[nzlug] Kernel this, Kernel that

[Glenn Enright]

On Tuesday 26 September 2006 19:23, Glenn Enright wrote:
> > For the OP, Ubuntu recently did actual measurements on this -- see
> > their development list for details -- and found that there was less
> > difference than the level of measurement error between different
> > levels of optimization.

I have performed some similar tests on my gentoo 2006 system with 
gcc4.1.1. It consists of a Abit IS7 MB with an Intel P4 2600C, 512MB 
RAM in Dual Chanel mode, and a couple of Seagate SATA disks. Tests were 
performed using 2.6.18 kernel as test target. Aside from the below 
changes, all test builds used exactly the same config, in fact the same 
one as I use for my stable kernel.

run 1: CONFIG_M486=y, CONFIG_X86_GENERIC=y
	(CFLAGS=-march=i486 -mtune=i486)

run 2: CONFIG_MPENTIUM4=y, CONFIG_X86_GENERIC not set
	(CFLAGS=-march=i686 -mtune=pentium4)

run 3: CONFIG_MPENTIUM4=y, CONFIG_X86_GENERIC not set, 
	(CFLAGS=-march=pentium4 -mtune=pentium4)
	modified in Makefile.cpu

the third run actually produced a memory oops in the mem_load section, 
probably revealing some code in the VM system that didn't make it 
through the compiler in one piece. All I can say is I will probably be 
easing my *system* CFLAGS as a result of this test :).

The 486 target is used over 386 because I believe the SMP configuration 
matches higher targets more closely, as I had Hyperthreading enabled on 
all tests. Maybee I'll test that later.

All times are cumulative, using contest 0.61.

-- 
Please don't CC messages to me from mailing lists.
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no_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	269	195.5	0.0	0.0	1.00
2.6.18-gentoo-p4        3	268	195.1	0.0	0.0	1.00
2.6.18-gentoo-p4+       3	268	195.9	0.0	0.0	1.00

cacherun:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	264	199.2	0.0	0.0	0.98
2.6.18-gentoo-p4        3	263	199.2	0.0	0.0	0.98
2.6.18-gentoo-p4+       3	263	199.6	0.0	0.0	0.98

process_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	569	101.8	644.7	96.8	2.12
2.6.18-gentoo-p4        3	568	102.6	658.0	95.6	2.12
2.6.18-gentoo-p4+       3	560	102.7	661.7	95.5	2.09

ctar_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	325	166.5	11.7	16.3	1.21
2.6.18-gentoo-p4        3	321	167.3	11.3	15.3	1.20
2.6.18-gentoo-p4+       3	323	167.2	11.3	15.8	1.21

xtar_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	317	166.9	5.3	7.6	1.18
2.6.18-gentoo-p4        3	318	166.0	5.3	7.5	1.19
2.6.18-gentoo-p4+       3	320	165.0	5.3	7.5	1.19

io_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	373	137.8	79.5	18.0	1.39
2.6.18-gentoo-p4        3	378	135.4	80.6	17.4	1.41
2.6.18-gentoo-p4+       3	368	139.9	76.0	16.8	1.37

io_other:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	415	124.1	126.2	24.6	1.54
2.6.18-gentoo-p4        3	422	121.6	127.6	23.2	1.57
2.6.18-gentoo-p4+       3	426	121.1	128.7	23.2	1.59

read_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	314	169.7	15.7	3.5	1.17
2.6.18-gentoo-p4        3	311	171.4	15.3	3.2	1.16
2.6.18-gentoo-p4+       3	311	171.1	15.2	3.2	1.16

list_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	314	168.8	0.0	18.8	1.17
2.6.18-gentoo-p4        3	311	169.8	0.0	17.7	1.16
2.6.18-gentoo-p4+       3	311	169.5	0.0	18.0	1.16

mem_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	759	69.3	138.0	1.2	2.82
2.6.18-gentoo-p4        3	629	85.2	132.7	1.3	2.35
2.6.18-gentoo-p4+       3	765	68.4	142.0	1.2	2.85

dbench_load:
Kernel             [runs]	Time	CPU%	Loads	LCPU%	Ratio
2.6.18-gentoo-i486      3	616	84.4	9.7	84.7	2.29
2.6.18-gentoo-p4        3	563	92.5	8.7	79.9	2.10
2.6.18-gentoo-p4+       3	559	93.2	8.7	80.7	2.09