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    Contents of /trunk/kernel26-magellan/patches-2.6.20-r4/0018-2.6.20-mm-kswapd_inherit_prio-1.patch

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    Revision 132 - (show annotations) (download)
    Fri Apr 27 15:24:56 2007 UTC (17 years ago) by niro
    File size: 3939 byte(s) 
    files for 2.6.20-r4
    1 When kswapd is awoken due to reclaim by a running task, set the priority of
    2 kswapd to that of the calling task thus making memory reclaim cpu activity
    3 affected by nice level.
    4
    5 Signed-off-by: Con Kolivas <kernel@kolivas.org>
    6
    7 include/linux/mmzone.h | 2 +-
    8 mm/page_alloc.c | 2 +-
    9 mm/vmscan.c | 41 +++++++++++++++++++++++++++++++++++++++--
    10 3 files changed, 41 insertions(+), 4 deletions(-)
    11
    12 Index: linux-2.6.20-ck1/include/linux/mmzone.h
    13 ===================================================================
    14 --- linux-2.6.20-ck1.orig/include/linux/mmzone.h 2007-02-16 19:01:33.000000000 +1100
    15 +++ linux-2.6.20-ck1/include/linux/mmzone.h 2007-02-16 19:01:33.000000000 +1100
    16 @@ -447,7 +447,7 @@ void __get_zone_counts(unsigned long *ac
    17 void get_zone_counts(unsigned long *active, unsigned long *inactive,
    18 unsigned long *free);
    19 void build_all_zonelists(void);
    20 -void wakeup_kswapd(struct zone *zone, int order);
    21 +void wakeup_kswapd(struct zone *zone, int order, struct task_struct *p);
    22 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
    23 int classzone_idx, int alloc_flags);
    24 enum memmap_context {
    25 Index: linux-2.6.20-ck1/mm/page_alloc.c
    26 ===================================================================
    27 --- linux-2.6.20-ck1.orig/mm/page_alloc.c 2007-02-16 19:01:33.000000000 +1100
    28 +++ linux-2.6.20-ck1/mm/page_alloc.c 2007-02-16 19:01:33.000000000 +1100
    29 @@ -1252,7 +1252,7 @@ restart:
    30 goto nopage;
    31
    32 for (z = zonelist->zones; *z; z++)
    33 - wakeup_kswapd(*z, order);
    34 + wakeup_kswapd(*z, order, p);
    35
    36 /*
    37 * OK, we're below the kswapd watermark and have kicked background
    38 Index: linux-2.6.20-ck1/mm/vmscan.c
    39 ===================================================================
    40 --- linux-2.6.20-ck1.orig/mm/vmscan.c 2007-02-16 19:01:33.000000000 +1100
    41 +++ linux-2.6.20-ck1/mm/vmscan.c 2007-02-16 19:01:33.000000000 +1100
    42 @@ -963,6 +963,39 @@ static unsigned long shrink_zone(int pri
    43 }
    44
    45 /*
    46 + * Helper functions to adjust nice level of kswapd, based on the priority of
    47 + * the task (p) that called it. If it is already higher priority we do not
    48 + * demote its nice level since it is still working on behalf of a higher
    49 + * priority task. With kernel threads we leave it at nice 0.
    50 + *
    51 + * We don't ever run kswapd real time, so if a real time task calls kswapd we
    52 + * set it to highest SCHED_NORMAL priority.
    53 + */
    54 +static int effective_sc_prio(struct task_struct *p)
    55 +{
    56 + if (likely(p->mm)) {
    57 + if (rt_task(p))
    58 + return -20;
    59 + return task_nice(p);
    60 + }
    61 + return 0;
    62 +}
    63 +
    64 +static void set_kswapd_nice(struct task_struct *kswapd, struct task_struct *p,
    65 + int active)
    66 +{
    67 + long nice = effective_sc_prio(p);
    68 +
    69 + if (task_nice(kswapd) > nice || !active)
    70 + set_user_nice(kswapd, nice);
    71 +}
    72 +
    73 +static int sc_priority(struct task_struct *p)
    74 +{
    75 + return (DEF_PRIORITY + (DEF_PRIORITY * effective_sc_prio(p) / 40));
    76 +}
    77 +
    78 +/*
    79 * This is the direct reclaim path, for page-allocating processes. We only
    80 * try to reclaim pages from zones which will satisfy the caller's allocation
    81 * request.
    82 @@ -1349,6 +1382,7 @@ static int kswapd(void *p)
    83 */
    84 order = new_order;
    85 } else {
    86 + set_user_nice(tsk, 0);
    87 schedule();
    88 order = pgdat->kswapd_max_order;
    89 }
    90 @@ -1362,9 +1396,10 @@ static int kswapd(void *p)
    91 /*
    92 * A zone is low on free memory, so wake its kswapd task to service it.
    93 */
    94 -void wakeup_kswapd(struct zone *zone, int order)
    95 +void wakeup_kswapd(struct zone *zone, int order, struct task_struct *p)
    96 {
    97 pg_data_t *pgdat;
    98 + int active;
    99
    100 if (!populated_zone(zone))
    101 return;
    102 @@ -1376,7 +1411,9 @@ void wakeup_kswapd(struct zone *zone, in
    103 pgdat->kswapd_max_order = order;
    104 if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
    105 return;
    106 - if (!waitqueue_active(&pgdat->kswapd_wait))
    107 + active = waitqueue_active(&pgdat->kswapd_wait);
    108 + set_kswapd_nice(pgdat->kswapd, p, active);
    109 + if (!active)
    110 return;
    111 wake_up_interruptible(&pgdat->kswapd_wait);
    112 }