[patch 12/27] set TASK_RUNNING in cond_resched()

Andrew Morton (akpm@zip.com.au)
Thu, 04 Jul 2002 16:54:26 -0700


do_select() does set_current_state(TASK_INTERRUPTIBLE) then calls
__pollwait() which calls __get_free_page() and the cond_resched() which
I added to the pagecache reclaim code never returns.

The patch makes cond_resched() more useful by setting current->state to
TASK_RUNNING before scheduling.

include/linux/sched.h | 3 ++-
kernel/ksyms.c | 1 +
kernel/sched.c | 6 ++++++
3 files changed, 9 insertions(+), 1 deletion(-)

--- 2.5.24/include/linux/sched.h~cond_resched-fix Thu Jul 4 16:17:17 2002
+++ 2.5.24-akpm/include/linux/sched.h Thu Jul 4 16:22:11 2002
@@ -837,10 +837,11 @@ static inline int need_resched(void)
return unlikely(test_thread_flag(TIF_NEED_RESCHED));
}

+extern void __cond_resched(void);
static inline void cond_resched(void)
{
if (need_resched())
- schedule();
+ __cond_resched();
}

/* Reevaluate whether the task has signals pending delivery.
--- 2.5.24/kernel/sched.c~cond_resched-fix Thu Jul 4 16:17:17 2002
+++ 2.5.24-akpm/kernel/sched.c Thu Jul 4 16:22:11 2002
@@ -1447,6 +1447,12 @@ asmlinkage long sys_sched_yield(void)
return 0;
}

+void __cond_resched(void)
+{
+ set_current_state(TASK_RUNNING);
+ schedule();
+}
+
asmlinkage long sys_sched_get_priority_max(int policy)
{
int ret = -EINVAL;
--- 2.5.24/kernel/ksyms.c~cond_resched-fix Thu Jul 4 16:17:17 2002
+++ 2.5.24-akpm/kernel/ksyms.c Thu Jul 4 16:22:11 2002
@@ -473,6 +473,7 @@ EXPORT_SYMBOL(preempt_schedule);
#endif
EXPORT_SYMBOL(schedule_timeout);
EXPORT_SYMBOL(sys_sched_yield);
+EXPORT_SYMBOL(__cond_resched);
EXPORT_SYMBOL(set_user_nice);
EXPORT_SYMBOL(task_nice);
EXPORT_SYMBOL_GPL(idle_cpu);

-
-
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