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    Annotation of /trunk/kernel26-alx/patches-2.6.20-r5/0018-2.6.20-mm-kswapd_inherit_prio-1.patch

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    Revision 199 - (hide annotations) (download)
    Fri May 18 11:04:36 2007 UTC (17 years ago) by niro
    File size: 3939 byte(s) 
    -import
    1 niro 199 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     }