From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Howells <dhowells@redhat.com>
Subject: Re: [RFC PATCH 02/21] Add a prelocked wake-up
Date: Tue, 15 Oct 2019 23:33:16 +0100
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To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: dhowells@redhat.com, Tim Chen <tim.c.chen@linux.intel.com>, Kan Liang <kan.liang@intel.com>, Casey Schaufler <casey@schaufler-ca.com>, Stephen Smalley <sds@tycho.nsa.gov>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Nicolas Dichtel <nicolas.dichtel@6wind.com>, raven@themaw.net, Christian Brauner <christian@brauner.io>, keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-block <linux-block@vger.kernel.org>, LSM List <linux-security-module@vger.kernel.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, Linux API <linux-api@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Linus Torvalds <torvalds@linux-foundation.org> wrote:

> > Add a wakeup call for a case whereby the caller already has the waitqueue
> > spinlock held.
> 
> That naming is crazy.

Sorry, yeah.  This is a bit hacked together at the moment and needs some more
tidying up.  I've had a lot of problems with performance regressions of up to
40% from seemingly simple changes involving moving locks around - it turns out
that the problem was that I was running with kasan enabled.

David