From: Peter Zijlstra <peterz@infradead.org>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Juri Lelli <juri.lelli@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Will Deacon <will@kernel.org>, Waiman Long <longman@redhat.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Mike Galbraith <efault@gmx.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] locking: rwbase: Take care of ordering guarantee for fastpath reader
Date: Sat, 4 Sep 2021 12:14:29 +0200 [thread overview]
Message-ID: <20210904101429.GB4323@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <YTI2UjKy+C7LeIf+@boqun-archlinux>
On Fri, Sep 03, 2021 at 10:50:58PM +0800, Boqun Feng wrote:
> > * ordering, either is strong enough to provide ACQUIRE order
> > * for the above load of @readers.
> > */
> > rwbase_set_and_save_current_state(state);
> > raw_spin_lock_irqsave(&rtm->wait_lock, flags);
> >
> > while (readers) {
> > ...
> > readers = atomic_read(&rwb->readers);
>
> The above should be _acquire(), right? Pairs with the last reader
> exiting the critical section and dec ->readers to 0. If so, it
> undermines the necessity of the restructure?
This is the one that's followed by set_current_state(), no?
next prev parent reply other threads:[~2021-09-04 10:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 15:06 [RFC] locking: rwbase: Take care of ordering guarantee for fastpath reader Boqun Feng
2021-09-01 18:53 ` Waiman Long
2021-09-01 20:22 ` Davidlohr Bueso
2021-09-02 5:02 ` Boqun Feng
2021-09-02 11:55 ` Peter Zijlstra
2021-09-03 14:50 ` Boqun Feng
2021-09-04 10:12 ` Peter Zijlstra
2021-09-04 10:14 ` Peter Zijlstra [this message]
2021-09-04 10:19 ` Boqun Feng
2021-09-08 11:51 ` Peter Zijlstra
2021-09-08 12:14 ` Peter Zijlstra
2021-09-08 13:00 ` Boqun Feng
2021-09-08 13:08 ` Boqun Feng
2021-09-08 14:41 ` Peter Zijlstra
2021-09-08 14:49 ` Peter Zijlstra
2021-09-08 18:34 ` Davidlohr Bueso
2021-09-08 13:27 ` Boqun Feng
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=20210904101429.GB4323@worktop.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=bigeasy@linutronix.de \
--cc=boqun.feng@gmail.com \
--cc=bristot@redhat.com \
--cc=dave@stgolabs.net \
--cc=efault@gmx.de \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mingo@kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--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).