Re: More vm benchmarking

Nick Piggin
2004-02-25T09:57:21Z

Andrew Morton wrote:

>Nick Piggin <piggin@cyberone.com.au> wrote:
>
>>kernel | run | -j5 | -j10 | -j15 |
>> 2.6.3 1 136 886 2511
>> 2.6.3 2 150 838 2465
>>
>> -mm2 1 136 646 1484
>> -mm2 2 142 676 1265
>>
>> -mm3 1 135 881 1828
>> -mm3 2 146 790 1844
>>
>> This quite clearly shows your patches hurting as I told you.
>>
>
>Probably. But these differences are small, relative to some differences
>wrt 2.4.x
>
>

2.4 should be pretty close to -mm2 for -j10 and hopefully a
bit worse at -j15. That is what previous benchmarks have been
showing anyway. I better get some 2.4 numbers.

Either way, they're not that small.

>>Why did it get slower?
>>
>
>Dunno. Maybe the workload prefers imbalanced zone scanning.
>
>

Seriously? I find that a bit hard to swallow. Especially
considering I wouldn't have anything that uses ZONE_DMA
on this system.

>>I assume it is because the batching patch places uneven
>> pressure on normal and DMA zones.
>>
>
>The patch improves highmem-vs-lowmem balancing from 10:1 to 1:1. What
>makes you think that it worsens ZONE_NORMAL-vs-ZONE_DMA balancing?
>
>It's easy enough to instrument - just split pgsteal_lo into pgsteal_normal
>and pgsteal_dma.
>
>

Sure that can tell you if something is really wrong, but it
is pretty hard to read much from that.

Anyway I don't have code or numbers right now so that means
I have to shut up ;)