From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
linux-kernel@vger.kernel.org, Phil Auld <pauld@redhat.com>
Subject: Re: [PATCH 3/5] locking/rwsem: Enable reader optimistic lock stealing
Date: Mon, 7 Dec 2020 19:53:14 -0800 [thread overview]
Message-ID: <20201208035314.rwz72kgn5apr2whm@linux-p48b> (raw)
In-Reply-To: <20201118030429.23017-4-longman@redhat.com>
On Tue, 17 Nov 2020, Waiman Long wrote:
>If the optimistic spinning queue is empty and the rwsem does not have
>the handoff or write-lock bits set, it is actually not necessary to
>call rwsem_optimistic_spin() to spin on it. Instead, it can steal the
>lock directly as its reader bias is in the count already. If it is
>the first reader in this state, it will try to wake up other readers
>in the wait queue.
>
>Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
next prev parent reply other threads:[~2020-12-08 4:19 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-18 3:04 [PATCH 0/5] locking/rwsem: Rework reader optimistic spinning Waiman Long
2020-11-18 3:04 ` [PATCH 1/5] locking/rwsem: Pass the current atomic count to rwsem_down_read_slowpath() Waiman Long
2020-11-18 3:04 ` [PATCH 2/5] locking/rwsem: Prevent potential lock starvation Waiman Long
2020-11-20 14:44 ` Peter Zijlstra
2020-11-20 17:27 ` Waiman Long
2020-11-18 3:04 ` [PATCH 3/5] locking/rwsem: Enable reader optimistic lock stealing Waiman Long
2020-11-20 14:36 ` Peter Zijlstra
2020-11-20 17:26 ` Waiman Long
2020-12-08 3:53 ` Davidlohr Bueso [this message]
2020-11-18 3:04 ` [PATCH 4/5] locking/rwsem: Wake up all waiting readers if RWSEM_WAKE_READ_OWNED Waiman Long
2020-11-18 4:53 ` Davidlohr Bueso
2020-11-19 18:37 ` Waiman Long
2020-11-18 3:04 ` [RFC PATCH 5/5] locking/rwsem: Remove reader optimistic spinning Waiman Long
2020-11-18 5:35 ` Davidlohr Bueso
2020-11-19 18:40 ` Waiman Long
2020-11-20 13:11 ` David Laight
2020-11-20 17:04 ` Waiman Long
2020-11-20 17:37 ` David Laight
2020-11-20 21:38 ` Davidlohr Bueso
2020-11-21 11:50 ` David Laight
2020-11-20 14:44 ` Peter Zijlstra
2020-11-20 22:39 ` Waiman Long
2020-11-20 14:42 ` Peter Zijlstra
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=20201208035314.rwz72kgn5apr2whm@linux-p48b \
--to=dave@stgolabs.net \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mingo@redhat.com \
--cc=pauld@redhat.com \
--cc=peterz@infradead.org \
--cc=will@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).