lkml.org 
[lkml]   [2003]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [PATCH] O3int interactivity for 2.5.74-mm2
    Date
    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;
    \
     
     \ /
      Last update: 2005-03-22 13:46    [W:2.146 / U:0.124 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site