From: Waiman Long <waiman.long@hpe.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <kernellwp@gmail.com>, <linux-kernel@vger.kernel.org>,
Wanpeng Li <wanpeng.li@hotmail.com>,
Ingo Molnar <mingo@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>
Subject: Re: [PATCH v2] locking/pvqspinlock: restore/set vcpu_hashed state after failing adaptive locking spinning
Date: Thu, 14 Jul 2016 10:56:30 -0400 [thread overview]
Message-ID: <5787A81E.7080700@hpe.com> (raw)
In-Reply-To: <20160714112648.GG30909@twins.programming.kicks-ass.net>
On 07/14/2016 07:26 AM, Peter Zijlstra wrote:
> On Thu, Jul 14, 2016 at 04:15:56PM +0800, Wanpeng Li wrote:
>> In this case, lock holder inserts the pv_node of queue head into the
>> hash table and set _Q_SLOW_VAL unnecessary. This patch avoids it by
>> restoring/setting vcpu_halted state after failing adaptive locking
> ^^^^^^
>> spinning.
>>
>> - WRITE_ONCE(pn->state, vcpu_halted);
>> + WRITE_ONCE(pn->state, vcpu_hashed);
> ^^^^^^
>
> The Changelog meant so say vcpu_hashed, surely?
Do you have chance to review the "Fix missed PV wakeup & support PPC"
patch (https://lkml.org/lkml/2016/5/31/677) that I had sent out a while
ago? That patch addressed a similar pv_hash leakage and collision problem.
Cheers,
Longman
next prev parent reply other threads:[~2016-07-14 14:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-14 8:15 [PATCH v2] locking/pvqspinlock: restore/set vcpu_hashed state after failing adaptive locking spinning Wanpeng Li
2016-07-14 11:26 ` Peter Zijlstra
2016-07-14 11:28 ` Wanpeng Li
2016-07-14 14:56 ` Waiman Long [this message]
2016-08-10 18:05 ` [tip:locking/core] locking/pvqspinlock: Fix double hash race tip-bot for Wanpeng Li
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=5787A81E.7080700@hpe.com \
--to=waiman.long@hpe.com \
--cc=dave@stgolabs.net \
--cc=kernellwp@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=wanpeng.li@hotmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.