Parrot 6.6.0 "Parrothead" | parrot.org/ | Log: irclog.perlgeek.de/parrot | #parrotsketch meeting Tuesday 19:30 UTC
Set by moderator on 23 July 2014.
00:04 rurban1 joined 01:36 FROGGS_ joined 02:11 kid51_ joined 05:13 bighugedog joined 05:53 zby_home joined 07:30 basiliscos joined 10:52 kid51 joined 11:53 bighugedog joined 14:01 Chirag joined 14:28 rurban1 joined 16:41 Chirag joined, basiliscos joined
Chirag rurban: my test shows pcc-gh1083 (parrot's repo) to be 0.5% slower than current master 16:48
gist.github.com/ZYROz/685f80d5df46468b2ba0 16:49
rurban that's bad. 64bit linux, right? 16:59
Chirag yes 17:00
rurban cache misses probably, as the .text segment is now a bit bigger
so you probably got a smaller cpu cache
Chirag yes
rurban this needs to be tested with cachegrind 17:01
Chirag on my machine itself?
rurban yes 17:02
Chirag i will do it
rurban let's see if the cache misses relate to the slowness, or if it's something else 17:03
Chirag hmm.. I am now looking at how to use cachegrind 17:04
do I give bench.sh to cachegrind (valgrind tool) ? 17:09
rurban: gist.github.com/ZYROz/21f5a6734dd26d86ef74 17:26
rurban very interesting. I see no differences at all. which is good. 17:29
Chirag so its the cache misses? 17:30
rurban no, it's not 17:31
Chirag then, what do you figure?
rurban i have no idea yet, what else it could be. but that it;s not the cache sounds good. Which means we can merge it
Chirag hmm.. do you have a machine with linux-64bit? 17:32
rurban yes, yours is 32bit?
I see, sorry
Chirag no its 64 bit ubuntu but 3gb ram
rurban I will try to find a real 32bit machine 17:33
Chirag 32 bit helps to judge better, is it? 17:34
rurban yes, I'll try my old ppc machine 17:35
I'm not worried about a single 0.,5% slowdown if the general speed up is > 1%
I was only worried about too much cache misses with a bigger .text segment 17:36
Chirag hmm.. and also do you think it would help to check if all methods in args.c actually require direct calling? is it possible that a VTABLE redirection gives better speed for some?
rurban There's no realistic chance that VTABLE redirection can be faster than direct calls 17:37
Chirag oh.. alright 17:38
rurban Only if the call_object is really hot, but we replaced all call_object calls, and call_object is still hot as it is the 2nd arg
Chirag ok.. 17:39
rurban Now there's no need to keep the call_object vtable in the cache as it's never used 17:40
Chirag maybe I should test my previous tasks now 17:53
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