2] locks: avoid thundering-herd wake-ups NeilBrown
2018-08-09 2:04 ` [PATCH 1/5] fs/locks: rename some lists and pointers NeilBrown
2018-08-09 2:04 ` [PATCH 2/5] fs/locks: allow a lock request to block other requests NeilBrown
2018-08-09 2:04 ` [PATCH 3/5] fs/locks: change all *_conflict() functions to return a new enum NeilBrown
2018-08-09 11:09 ` Jeff Layton
2018-08-09 13:09 ` J. Bruce Fields
2018-08-09 23:40 ` NeilBrown
2018-08-10 0:56 ` J. Bruce Fields
2018-08-09 2:04 ` [PATCH 4/5] fs/locks: split out __locks_wake_one() NeilBrown
2018-08-09 2:04 ` [PATCH 5/5] fs/locks: create a tree of dependent requests NeilBrown
2018-08-09 11:17 ` Jeff Layton
2018-08-09 23:25 ` NeilBrown
2018-08-09 14:13 ` J. Bruce Fields
2018-08-09 22:19 ` NeilBrown
2018-08-10 0:36 ` J. Bruce Fields
2018-08-09 17:32 ` [PATCH 0/5 - V2] locks: avoid thundering-herd wake-ups J. Bruce Fields
2018-08-09 22:12 ` NeilBrown
2018-08-10 0:29 ` J. Bruce Fields
2018-08-10 1:50 ` NeilBrown
2018-08-10 2:52 ` J. Bruce Fields [this message]
2018-08-10 3:17 ` NeilBrown
2018-08-10 15:47 ` J. Bruce Fields
2018-08-11 11:56 ` Jeff Layton
2018-08-11 12:35 ` J. Bruce Fields
2018-08-11 11:51 ` Jeff Layton
2018-08-11 12:21 ` J. Bruce Fields
2018-08-11 13:15 ` Jeff Layton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180810025251.GO23873@fieldses.org \
--to=bfields@fieldses.org \
--cc=ffilzlnx@mindspring.com \
--cc=jlayton@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mwilck@suse.de \
--cc=neilb@suse.com \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).