Jens Johansen
3e56b7ec3a
By exercising loadComponent more we speedup the loading of the sdk.
This is going to be noticable when executing small scripts.
On my machine execution of a hello-world script is speed up by ~15-20%.
More data from local experiments:
Before:
$ perf stat -r 25 -d out/ReleaseX64/dart hello.dart
Performance counter stats for 'out/ReleaseX64/dart hello.dart' (25 runs):
389.268166 task-clock:u (msec) # 2.035 CPUs utilized ( +- 0.91% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
19,278 page-faults:u # 0.050 M/sec ( +- 0.65% )
979,345,922 cycles:u # 2.516 GHz ( +- 1.31% ) (48.75%)
1,120,493,995 instructions:u # 1.14 insn per cycle ( +- 0.73% ) (61.28%)
207,470,248 branches:u # 532.975 M/sec ( +- 0.84% ) (60.76%)
4,439,025 branch-misses:u # 2.14% of all branches ( +- 1.00% ) (61.00%)
387,461,284 L1-dcache-loads:u # 995.358 M/sec ( +- 1.38% ) (49.12%)
18,764,375 L1-dcache-load-misses:u # 4.84% of all L1-dcache hits ( +- 2.94% ) (26.43%)
5,713,192 LLC-loads:u # 14.677 M/sec ( +- 2.13% ) (25.71%)
1,266,848 LLC-load-misses:u # 22.17% of all LL-cache hits ( +- 3.74% ) (37.01%)
0.191278504 seconds time elapsed ( +- 1.10% )
$ runxtimes 25 sudo chrt -f 99 /usr/bin/time -f "%e" out/ReleaseX64/dart hello.dart > /dev/null 2>> before.txt
After:
$ perf stat -r 25 -d out/ReleaseX64/dart hello.dart
Performance counter stats for 'out/ReleaseX64/dart hello.dart' (25 runs):
311.248543 task-clock:u (msec) # 1.981 CPUs utilized ( +- 0.91% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
18,055 page-faults:u # 0.058 M/sec ( +- 0.84% )
727,169,504 cycles:u # 2.336 GHz ( +- 1.66% ) (48.89%)
875,097,166 instructions:u # 1.20 insn per cycle ( +- 0.74% ) (60.69%)
164,966,288 branches:u # 530.015 M/sec ( +- 0.82% ) (59.50%)
3,403,794 branch-misses:u # 2.06% of all branches ( +- 0.93% ) (59.61%)
272,404,305 L1-dcache-loads:u # 875.199 M/sec ( +- 1.53% ) (47.62%)
11,115,851 L1-dcache-load-misses:u # 4.08% of all L1-dcache hits ( +- 1.70% ) (27.55%)
4,154,542 LLC-loads:u # 13.348 M/sec ( +- 2.22% ) (26.40%)
1,225,723 LLC-load-misses:u # 29.50% of all LL-cache hits ( +- 2.75% ) (37.49%)
0.157151348 seconds time elapsed ( +- 1.12% )
$ runxtimes 25 sudo chrt -f 99 /usr/bin/time -f "%e" out/ReleaseX64/dart hello.dart > /dev/null 2>> after.txt
$ ministat -A before.txt after.txt
x before.txt
+ after.txt
N Min Max Median Avg Stddev
x 25 0.17 0.2 0.18 0.1816 0.008
+ 25 0.13 0.19 0.15 0.152 0.013844373
Difference at 95.0% confidence
-0.0296 +/- 0.00643101
-16.2996% +/- 3.5413%
(Student's t, pooled s = 0.0113063)
Notes:
$ type runxtimes
runxtimes is a function
runxtimes ()
{
number=$1;
shift;
for i in `seq $number`;
do
$@;
done
}
Change-Id: I760759976136195da00e3719663bdadbfe962e70
Reviewed-on: https://dart-review.googlesource.com/c/82581
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
This package hosts VM specific Dart code and helper scripts.