Messages in this thread |  | | | From | Roger Larsson <> | | Subject | Re: Feedback on preemptible kernel patch | | Date | Tue, 18 Sep 2001 20:18:10 +0200 |
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On Tuesday den 18 September 2001 06:06, Dieter Nützel wrote: > Yes, but no crash or oops for me. > "Only" some "stalls" during MPEG/Ogg-Vorbis playback (2-5 sec) :-(
> > > But I get some hiccup during noatun (mp3, ogg, etc. player for KDE-2.2) > > > or plaympeg together with dbench (16, 32). ReiserFS needs some > > > preemption fixes, too? > > > > You may still get some small hiccups ( < 1 second?) even with the > > preemption patch, as kernel locks prevent preemption (the patch can't > > guarentee low latency, just preemption outside of the locks). > > Sadly 2-5 seconds at the beginning of dbench and during bonnie++ block > operations (huge IO pressure, ~20% system, 3-5% user, 116308 kilobytes > paged out). > > > However, how bad was the hiccups with preemption disabled? I have heard > > reports where it is 3-5sec at times. > > Yes, nearly the same. >
Do you run with the playback process reniced -N? It should really run with a low SCHED_FIFO or SCHED_RT policy. But renicing it with a negative value gives some of the benefits... (but you need to run as root) In addition to this the program might need to lock its pages down - the only thing I can think of that could cause several seconds delay would be if it has been swapped out...
/RogerL
-- Roger Larsson Skellefteå Sweden - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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