<html>
    <head>
      <base href="https://bugs.freedesktop.org/">
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [r600g, bisected] regression: NI/Turks WebGL (FishGL) massive speed decrease ~33%"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=97273">97273</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[r600g, bisected] regression: NI/Turks WebGL (FishGL) massive speed decrease ~33%
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>Mesa
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>git
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>x86-64 (AMD64)
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (All)
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>Drivers/Gallium/r600
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>dri-devel@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>Dieter@nuetzel-hh.de
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>dri-devel@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Current Mesa (git-3f100b7) and some stable versions show massive speed decrease
on FishGL (WebGL) demo with konqueror 4.14.8 (KDE 4.14.9).

<a href="http://www.fishgl.com/">http://www.fishgl.com/</a>

look at the aquarium: ~60 fps -> ~40 fps
look from inside (diver): ~30 fps -> ~20 fps

I've bisected it to:

/opt/mesa> git bisect good                                                     
                  3735a925ef5692c836c4d26d6adee370dae1c2b0 is the first bad
commit
commit 3735a925ef5692c836c4d26d6adee370dae1c2b0
Author: Nicolai Hähnle <<a href="mailto:nicolai.haehnle@amd.com">nicolai.haehnle@amd.com</a>>
Date:   Wed Jun 8 13:24:14 2016 +0200

    st/mesa: cache staging texture for glReadPixels

    v2: add ST_DEBUG flag for disabling (suggested by Ilia)

    Reviewed-by: Marek Olšák <<a href="mailto:marek.olsak@amd.com">marek.olsak@amd.com</a>> (v1)

:040000 040000 f3adb5adc43e4def32bd23896489520d8cae84c6
72b374e2221e9cc1306d7bfacf39780ec5e42d36 Msrc

<a href="https://cgit.freedesktop.org/mesa/mesa/log/?ofs=1150">https://cgit.freedesktop.org/mesa/mesa/log/?ofs=1150</a>

Revert didn't went smooth, so I've commented:

diff --git a/src/mesa/state_tracker/st_cb_readpixels.c
b/src/mesa/state_tracker/st_cb_readpixels.c
index 8eb839d..3af9530 100644
--- a/src/mesa/state_tracker/st_cb_readpixels.c
+++ b/src/mesa/state_tracker/st_cb_readpixels.c
@@ -329,7 +329,7 @@ try_cached_readpixels(struct st_context *st, struct
st_renderbuffer *strb,
    struct pipe_resource *src = strb->texture;
    struct pipe_resource *dst = NULL;

-   if (ST_DEBUG & DEBUG_NOREADPIXCACHE)
+ /*  if (ST_DEBUG & DEBUG_NOREADPIXCACHE) */
       return NULL;

    /* Reset cache after invalidation or switch of parameters. */

After that speed was 'normal'.</pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are the assignee for the bug.</li>
      </ul>
    </body>
</html>