Eric Anholt c8e0f93a38 drm/i915: Replace a calloc followed by copying data over it with malloc.
Execbufs involve quite a bit of payload, to the extent that cache misses
show up in the profiles here, and a suspicion that some of those cachelines
may get evicted and then reloaded in the subsequent copy.

This is still abstracted like drm_calloc_large since we want to check for
size overflow, and because we want to choose between kmalloc and vmalloc
on the fly.  cairo's interface for malloc-with-calloc's-args was used as
the model.

Signed-off-by: Eric Anholt <eric@anholt.net>
2009-11-25 06:36:21 -08:00
..
2009-10-28 15:26:56 +10:00
2009-03-28 20:22:18 -04:00
2009-08-31 09:37:22 +10:00

************************************************************
* For the very latest on DRI development, please see:      *
*     http://dri.freedesktop.org/                          *
************************************************************

The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).

The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:

    1. The DRM provides synchronized access to the graphics hardware via
       the use of an optimized two-tiered lock.

    2. The DRM enforces the DRI security policy for access to the graphics
       hardware by only allowing authenticated X11 clients access to
       restricted regions of memory.

    3. The DRM provides a generic DMA engine, complete with multiple
       queues and the ability to detect the need for an OpenGL context
       switch.

    4. The DRM is extensible via the use of small device-specific modules
       that rely extensively on the API exported by the DRM module.


Documentation on the DRI is available from:
    http://dri.freedesktop.org/wiki/Documentation
    http://sourceforge.net/project/showfiles.php?group_id=387
    http://dri.sourceforge.net/doc/

For specific information about kernel-level support, see:

    The Direct Rendering Manager, Kernel Support for the Direct Rendering
    Infrastructure
    http://dri.sourceforge.net/doc/drm_low_level.html

    Hardware Locking for the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/hardware_locking_low_level.html

    A Security Analysis of the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/security_low_level.html