Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20180619082445.11062-1-thellstrom@vmware.com> <20180619082445.11062-3-thellstrom@vmware.com>
 <CAF6AEGubXRVL-PA7TUvW-oF3tTL=oaQ4F+AD_AiX=wUjxCov1g@mail.gmail.com> <9c07b391c16db8b0c788afd4692cc8191baff1aa.camel@vmware.com>
In-Reply-To: <9c07b391c16db8b0c788afd4692cc8191baff1aa.camel@vmware.com>
From:   Rob Clark <robdclark@gmail.com>
Date:   Thu, 17 Jan 2019 07:47:34 -0500
Message-ID: <CAF6AEGvLOKOScQFMHVAFweGDnbR1E3ORqzH6mymJ60rTXkZEfw@mail.gmail.com>
Subject: Re: [PATCH v4 2/3] locking: Implement an algorithm choice for
 Wound-Wait mutexes
To:     Thomas Hellstrom <thellstrom@vmware.com>
Cc:     "corbet@lwn.net" <corbet@lwn.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "peterz@infradead.org" <peterz@infradead.org>,
        "dave@stgolabs.net" <dave@stgolabs.net>,
        "josh@joshtriplett.org" <josh@joshtriplett.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "linaro-mm-sig@lists.linaro.org" <linaro-mm-sig@lists.linaro.org>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "seanpaul@chromium.org" <seanpaul@chromium.org>,
        Pv-drivers <Pv-drivers@vmware.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "gustavo@padovan.org" <gustavo@padovan.org>,
        "maarten.lankhorst@linux.intel.com" 
        <maarten.lankhorst@linux.intel.com>,
        Linux-graphics-maintainer <Linux-graphics-maintainer@vmware.com>,
        "kstewart@linuxfoundation.org" <kstewart@linuxfoundation.org>,
        "paulmck@linux.vnet.ibm.com" <paulmck@linux.vnet.ibm.com>,
        "airlied@linux.ie" <airlied@linux.ie>,
        "pombredanne@nexb.com" <pombredanne@nexb.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jan 16, 2019 at 11:49 AM Thomas Hellstrom <thellstrom@vmware.com> wrote:
>
> Hi,
>
> On Wed, 2019-01-16 at 09:24 -0500, Rob Clark wrote:
> > So, I guess this is to do w/ the magic of merge commits, but it looks
> > like the hunk changing the crtc_ww_class got lost:
>
> So what happened here is that this commit changed it to
> DEFINE_WD_CLASS
> and the following commit changed it back again to
> DEFINE_WW_CLASS
> so that the algorithm change and only that came with the last commit.
> Apparently the history of that line got lost when merging since the
> merge didn't change it; git blame doesn't show it changed, but when
> looking at the commit history in gitk it's all clear. I guess that's a
> feature of git.
>
> The modeset locks now use true wound-wait rather than wait-die.

ahh, ok, that makes sense.  Thanks for clearing up my confusion.

BR,
-R