1 files changed, 71 insertions, 0 deletions
diff --git a/debian/patches/95-gl-Take-advantage-of-GLX_MESA_multithread_makecurren.patch b/debian/patches/95-gl-Take-advantage-of-GLX_MESA_multithread_makecurren.patch
new file mode 100644
index 0000000..daabcb6
--- /dev/null
+++ b/debian/patches/95-gl-Take-advantage-of-GLX_MESA_multithread_makecurren.patch
@@ -0,0 +1,71 @@
+From 1085971717af280f6d12a5fbf3d11f8586a74357 Mon Sep 17 00:00:00 2001
+From: Eric Anholt <eric@anholt.net>
+Date: Mon, 31 Jan 2011 20:47:15 -0800
+Subject: [PATCH 15/16] gl: Take advantage of GLX_MESA_multithread_makecurrent
+ to avoid unbinding.
+
+Because of GLX's unfortunate requirement that only one context have a
+thread current at a time, we had to unbind the context, triggering a
+flush, and eating of all the CPU.  With a small tweak to the GLX spec
+by GLX_MESA_multithread_makecurrent, and a small tweak to Mesa that
+consisted mostly of deleting the "is this thread already bound
+elsewhere?" check, we can bind our context to any thread and use it
+safely as long as our usage of it is mutexed, which cairo-gl should
+already be doing.
+
+[  0] before      firefox-talos-gfx   50.260   50.525   0.25%    3/3
+[  0] after       firefox-talos-gfx   32.091   32.422   0.65%    3/3
+(cherry picked from commit 2fae22a3f2914a6e79436bafe94d19100d7cf6bf)
+
+Signed-off-by: Cyril Brulebois <kibi@debian.org>
+---
+ src/cairo-glx-context.c |   12 +++++++++++-
+ 1 files changed, 11 insertions(+), 1 deletions(-)
+
+diff --git a/src/cairo-glx-context.c b/src/cairo-glx-context.c
+index 83963fb..f89fa32 100644
+--- a/src/cairo-glx-context.c
++++ b/src/cairo-glx-context.c
+@@ -52,6 +52,8 @@ typedef struct _cairo_glx_context {
+     Display *display;
+     Window dummy_window;
+     GLXContext context;
++
++    cairo_bool_t has_multithread_makecurrent;
+ } cairo_glx_context_t;
+ 
+ typedef struct _cairo_glx_surface {
+@@ -92,7 +94,9 @@ _glx_release (void *abstract_ctx)
+ {
+     cairo_glx_context_t *ctx = abstract_ctx;
+ 
+-    glXMakeCurrent (ctx->display, None, None);
++    if (!ctx->has_multithread_makecurrent) {
++	glXMakeCurrent (ctx->display, None, None);
++    }
+ }
+ 
+ static void
+@@ -174,6 +178,7 @@ cairo_glx_device_create (Display *dpy, GLXContext gl_ctx)
+     cairo_glx_context_t *ctx;
+     cairo_status_t status;
+     Window dummy = None;
++    const char *glx_extensions;
+ 
+     status = _glx_dummy_ctx (dpy, gl_ctx, &dummy);
+     if (unlikely (status))
+@@ -206,6 +211,11 @@ cairo_glx_device_create (Display *dpy, GLXContext gl_ctx)
+ 	return _cairo_gl_context_create_in_error (status);
+     }
+ 
++    glx_extensions = glXQueryExtensionsString (dpy, DefaultScreen (dpy));
++    if (strstr(glx_extensions, "GLX_MESA_multithread_makecurrent")) {
++	ctx->has_multithread_makecurrent = TRUE;
++    }
++
+     ctx->base.release (ctx);
+ 
+     return &ctx->base.base;
+-- 
+1.7.5.4
+