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My end user testing of 2.4.8-ish kernels

DISCUSSION J Sloan 2 participants 3 messages Jan 13, 2002

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J Sloan

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I did some testing today on the mini-low-latency patch.

I must admit that I was totally biased towards it from the start.

While it certainly didn't hurt anything, the bottom line is that after hours of mp3/dbench tests, I was unable to quantify any real difference between 2.4.18-pre3 vanilla and with mini low latency. They exhibit pretty much the same behaviour in terms of how much dbench it takes to start hearing audio dropouts in xmms - they were both smooth up to dbench 40, but started exhibiting sporadic audio dropouts at dbench 64.

Out of curiosity I booted up 2.4.18pre2-aa2 and found it a real gem. To my pleasant suprise I was able to run dbench 128 without hearing a _single_ audio dropout. (the dbench 128 result was 19.75 MB/sec)

With dbench 192 I did start to hear some occasional dropouts, but they were generally short, e.g. 100ms or so.

In any event, all the 2.4.18-pre-ish kernels I tested today are much better at this than e.g. 2.4.7 - at least on my hardware, I am now getting excellent interactive performance under load without preempt or low-latency patches, and that's a good thing.

IMHO the -aa kernel seems to the clear winner here -

Good for server use, good for desktop use...

Regards

jjs

#1 lore raw
Quoted 5 lines · J Sloan

I did some testing today on the mini-low-latency patch.

I must admit that I was totally biased towards it from the start.

Quoted 7 lines

While it certainly didn't hurt anything, the bottom line is that after hours of mp3/dbench tests, I was unable to quantify any real difference between 2.4.18-pre3 vanilla and with mini low latency. They exhibit pretty much the same behaviour in terms of how much dbench it takes to start hearing audio dropouts in xmms - they were both smooth up to dbench 40, but started exhibiting sporadic audio dropouts at dbench 64.

Oh well. I must have missed one.

Quoted 7 lines

Out of curiosity I booted up 2.4.18pre2-aa2 and found it a real gem. To my pleasant suprise I was able to run dbench 128 without hearing a _single_ audio dropout. (the dbench 128 result was 19.75 MB/sec)

With dbench 192 I did start to hear some occasional dropouts, but they were generally short, e.g. 100ms or so.

Quoted 7 lines

In any event, all the 2.4.18-pre-ish kernels I tested today are much better at this than e.g. 2.4.7 - at least on my hardware, I am now getting excellent interactive performance under load without preempt or low-latency patches, and that's a good thing.

IMHO the -aa kernel seems to the clear winner here -

the -aa kernel basically includes everything that's in the mini-ll patch. If you merge -aa, you get mini-ll. Plus the one I missed :)

-

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In reply to J Sloan
Quoted 2 lines · Andrew Morton

the -aa kernel basically includes everything that's in the mini-ll patch. If you merge -aa, you get mini-ll. Plus the one I missed :)

Ah, that explains a lot -

OK, things are making more sense now...

I look forward to mini-ll and the other tweaks
going into the mainstream kernel!

cu

jjs