This patch (re-)gains performance in helgrind, following revision 15207, that
reduced memory use doing SecMap GC, but was slowing down some workloads
(typically, workloads doing a lot of malloc/free).
A significant part of the slowdown came from the clear of the filter,
that was not optimised for big ranges : the filter was working byte
per byte till an 8 alignment. Then working per 8 bytes at a time.
With the patch, the filter clear is done the following way:
* all the bytes till 8 alignement are done together
* then 8 bytes at a time till filter_line alignment (32 bytes)
* then 32 bytes at a time.
Moreover, as the filter cache is small (1024 lines of 32 bytes),
clearing filter for ranges bigger than 32Kb was uselessly checking
several times the same entry. This is now avoided by using a range
check rather than a tag equality check.
As the new filter clear is significanly more complex than the previous simple
algorithm, the old algorithm is kept and used to check the new algorithm
when CHECK_ZSM is defined as 1.
The patch also contains a few micro optimisations and
disables
// VG_(track_die_mem_stack) ( evh__die_mem );
as this had no effect and was somewhat costly.
With this patch, we have almost reached for all perf tests the same
performance as we had before revision 15207. Some tests are still
slightly slower than before the SecMap GC (max 2% difference).
Some tests are now significantly faster (e.g. sarp).
For almost all tests, we are now faster than valgrind 3.10.1.
Details below.
Regtested on x86/amd64/ppc64 (and regtested with all compile time
checks set).
I have also regtested with libreoffice and firefox.
(with firefox, also with CHECK_ZSM set to 1).
Details about performance:
hgtrace = this patch
trunk_untouched = trunk
base_secmap = trunk before secmap GC
valgrind 3.10.1 included for comparison
Measured on core i5 2.53GHz
-- Running tests in perf ----------------------------------------------
-- bigcode1 --
bigcode1 hgtrace :0.14s he: 2.6s (18.4x, -----)
bigcode1 trunk_untouched:0.14s he: 2.6s (18.4x, -0.4%)
bigcode1 base_secmap:0.14s he: 2.6s (18.6x, -1.2%)
bigcode1 valgrind-3.10.1:0.14s he: 2.8s (19.8x, -7.8%)
-- bigcode2 --
bigcode2 hgtrace :0.14s he: 6.3s (44.7x, -----)
bigcode2 trunk_untouched:0.14s he: 6.2s (44.6x, 0.2%)
bigcode2 base_secmap:0.14s he: 6.3s (45.0x, -0.6%)
bigcode2 valgrind-3.10.1:0.14s he: 6.6s (47.1x, -5.4%)
-- bz2 --
bz2 hgtrace :0.64s he:11.3s (17.7x, -----)
bz2 trunk_untouched:0.64s he:11.7s (18.2x, -3.2%)
bz2 base_secmap:0.64s he:11.1s (17.3x, 1.9%)
bz2 valgrind-3.10.1:0.64s he:12.6s (19.7x,-11.3%)
-- fbench --
fbench hgtrace :0.29s he: 3.4s (11.8x, -----)
fbench trunk_untouched:0.29s he: 3.4s (11.7x, 0.6%)
fbench base_secmap:0.29s he: 3.6s (12.4x, -5.0%)
fbench valgrind-3.10.1:0.29s he: 3.5s (12.2x, -3.5%)
-- ffbench --
ffbench hgtrace :0.26s he: 9.8s (37.7x, -----)
ffbench trunk_untouched:0.26s he:10.0s (38.4x, -1.9%)
ffbench base_secmap:0.26s he: 9.8s (37.8x, -0.2%)
ffbench valgrind-3.10.1:0.26s he:10.0s (38.4x, -1.9%)
-- heap --
heap hgtrace :0.11s he: 9.2s (84.0x, -----)
heap trunk_untouched:0.11s he: 9.6s (87.1x, -3.7%)
heap base_secmap:0.11s he: 9.0s (81.9x, 2.5%)
heap valgrind-3.10.1:0.11s he: 9.1s (82.9x, 1.3%)
-- heap_pdb4 --
heap_pdb4 hgtrace :0.13s he:10.7s (82.3x, -----)
heap_pdb4 trunk_untouched:0.13s he:11.0s (84.8x, -3.0%)
heap_pdb4 base_secmap:0.13s he:10.5s (80.8x, 1.8%)
heap_pdb4 valgrind-3.10.1:0.13s he:10.6s (81.8x, 0.7%)
-- many-loss-records --
many-loss-records hgtrace :0.01s he: 1.5s (152.0x, -----)
many-loss-records trunk_untouched:0.01s he: 1.6s (157.0x, -3.3%)
many-loss-records base_secmap:0.01s he: 1.6s (158.0x, -3.9%)
many-loss-records valgrind-3.10.1:0.01s he: 1.7s (167.0x, -9.9%)
-- many-xpts --
many-xpts hgtrace :0.03s he: 2.8s (91.7x, -----)
many-xpts trunk_untouched:0.03s he: 2.8s (94.7x, -3.3%)
many-xpts base_secmap:0.03s he: 2.8s (94.0x, -2.5%)
many-xpts valgrind-3.10.1:0.03s he: 2.9s (97.7x, -6.5%)
-- memrw --
memrw hgtrace :0.06s he: 7.3s (121.2x, -----)
memrw trunk_untouched:0.06s he: 7.2s (120.3x, 0.7%)
memrw base_secmap:0.06s he: 7.1s (117.7x, 2.9%)
memrw valgrind-3.10.1:0.06s he: 8.1s (135.2x,-11.6%)
-- sarp --
sarp hgtrace :0.02s he: 7.6s (378.5x, -----)
sarp trunk_untouched:0.02s he: 8.4s (422.0x,-11.5%)
sarp base_secmap:0.02s he: 8.6s (431.0x,-13.9%)
sarp valgrind-3.10.1:0.02s he: 8.8s (442.0x,-16.8%)
-- tinycc --
tinycc hgtrace :0.20s he:12.4s (62.0x, -----)
tinycc trunk_untouched:0.20s he:12.6s (63.2x, -1.9%)
tinycc base_secmap:0.20s he:12.6s (63.0x, -1.6%)
tinycc valgrind-3.10.1:0.20s he:12.7s (63.5x, -2.3%)
-- Finished tests in perf ----------------------------------------------
== 12 programs, 48 timings =================
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15236 a5019735-40e9-0310-863c-91ae7b9d1cf9
2 files changed
