lkml.org 
[lkml]   [2010]   [Jul]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [PATCH 10/11] oom: give the dying task a higher priority
    On Wed, 30 Jun 2010 18:33:23 +0900 (JST)
    KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:

    > +static void boost_dying_task_prio(struct task_struct *p,
    > + struct mem_cgroup *mem)
    > +{
    > + struct sched_param param = { .sched_priority = 1 };
    > +
    > + if (mem)
    > + return;
    > +
    > + if (!rt_task(p))
    > + sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
    > +}

    We can actually make `param' static here. That saves a teeny bit of
    code and a little bit of stack. The oom-killer can be called when
    we're using a lot of stack.

    But if we make that change we really should make the param arg to
    sched_setscheduler_nocheck() be const. I did that (and was able to
    convert lots of callers to use a static `param') but to complete the
    job we'd need to chase through all the security goop, fixing up
    security_task_setscheduler() and callees, and I got bored.


    include/linux/sched.h | 2 +-
    kernel/kthread.c | 2 +-
    kernel/sched.c | 4 ++--
    kernel/softirq.c | 4 +++-
    kernel/stop_machine.c | 2 +-
    kernel/workqueue.c | 2 +-
    6 files changed, 9 insertions(+), 7 deletions(-)

    diff -puN kernel/kthread.c~a kernel/kthread.c
    --- a/kernel/kthread.c~a
    +++ a/kernel/kthread.c
    @@ -131,7 +131,7 @@ struct task_struct *kthread_create(int (
    wait_for_completion(&create.done);

    if (!IS_ERR(create.result)) {
    - struct sched_param param = { .sched_priority = 0 };
    + static struct sched_param param = { .sched_priority = 0 };
    va_list args;

    va_start(args, namefmt);
    diff -puN kernel/workqueue.c~a kernel/workqueue.c
    --- a/kernel/workqueue.c~a
    +++ a/kernel/workqueue.c
    @@ -962,7 +962,7 @@ init_cpu_workqueue(struct workqueue_stru

    static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
    {
    - struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
    + static struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
    struct workqueue_struct *wq = cwq->wq;
    const char *fmt = is_wq_single_threaded(wq) ? "%s" : "%s/%d";
    struct task_struct *p;
    diff -puN kernel/stop_machine.c~a kernel/stop_machine.c
    --- a/kernel/stop_machine.c~a
    +++ a/kernel/stop_machine.c
    @@ -291,7 +291,7 @@ repeat:
    static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
    unsigned long action, void *hcpu)
    {
    - struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
    + static struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
    unsigned int cpu = (unsigned long)hcpu;
    struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
    struct task_struct *p;
    diff -puN kernel/sched.c~a kernel/sched.c
    --- a/kernel/sched.c~a
    +++ a/kernel/sched.c
    @@ -4570,7 +4570,7 @@ static bool check_same_owner(struct task
    }

    static int __sched_setscheduler(struct task_struct *p, int policy,
    - struct sched_param *param, bool user)
    + const struct sched_param *param, bool user)
    {
    int retval, oldprio, oldpolicy = -1, on_rq, running;
    unsigned long flags;
    @@ -4734,7 +4734,7 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
    * but our caller might not have that capability.
    */
    int sched_setscheduler_nocheck(struct task_struct *p, int policy,
    - struct sched_param *param)
    + const struct sched_param *param)
    {
    return __sched_setscheduler(p, policy, param, false);
    }
    diff -puN kernel/softirq.c~a kernel/softirq.c
    --- a/kernel/softirq.c~a
    +++ a/kernel/softirq.c
    @@ -827,7 +827,9 @@ static int __cpuinit cpu_callback(struct
    cpumask_any(cpu_online_mask));
    case CPU_DEAD:
    case CPU_DEAD_FROZEN: {
    - struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
    + static struct sched_param param = {
    + .sched_priority = MAX_RT_PRIO-1,
    + };

    p = per_cpu(ksoftirqd, hotcpu);
    per_cpu(ksoftirqd, hotcpu) = NULL;
    diff -puN include/linux/sched.h~a include/linux/sched.h
    --- a/include/linux/sched.h~a
    +++ a/include/linux/sched.h
    @@ -1924,7 +1924,7 @@ extern int task_curr(const struct task_s
    extern int idle_cpu(int cpu);
    extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
    extern int sched_setscheduler_nocheck(struct task_struct *, int,
    - struct sched_param *);
    + const struct sched_param *);
    extern struct task_struct *idle_task(int cpu);
    extern struct task_struct *curr_task(int cpu);
    extern void set_curr_task(int cpu, struct task_struct *p);
    _


    \
     
     \ /
      Last update: 2010-07-02 23:53    [W:2.585 / U:0.508 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site