[Mesa-dev] [PATCH 0/4] improve buffer cache and reuse

[James Xiong]

From: "Xiong, James" <james.xiong at intel.com>

With the current implementation, brw_bufmgr may round up a request
size to the next bucket size, result in 25% more memory allocated in
the worst senario. For example:
Request size    Actual size
32KB+1Byte      40KB
.
8MB+1Byte       10MB
.
96MB+1Byte      112MB
This series align the buffer size up to page instead of a bucket size
to improve memory allocation efficiency.

Performance and memory usage were measured on a gen9 platform using
Basemark ES3, GfxBench 4 and 5, each test case ran 6 times.

Basemark ES3
score                            peak memory size(KB)
before    after   diff           before  after   diff
max avg   max avg max    avg
22  21    23  21  2.83%  1.21%   409928  395573  -14355
20  20    20  20  0.53%  0.41%			

GfxBench 4.0
scorepeak memory size(KB)
score                                   peak memory size(KB) 
before      after       diff            before  after   diff
max   avg   max   avg   max     avg
584   577   586   583   0.45%   1.02%   566489  539699  -26791
728   727   727   726	-0.03%  -0.16%  614730  586794  -27936
1604  1144  1650  1202	2.81%   4.86%   439220  411596  -27624
2711  2222  2718  2152  0.25%   -3.25%  126065  121398  -4667
1218  1213  1212  1154  -0.53%  -5.10%  54153   53868   -285
106   104   106   103   0.85%   -1.66%  12730   12666   -64
1732  1709  1740  1728  0.49%   1.11%   475716  447726  -27990
3051  2969  3066  3047  0.50%   2.55%   154169  148962  -5207
2626  2607  2626  2625  0.00%   0.70%   84119   83150   -969
211   208   208   205   -1.26%  -1.21%  39924   39667   -257


GfxBench 5.0
score                               peak memory size(KB)
before    after     diff            before   after    diff
max  avg  max  avg  max     avg      
260  258  259  256  -0.39%  -0.85%  1111037  1013520  -97517
298  295  298  297  0.00%   0.45%   1143593  1040844  -102749

Xiong, James (4):
  i965/drm: Reorganize code for the next patch
  i965/drm: Round down buffer size and calculate the bucket index
  i965/drm: Searching for a cached buffer for reuse
  i965/drm: Purge the bucket when its cached buffer is evicted

 src/mesa/drivers/dri/i965/brw_bufmgr.c | 139 ++++++++++++++++++---------------
 src/util/list.h                        |   5 ++
 2 files changed, 79 insertions(+), 65 deletions(-)

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2.7.4