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    • /[pkg-src]/trunk/kernel26-magellan/patches-2.6.21-r4/0008-2.6.21-sched-ck-add-above-background-load-function.patch

    Contents of /trunk/kernel26-magellan/patches-2.6.21-r4/0008-2.6.21-sched-ck-add-above-background-load-function.patch

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    Revision 222 - (show annotations) (download)
    Tue Jun 12 08:03:28 2007 UTC (16 years, 10 months ago) by niro
    File size: 2992 byte(s) 
    files for 2.6.21-magellan-r4
    1 From: Con Kolivas <kernel@kolivas.org>
    2
    3 Add an above_background_load() function which can be used by other
    4 subsystems to detect if there is anything besides niced tasks running.
    5 Place it in sched.h to allow it to be compiled out if not used.
    6
    7 This version relies on DEFAULT_WEIGHT being scaled via the SD cpu scheduler
    8 with SCHED_IDLEPRIO support.
    9
    10 Signed-off-by: Con Kolivas <kernel@kolivas.org>
    11 Acked-by: Ingo Molnar <mingo@elte.hu>
    12 Cc: Peter Williams <pwil3058@bigpond.net.au>
    13 Signed-off-by: Andrew Morton <akpm@osdl.org>
    14 ---
    15
    16 include/linux/sched.h | 2 +-
    17 kernel/sched.c | 46 +++++++++++++++++++++++++++++++++++++---------
    18 2 files changed, 38 insertions(+), 10 deletions(-)
    19
    20 Index: linux-2.6.21-ck2/include/linux/sched.h
    21 ===================================================================
    22 --- linux-2.6.21-ck2.orig/include/linux/sched.h 2007-05-14 19:30:31.000000000 +1000
    23 +++ linux-2.6.21-ck2/include/linux/sched.h 2007-05-14 19:31:55.000000000 +1000
    24 @@ -133,7 +133,7 @@ extern unsigned long nr_uninterruptible(
    25 extern unsigned long nr_active(void);
    26 extern unsigned long nr_iowait(void);
    27 extern unsigned long weighted_cpuload(const int cpu);
    28 -
    29 +extern int above_background_load(void);
    30
    31 /*
    32 * Task state bitmask. NOTE! These bits are also
    33 Index: linux-2.6.21-ck2/kernel/sched.c
    34 ===================================================================
    35 --- linux-2.6.21-ck2.orig/kernel/sched.c 2007-05-14 19:31:42.000000000 +1000
    36 +++ linux-2.6.21-ck2/kernel/sched.c 2007-05-14 19:49:51.000000000 +1000
    37 @@ -1082,6 +1082,37 @@ static int effective_prio(struct task_st
    38 return p->prio;
    39 }
    40
    41 +static inline unsigned int nice_quota_ms(int nice)
    42 +{
    43 + unsigned int rr = rr_interval;
    44 +
    45 + if (nice < -6) {
    46 + rr *= nice * nice;
    47 + rr /= 40;
    48 + } else if (nice > 0)
    49 + rr = rr / 2 ? : 1;
    50 + return rr;
    51 +}
    52 +
    53 +#define DEFAULT_WEIGHT (nice_quota_ms(0) * 20 * PRIO_RANGE)
    54 +
    55 +/*
    56 + * A runqueue laden with a single nice 0 task scores a weighted_cpuload of
    57 + * SCHED_LOAD_SCALE. This function returns 1 if any cpu is laden with a
    58 + * task of nice 0 or enough lower priority tasks to bring up the
    59 + * weighted_cpuload
    60 + */
    61 +int above_background_load(void)
    62 +{
    63 + unsigned long cpu;
    64 +
    65 + for_each_online_cpu(cpu) {
    66 + if (weighted_cpuload(cpu) >= DEFAULT_WEIGHT)
    67 + return 1;
    68 + }
    69 + return 0;
    70 +}
    71 +
    72 /*
    73 * All tasks have quotas based on rr_interval. RT tasks all get rr_interval.
    74 * From nice 1 to 19 they are smaller than it only if they are at least one
    75 @@ -1092,16 +1123,13 @@ static int effective_prio(struct task_st
    76 */
    77 static inline unsigned int rr_quota(struct task_struct *p)
    78 {
    79 - int nice = TASK_NICE(p), rr = rr_interval;
    80 + unsigned int quota;
    81
    82 - if (!rt_task(p)) {
    83 - if (nice < -6) {
    84 - rr *= nice * nice;
    85 - rr /= 40;
    86 - } else if (nice > 0)
    87 - rr = rr / 2 ? : 1;
    88 - }
    89 - return MS_TO_US(rr);
    90 + if (rt_task(p))
    91 + quota = rr_interval;
    92 + else
    93 + quota = nice_quota_ms(TASK_NICE(p));
    94 + return MS_TO_US(quota);
    95 }
    96
    97 /* Every time we set the quota we need to set the load weight */