Re: [patch] TASK_NONINTERACTIVE (was: Machine Freezes while Running Crossover Office)

Gene Heskett
2005-06-01T18:55:23Z

On Wednesday 01 June 2005 03:35, Ingo Molnar wrote:
>Pekka, could you check whether the patch below solves your Wine
> problem (without hurting interactivity otherwise)?
>
> Ingo
>
>----
>
>this patch implements a task state bit (TASK_NONINTERACTIVE), which
> can be used by blocking points to mark the task's wait as
> "non-interactive". This does not mean the task will be considered a
> CPU-hog - the wait will simply not have an effect on the waiting
> task's priority - positive or negative alike. Right now only
> pipe_wait() will make use of it, because it's a common source of
> not-so-interactive waits (kernel compilation jobs, etc.).
>
>Signed-off-by: Ingo Molnar <mingo@elte.hu>
>
>--- linux/fs/pipe.c.orig
>+++ linux/fs/pipe.c
>@@ -39,7 +39,11 @@ void pipe_wait(struct inode * inode)
> {
> DEFINE_WAIT(wait);
>
>- prepare_to_wait(PIPE_WAIT(*inode), &wait, TASK_INTERRUPTIBLE);
>+ /*
>+ * Pipes are system-local resources, so sleeping on them
>+ * is considered a noninteractive wait:
>+ */
>+ prepare_to_wait(PIPE_WAIT(*inode), &wait,
> TASK_INTERRUPTIBLE|TASK_NONINTERACTIVE); up(PIPE_SEM(*inode));
> schedule();
> finish_wait(PIPE_WAIT(*inode), &wait);
>--- linux/kernel/sched.c.orig
>+++ linux/kernel/sched.c
>@@ -1085,6 +1085,16 @@ out_activate:
> }
>
> /*
>+ * Tasks that have marked their sleep as noninteractive get
>+ * woken up without updating their sleep average. (i.e. their
>+ * sleep is handled in a priority-neutral manner, no priority
>+ * boost and no penalty.)
>+ */
>+ if (old_state & TASK_NONINTERACTIVE)
>+ __activate_task(p, rq);
>+ else
>+ activate_task(p, rq, cpu == this_cpu);
>+ /*
> * Sync wakeups (i.e. those types of wakeups where the waker
> * has indicated that it will leave the CPU in short order)
> * don't trigger a preemption, if the woken up task will run on
>@@ -1092,7 +1102,6 @@ out_activate:
> * the waker guarantees that the freshly woken up task is going
> * to be considered on this CPU.)
> */
>- activate_task(p, rq, cpu == this_cpu);
> if (!sync || cpu != this_cpu) {
> if (TASK_PREEMPTS_CURR(p, rq))
> resched_task(rq->curr);
>--- linux/include/linux/sched.h.orig
>+++ linux/include/linux/sched.h
>@@ -112,6 +112,7 @@ extern unsigned long nr_iowait(void);
> #define TASK_TRACED 8
> #define EXIT_ZOMBIE 16
> #define EXIT_DEAD 32
>+#define TASK_NONINTERACTIVE 64

This define (64) is already used in the rc5-git5 patch, but with
another name, so it fails during the patching...

How can we sort this?

> #define __set_task_state(tsk, state_value) \
> do { (tsk)->state = (state_value); } while (0)
>-
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--
Cheers, Gene
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