Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs

From: Philip Martin
Date: Thu Feb 05 2004 - 09:40:21 EST


Nick Piggin <piggin@xxxxxxxxxxxxxxx> writes:

> Sorry, I mean what is it that you are timing?

It's a bit of software (Subversion) built using "make -j4". It
consists of a little over 200 C files compiled to object code, then
linked to about a dozen shared libraries, and finally linked to create
over a dozen executables. It uses libtool, so each compile/link
involves running a bit of shell code before runing gcc. It lends
itself to parallel builds, on 2.4 there is little difference in the
build time using -j2, -j4, -j8. The source code is about 16MB and the
object/library/executable about 28MB.

>>This is the profile for 2.6.2, it is very much like 2.6.1
>>
>>248.07user 118.81system 3:42.00elapsed 165%CPU (0avgtext+0avgdata 0maxresident)k
>>0inputs+0outputs (434major+3770493minor)pagefaults 0swaps
>
> If you get time, could you test the patch I sent you?

Your patch doesn't apply to plain 2.6.2. I got 2.6.2-mm1 and it looks
like that already includes your patch, correct? This is what I got
for 2.6.2-mm1

247.02user 118.33system 3:51.24elapsed 157%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (176major+3771994minor)pagefaults 0swaps

so it's not really an improvement on plain 2.6.2.

--
Philip Martin
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