From: Peter Zijlstra <peterz@infradead.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: mingo@kernel.org, akpm@linux-foundation.org, jack@suse.cz,
kirill.shutemov@linux.intel.com, ldufour@linux.vnet.ibm.com,
mhocko@suse.com, mgorman@techsingularity.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 -tip 0/6] locking: Introduce range reader/writer lock
Date: Thu, 20 Apr 2017 21:10:00 +0200 [thread overview]
Message-ID: <20170420191000.GB6873@worktop> (raw)
In-Reply-To: <20170420183646.GF20746@linux-80c1.suse>
On Thu, Apr 20, 2017 at 11:36:46AM -0700, Davidlohr Bueso wrote:
> On Thu, 20 Apr 2017, Peter Zijlstra wrote:
> >Those are about avoiding actually going to sleep and having to be woken
> >up (and waiting to become running) again, which is a long time.
>
> Yes, which is why I was thinking of ways to mitigate this. Ie: for
> blocked writers with low counts of 'blocking_ranges'.
So for this it would be good to have a better understanding of that
whole fairness / interval order crud.
IIRC rwsem only does writer-writer stealing and opt spinning, right? And
for stealing it doesn't matter how many are pending, just that you are
running and they are not (and then you get fairness issues and handover
etc..).
For opt spinning we need to specifically know who would be next in
order, again, doesn't matter how many, just who's next.
next prev parent reply other threads:[~2017-04-20 19:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 8:46 [PATCH v2 -tip 0/6] locking: Introduce range reader/writer lock Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 1/6] interval-tree: Build unconditionally Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 2/6] locking: Introduce range reader/writer lock Davidlohr Bueso
2017-04-06 9:01 ` Laurent Dufour
2017-04-06 16:50 ` Davidlohr Bueso
2017-04-13 8:07 ` Laurent Dufour
2017-04-13 8:38 ` Jan Kara
2017-04-13 8:58 ` Laurent Dufour
2017-04-06 10:24 ` Peter Zijlstra
2017-04-18 13:57 ` Laurent Dufour
2017-04-20 16:01 ` Davidlohr Bueso
2017-04-21 7:00 ` Laurent Dufour
2017-04-06 8:46 ` [PATCH 3/6] locking/locktorture: Fix rwsem reader_delay Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 4/6] locking/locktorture: Fix num reader/writer corner cases Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 5/6] locking/locktorture: Support range rwlocks Davidlohr Bueso
2017-04-06 8:46 ` [PATCH 6/6] staging/lustre: Use generic range rwlock Davidlohr Bueso
2017-04-07 10:08 ` Dilger, Andreas
2017-04-19 12:37 ` [PATCH v2 -tip 0/6] locking: Introduce range reader/writer lock Peter Zijlstra
2017-04-20 17:13 ` Davidlohr Bueso
2017-04-20 17:53 ` Peter Zijlstra
2017-04-20 18:36 ` Davidlohr Bueso
2017-04-20 19:10 ` Peter Zijlstra [this message]
2017-05-15 9:19 ` Davidlohr Bueso
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=20170420191000.GB6873@worktop \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=dave@stgolabs.net \
--cc=jack@suse.cz \
--cc=kirill.shutemov@linux.intel.com \
--cc=ldufour@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@suse.com \
--cc=mingo@kernel.org \
/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).