System Environment:
--------------------------

--Platform: i965

--Architecture(32-bit,64-bit,compatiblity): all

--2D driver:
commit 224c36cc14a7552bc5df793ad582f0ea5349eb1e

--3D driver:
commit 7233eabaf0072b7c50e4f26ec33738b5b89aad20

--Xserver:
commit 267352579612155adfd4743432d6569b2cdeebde

--Drm
commit 1021799b6ca6b195ad2d5f002e45668f69c44651

--Kernel:
2.6.23.1


Bug detailed description:
-------------------------
run glean test case texCombine will get segment fault:
[root@x-q965 bin]# ./glean -o -r test -t texCombine
intel_bufmgr_ttm.c:644: Error mapping buffer temporary VBO: Cannot allocate memory .
Segmentation fault (core dumped)

backtrace:
(gdb) bt
#0  0x4698f68c in memcpy () from /lib/libc.so.6
#1  0xb7b1448a in copy_array_to_vbo_array (brw=Variable "brw" is not available.
) at brw_draw_upload.c:227
#2  0xb7b14d01 in brw_upload_vertices (brw=0x8109908, min_index=0, max_index=3)
    at brw_draw_upload.c:414
#3  0xb7b1403e in brw_draw_prims (ctx=0x8109908, arrays=0x813e1a0,
    prim=0x813ccfc, nr_prims=1, ib=0x0, min_index=0, max_index=3)
    at brw_draw.c:315
#4  0xb7bcb2e1 in vbo_exec_vtx_flush (exec=0x813cbd8)
    at vbo/vbo_exec_draw.c:215
#5  0xb7bc6b08 in vbo_exec_FlushVertices (ctx=0x8109908, flags=1)
    at vbo/vbo_exec_api.c:700
#6  0xb7c73ab1 in _mesa_ReadPixels (x=0, y=0, width=1, height=1, format=6408,
    type=5126, pixels=0xbfb7c83c) at main/drawpix.c:276
#7  0x08095147 in GLEAN::TexCombineTest::RunSingleTextureTest (this=0x80ed2e0,
    machine=@0x80ed31c, testParams=0x80eb000, r=@0x8135238, w=@0xbfb7ca28)
    at ttexcombine.cpp:1133
#8  0x0809552c in GLEAN::TexCombineTest::runOne (this=0x80ed2e0, r=@0x8135238,
    w=@0xbfb7ca28) at ttexcombine.cpp:1501
#9  0x0805b651 in GLEAN::BaseTest<GLEAN::BasicResult>::run (this=0x80ed2e0,
    environment=@0xbfb7cab0) at tbase.h:290
#10 0x0805443b in main (argc=6, argv=0xbfb7cbf4) at main.cpp:128



Reproduce steps:
----------------
1. start X
2. ./glean -r log -t texCombine


Current result:
----------------
segment fault


Expected result:
----------------
glean case texCombine should pass without segment fault