Messages in this thread Patch in this message | | | Date | Sun, 21 Dec 2003 02:20:31 +1100 | From | Nick Piggin <> | Subject | [PATCH 2/5] 2.6.0 sched fork cleanup |
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Move some fork related scheduler policy from fork.c to sched.c where it belongs.
Move some fork related scheduler policy from fork.c to sched.c where it belongs.
linux-2.6-npiggin/include/linux/sched.h | 1 linux-2.6-npiggin/kernel/fork.c | 30 ++------------------------- linux-2.6-npiggin/kernel/sched.c | 35 ++++++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 27 deletions(-)
diff -puN include/linux/sched.h~sched-fork-cleanup include/linux/sched.h --- linux-2.6/include/linux/sched.h~sched-fork-cleanup 2003-12-19 14:22:29.000000000 +1100 +++ linux-2.6-npiggin/include/linux/sched.h 2003-12-19 14:22:29.000000000 +1100 @@ -580,6 +580,7 @@ extern int FASTCALL(wake_up_process(stru static inline void kick_process(struct task_struct *tsk) { } #endif extern void FASTCALL(wake_up_forked_process(struct task_struct * tsk)); +extern void FASTCALL(sched_fork(task_t * p)); extern void FASTCALL(sched_exit(task_t * p)); asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru); diff -puN kernel/fork.c~sched-fork-cleanup kernel/fork.c --- linux-2.6/kernel/fork.c~sched-fork-cleanup 2003-12-19 14:22:29.000000000 +1100 +++ linux-2.6-npiggin/kernel/fork.c 2003-12-19 14:22:29.000000000 +1100 @@ -973,33 +973,9 @@ struct task_struct *copy_process(unsigne p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL); p->pdeath_signal = 0; - /* - * Share the timeslice between parent and child, thus the - * total amount of pending timeslices in the system doesn't change, - * resulting in more scheduling fairness. - */ - local_irq_disable(); - p->time_slice = (current->time_slice + 1) >> 1; - /* - * The remainder of the first timeslice might be recovered by - * the parent if the child exits early enough. - */ - p->first_time_slice = 1; - current->time_slice >>= 1; - p->timestamp = sched_clock(); - if (!current->time_slice) { - /* - * This case is rare, it happens when the parent has only - * a single jiffy left from its timeslice. Taking the - * runqueue lock is not a problem. - */ - current->time_slice = 1; - preempt_disable(); - scheduler_tick(0, 0); - local_irq_enable(); - preempt_enable(); - } else - local_irq_enable(); + /* Perform scheduler related accounting */ + sched_fork(p); + /* * Ok, add it to the run-queues and make it * visible to the rest of the system. diff -puN kernel/sched.c~sched-fork-cleanup kernel/sched.c --- linux-2.6/kernel/sched.c~sched-fork-cleanup 2003-12-19 14:22:29.000000000 +1100 +++ linux-2.6-npiggin/kernel/sched.c 2003-12-19 14:22:29.000000000 +1100 @@ -674,6 +674,41 @@ int wake_up_state(task_t *p, unsigned in } /* + * Perform scheduler related accounting for a newly forked process p. + * p is forked by current. + */ +void sched_fork(task_t *p) +{ + /* + * Share the timeslice between parent and child, thus the + * total amount of pending timeslices in the system doesn't change, + * resulting in more scheduling fairness. + */ + local_irq_disable(); + p->time_slice = (current->time_slice + 1) >> 1; + /* + * The remainder of the first timeslice might be recovered by + * the parent if the child exits early enough. + */ + p->first_time_slice = 1; + current->time_slice >>= 1; + p->timestamp = sched_clock(); + if (!current->time_slice) { + /* + * This case is rare, it happens when the parent has only + * a single jiffy left from its timeslice. Taking the + * runqueue lock is not a problem. + */ + current->time_slice = 1; + preempt_disable(); + scheduler_tick(0, 0); + local_irq_enable(); + preempt_enable(); + } else + local_irq_enable(); +} + +/* * wake_up_forked_process - wake up a freshly forked process. * * This function will do some initial scheduler statistics housekeeping _
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