Re: [PATCH tip/core/rcu] Reduce overhead of cond_resched() checks for RCU

From: Dave Hansen
Date: Mon Jun 23 2014 - 12:55:28 EST


This still has a regression. Commit 1ed70de (from Paul's git tree),
gets a result of 52231880. If I back up two commits to v3.16-rc1 and
revert ac1bea85 (the original culprit) the result goes back up to 57308512.

So something is still going on here.

I'll go back and compare the grace period ages to see if I can tell what
is going on.

--

root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s30
testcase:Separate file open/close
warmup
min:319787 max:386071 total:57464989
min:307235 max:351905 total:53289241
min:291765 max:342439 total:51364514
min:297948 max:349214 total:52552745
min:294950 max:340132 total:51586179
min:290791 max:339958 total:50793238
measurement
min:298851 max:346868 total:51951469
min:292879 max:340704 total:50817269
min:305768 max:347381 total:52655149
min:301046 max:345616 total:52449584
min:300428 max:345293 total:52021166
min:293404 max:337973 total:51012206
min:303569 max:348191 total:52713179
min:305523 max:357448 total:53707053
min:307040 max:356937 total:53271883
min:302134 max:347923 total:52477496
min:297823 max:340488 total:51884417
min:286981 max:338246 total:50496850
min:295920 max:349405 total:51792563
min:302749 max:343780 total:52305074
min:298497 max:345208 total:52035318
min:291393 max:332195 total:50163093
min:303561 max:353396 total:52983515
min:301613 max:352988 total:53029200
min:300693 max:343726 total:52057334
min:296801 max:352408 total:52028824
min:304834 max:358236 total:53526191
min:297933 max:338351 total:51578481
min:299571 max:341679 total:51817941
min:308225 max:354075 total:53760098
min:296262 max:346965 total:51856596
min:309196 max:356432 total:53455141
min:295604 max:341814 total:51449366
min:296931 max:345961 total:52051944
min:300533 max:350304 total:52652951
min:299887 max:350764 total:52955064
average:52231880
root@bigbox:~/will-it-scale# uname -a
Linux bigbox 3.16.0-rc1-00002-g1ed70de #176 SMP Mon Jun 23 09:04:02 PDT
2014 x86_64 x86_64 x86_64 GNU/Linux


root@bigbox:~/will-it-scale# ./open1_processes -t 160 -s 30
testcase:Separate file open/close
warmup
min:346853 max:416035 total:62412724
min:281766 max:344178 total:52207349
min:311187 max:374918 total:57149451
min:326309 max:391061 total:60200366
min:310327 max:375619 total:56744357
min:323336 max:393415 total:59619164
measurement
min:323934 max:393718 total:59665843
min:307247 max:368313 total:55681436
min:318210 max:378048 total:57849321
min:314494 max:383884 total:57741073
min:316497 max:385223 total:58565045
min:320490 max:397636 total:59003133
min:318695 max:391712 total:57789360
min:304368 max:378540 total:56412216
min:314609 max:384462 total:58298008
min:317235 max:384205 total:58812490
min:323556 max:388014 total:59468492
min:301011 max:362664 total:55381779
min:301113 max:364712 total:55375445
min:311730 max:369336 total:56640530
min:316951 max:381341 total:58649244
min:317077 max:383943 total:58132878
min:316970 max:390127 total:59039489
min:315895 max:375937 total:57404755
min:295500 max:346523 total:53086962
min:310882 max:371923 total:56612144
min:321837 max:390544 total:59651640
min:303481 max:368716 total:56135908
min:306437 max:367658 total:56388659
min:307343 max:373645 total:56893136
min:298703 max:358090 total:54152268
min:319162 max:386583 total:58999429
min:304881 max:361968 total:55286607
min:311034 max:381100 total:57846182
min:312786 max:378270 total:57964383
min:311740 max:367481 total:56327526
average:57308512
root@bigbox:~/will-it-scale# uname -a
Linux bigbox 3.16.0-rc1-dirty #177 SMP Mon Jun 23 09:13:59 PDT 2014
x86_64 x86_64 x86_64 GNU/Linux
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/