Messages in this thread Patch in this message | | | From | Con Kolivas <> | Subject | Re: [PATCH] O3int interactivity for 2.5.74-mm2 | Date | Mon, 7 Jul 2003 13:19:57 +1000 |
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On Mon, 7 Jul 2003 04:36, Felipe Alfaro Solana wrote: > On Sun, 2003-07-06 at 19:16, Con Kolivas wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Attached is an incremental patch against 2.5.74-mm2 with more > > interactivity work. Audio should be quite resistant to skips with this, > > and it should not induce further unfairness. > > > > Changes: > > The sleep_avg buffer was not needed with the improved semantics in O2int > > so it has been removed entirely as it created regressions in O2int. > > > > A small change to the idle detection code to only make tasks with enough > > accumulated sleep_avg become idle. > > > > Minor cleanups and clarified code. > > > > > > Other issues: > > Jerky mouse with heavy page rendering in web browsers remains. This is a > > different issue to the audio and will need some more thought. > > > > The patch is also available for download here: > > http://kernel.kolivas.org/2.5 > > > > Note for those who wish to get smooth X desktop feel now for their own > > use, the granularity patch on that website will do wonders on top of > > O3int, but a different approach will be needed for mainstream > > consumption. > > I'm seeing extreme X starvation with this patch under 2.5.74-mm2 when > starting a CPU hogger: > > 1. Start a KDE session. > 2. Launch a Konsole > 3. Launch Konqueror > 4. Launch XMMS > 5. Make XMMS play an MP3 file > 6. On the Konsole terminal, run "while true; do a=2; done" > > When the "while..." is run, X starves completely for ~5 seconds (e.g. > the mouse cursor doesn't respond to my input events). After those 5 > seconds, the mouse cursor goes jerky for a while (~2 seconds) and then > the system gets responsive.
Aha!
Thanks to Felipe who picked this up I was able to find the one bug causing me grief. The idle detection code was allowing the sleep_avg to get to ridiculously high levels. This is corrected in the following replacement O3int patch. Note this fixes the mozilla issue too. Kick arse!!
Con --- linux-2.5.74/kernel/sched.c 2003-07-07 02:13:57.000000000 +1000 +++ linux-2.5.74-test/kernel/sched.c 2003-07-07 13:15:04.000000000 +1000 @@ -77,6 +77,7 @@ #define MAX_SLEEP_AVG (10*HZ) #define STARVATION_LIMIT (10*HZ) #define NODE_THRESHOLD 125 +#define MAX_BONUS ((MAX_USER_PRIO - MAX_RT_PRIO) * PRIO_BONUS_RATIO / 100) /* * If a task is 'interactive' then we reinsert it in the active @@ -306,7 +307,7 @@ static inline void normalise_sleep(task_ { unsigned long old_avg_time = jiffies - p->avg_start; - if (old_avg_time < MIN_SLEEP_AVG) + if (unlikely(old_avg_time < MIN_SLEEP_AVG)) return; if (p->sleep_avg > MAX_SLEEP_AVG) @@ -406,22 +407,19 @@ static inline void activate_task(task_t */ if (runtime < MAX_SLEEP_AVG) p->sleep_avg += (runtime - p->sleep_avg) * (MAX_SLEEP_AVG - runtime) * - (10 - INTERACTIVE_DELTA) / 10 / MAX_SLEEP_AVG; + (MAX_BONUS - INTERACTIVE_DELTA) / MAX_BONUS / MAX_SLEEP_AVG; - /* - * Keep a buffer of 10% sleep_avg - * to prevent short bursts of cpu activity from making - * interactive tasks lose their bonus - */ - if (p->sleep_avg > MAX_SLEEP_AVG * 11/10) - p->sleep_avg = MAX_SLEEP_AVG * 11/10; + if (p->sleep_avg > MAX_SLEEP_AVG) + p->sleep_avg = MAX_SLEEP_AVG; /* * Tasks that sleep a long time are categorised as idle and * get their static priority only */ - if (sleep_time > MIN_SLEEP_AVG) - p->sleep_avg = runtime / 2; + if (sleep_time > MIN_SLEEP_AVG){ + p->avg_start = jiffies - MIN_SLEEP_AVG; + p->sleep_avg = MIN_SLEEP_AVG / 2; + } if (unlikely(p->avg_start > jiffies)){ p->avg_start = jiffies; | |