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Annotation of /trunk/kernel26-magellan/patches-2.6.16-r12/0002-2.6.16-sched-smpnice-apply-review-suggestions.patch
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Revision 72 -
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Mon Jun 5 09:25:38 2006 UTC (17 years, 11 months ago) by niro
File size: 4150 byte(s)
Mon Jun 5 09:25:38 2006 UTC (17 years, 11 months ago) by niro
File size: 4150 byte(s)
ver bump to 2.6.16-r12: - updated to linux-2.6.16.19 - updated to ck11
| 1 | niro | 72 | |
| 2 | From: Peter Williams <pwil3058@bigpond.net.au> | ||
| 3 | |||
| 4 | This patch applies the suggestions made by Con Kolivas for improving the | ||
| 5 | smpnice code. | ||
| 6 | |||
| 7 | The non cosmetic part of the patch addresses the fact the mapping from nice | ||
| 8 | values to task load weights for negative nice values does not match the | ||
| 9 | implied CPU allocations in the function task_timeslice(). As suggested by | ||
| 10 | Con the mapping function now uses the time slice information directly (via | ||
| 11 | a slightly modified interface). | ||
| 12 | |||
| 13 | Signed-off-by: Peter Williams <pwil3058@bigpond.com.au> | ||
| 14 | Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> | ||
| 15 | Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> | ||
| 16 | Cc: Ingo Molnar <mingo@elte.hu> | ||
| 17 | Cc: Nick Piggin <nickpiggin@yahoo.com.au> | ||
| 18 | Cc: Con Kolivas <kernel@kolivas.org> | ||
| 19 | Cc: John Hawkes <hawkes@sgi.com> | ||
| 20 | Signed-off-by: Andrew Morton <akpm@osdl.org> | ||
| 21 | include/linux/sched.h | 6 +++--- | ||
| 22 | kernel/sched.c | 34 +++++++++++++++++++++------------- | ||
| 23 | 2 files changed, 24 insertions(+), 16 deletions(-) | ||
| 24 | |||
| 25 | Index: linux-2.6.16-ck1/include/linux/sched.h | ||
| 26 | =================================================================== | ||
| 27 | --- linux-2.6.16-ck1.orig/include/linux/sched.h 2006-03-20 20:46:44.000000000 +1100 | ||
| 28 | +++ linux-2.6.16-ck1/include/linux/sched.h 2006-03-20 20:46:44.000000000 +1100 | ||
| 29 | @@ -698,13 +698,13 @@ struct task_struct { | ||
| 30 | |||
| 31 | int lock_depth; /* BKL lock depth */ | ||
| 32 | |||
| 33 | -#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) | ||
| 34 | +#ifdef CONFIG_SMP | ||
| 35 | +#ifdef __ARCH_WANT_UNLOCKED_CTXSW | ||
| 36 | int oncpu; | ||
| 37 | #endif | ||
| 38 | - int prio, static_prio; | ||
| 39 | -#ifdef CONFIG_SMP | ||
| 40 | int load_weight; /* for load balancing purposes */ | ||
| 41 | #endif | ||
| 42 | + int prio, static_prio; | ||
| 43 | struct list_head run_list; | ||
| 44 | prio_array_t *array; | ||
| 45 | |||
| 46 | Index: linux-2.6.16-ck1/kernel/sched.c | ||
| 47 | =================================================================== | ||
| 48 | --- linux-2.6.16-ck1.orig/kernel/sched.c 2006-03-20 20:46:44.000000000 +1100 | ||
| 49 | +++ linux-2.6.16-ck1/kernel/sched.c 2006-03-20 20:46:44.000000000 +1100 | ||
| 50 | @@ -168,13 +168,19 @@ | ||
| 51 | #define SCALE_PRIO(x, prio) \ | ||
| 52 | max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO/2), MIN_TIMESLICE) | ||
| 53 | |||
| 54 | -static unsigned int task_timeslice(task_t *p) | ||
| 55 | +static unsigned int static_prio_timeslice(int static_prio) | ||
| 56 | { | ||
| 57 | - if (p->static_prio < NICE_TO_PRIO(0)) | ||
| 58 | - return SCALE_PRIO(DEF_TIMESLICE*4, p->static_prio); | ||
| 59 | + if (static_prio < NICE_TO_PRIO(0)) | ||
| 60 | + return SCALE_PRIO(DEF_TIMESLICE*4, static_prio); | ||
| 61 | else | ||
| 62 | - return SCALE_PRIO(DEF_TIMESLICE, p->static_prio); | ||
| 63 | + return SCALE_PRIO(DEF_TIMESLICE, static_prio); | ||
| 64 | } | ||
| 65 | + | ||
| 66 | +static inline unsigned int task_timeslice(task_t *p) | ||
| 67 | +{ | ||
| 68 | + return static_prio_timeslice(p->static_prio); | ||
| 69 | +} | ||
| 70 | + | ||
| 71 | #define task_hot(p, now, sd) ((long long) ((now) - (p)->last_ran) \ | ||
| 72 | < (long long) (sd)->cache_hot_time) | ||
| 73 | |||
| 74 | @@ -667,21 +673,23 @@ static int effective_prio(task_t *p) | ||
| 75 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | ||
| 76 | * of tasks with abnormal "nice" values across CPUs the contribution that | ||
| 77 | * each task makes to its run queue's load is weighted according to its | ||
| 78 | - * scheduling class and "nice" value. | ||
| 79 | + * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a | ||
| 80 | + * scaled version of the new time slice allocation that they receive on time | ||
| 81 | + * slice expiry etc. | ||
| 82 | */ | ||
| 83 | |||
| 84 | /* | ||
| 85 | - * Priority weight for load balancing ranges from 1/20 (nice==19) to 459/20 (RT | ||
| 86 | - * priority of 100). | ||
| 87 | + * Assume: static_prio_timeslice(NICE_TO_PRIO(0)) == DEF_TIMESLICE | ||
| 88 | + * If static_prio_timeslice() is ever changed to break this assumption then | ||
| 89 | + * this code will need modification | ||
| 90 | */ | ||
| 91 | -#define NICE_TO_LOAD_PRIO(nice) \ | ||
| 92 | - ((nice >= 0) ? (20 - (nice)) : (20 + (nice) * (nice))) | ||
| 93 | +#define TIME_SLICE_NICE_ZERO DEF_TIMESLICE | ||
| 94 | #define LOAD_WEIGHT(lp) \ | ||
| 95 | - (((lp) * SCHED_LOAD_SCALE) / NICE_TO_LOAD_PRIO(0)) | ||
| 96 | -#define NICE_TO_LOAD_WEIGHT(nice) LOAD_WEIGHT(NICE_TO_LOAD_PRIO(nice)) | ||
| 97 | -#define PRIO_TO_LOAD_WEIGHT(prio) NICE_TO_LOAD_WEIGHT(PRIO_TO_NICE(prio)) | ||
| 98 | + (((lp) * SCHED_LOAD_SCALE) / TIME_SLICE_NICE_ZERO) | ||
| 99 | +#define PRIO_TO_LOAD_WEIGHT(prio) \ | ||
| 100 | + LOAD_WEIGHT(static_prio_timeslice(prio)) | ||
| 101 | #define RTPRIO_TO_LOAD_WEIGHT(rp) \ | ||
| 102 | - LOAD_WEIGHT(NICE_TO_LOAD_PRIO(-20) + (rp)) | ||
| 103 | + (PRIO_TO_LOAD_WEIGHT(MAX_RT_PRIO) + LOAD_WEIGHT(rp)) | ||
| 104 | |||
| 105 | static inline void set_load_weight(task_t *p) | ||
| 106 | { |