Re: [PATCH] O6int for interactivity

Mike Galbraith
2003-07-18T10:02:02Z

At 04:34 PM 7/18/2003 +1000, Nick Piggin wrote:

>Mike Galbraith wrote:
>
>>no_load:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 153 94.8 0.0 0.0 1.00
>>2.5.70 1 153 94.1 0.0 0.0 1.00
>>2.6.0-test1 1 153 94.1 0.0 0.0 1.00
>>2.6.0-test1-mm1 1 152 94.7 0.0 0.0 1.00
>>cacherun:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 146 98.6 0.0 0.0 0.95
>>2.5.70 1 146 98.6 0.0 0.0 0.95
>>2.6.0-test1 1 146 98.6 0.0 0.0 0.95
>>2.6.0-test1-mm1 1 146 98.6 0.0 0.0 0.96
>>process_load:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 331 43.8 90.0 55.3 2.16
>>2.5.70 1 199 72.4 27.0 25.5 1.30
>>2.6.0-test1 1 264 54.5 61.0 44.3 1.73
>>2.6.0-test1-mm1 1 323 44.9 88.0 54.2 2.12
>>ctar_load:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 190 77.9 0.0 0.0 1.24
>>2.5.70 1 186 80.1 0.0 0.0 1.22
>>2.6.0-test1 1 213 70.4 0.0 0.0 1.39
>>2.6.0-test1-mm1 1 207 72.5 0.0 0.0 1.36
>>xtar_load:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 196 75.0 0.0 3.1 1.28
>>2.5.70 1 195 75.9 0.0 3.1 1.27
>>2.6.0-test1 1 193 76.7 1.0 4.1 1.26
>>2.6.0-test1-mm1 1 195 75.9 1.0 4.1 1.28
>>io_load:
>>Kernel [runs] Time CPU% Loads LCPU% Ratio
>>2.5.69 1 437 34.6 69.1 15.1 2.86
>>2.5.70 1 401 37.7 72.3 17.4 2.62
>>2.6.0-test1 1 243 61.3 48.1 17.3 1.59
>>2.6.0-test1-mm1 1 336 44.9 64.5 17.3 2.21
>
>Looks like gcc is getting less priority after a read completes.
>Keep an eye on this please.

That _might_ (add salt) be priorities of kernel threads dropping too low.

I'm also seeing occasional total stalls under heavy I/O in the order of
10-12 seconds (even the disk stops). I have no idea if that's something in
mm or the scheduler changes though, as I've yet to do any isolation and/or
tinkering. All I know at this point is that I haven't seen it in stock yet.

-Mike