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Commit 5e686019 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'sched-fixes-for-linus' of... 

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, tsc, sched: Recompute cyc2ns_offset's during resume from sleep states
  sched: Fix rq->clock synchronization when migrating tasks
parents e09b4e9a cd7240c0

arch/x86/include/asm/tsc.h

+2 −0
Original line number Diff line number Diff line
@@ -59,5 +59,7 @@ extern void check_tsc_sync_source(int cpu); 
extern void check_tsc_sync_target(void);



extern int notsc_setup(char *);

extern void save_sched_clock_state(void);

extern void restore_sched_clock_state(void);



#endif /* _ASM_X86_TSC_H */

arch/x86/kernel/tsc.c

+38 −0
Original line number Diff line number Diff line
@@ -626,6 +626,44 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu) 
	local_irq_restore(flags);

}



static unsigned long long cyc2ns_suspend;



void save_sched_clock_state(void)

{

	if (!sched_clock_stable)

		return;



	cyc2ns_suspend = sched_clock();

}



/*

 * Even on processors with invariant TSC, TSC gets reset in some the

 * ACPI system sleep states. And in some systems BIOS seem to reinit TSC to

 * arbitrary value (still sync'd across cpu's) during resume from such sleep

 * states. To cope up with this, recompute the cyc2ns_offset for each cpu so

 * that sched_clock() continues from the point where it was left off during

 * suspend.

 */

void restore_sched_clock_state(void)

{

	unsigned long long offset;

	unsigned long flags;

	int cpu;



	if (!sched_clock_stable)

		return;



	local_irq_save(flags);



	get_cpu_var(cyc2ns_offset) = 0;

	offset = cyc2ns_suspend - sched_clock();



	for_each_possible_cpu(cpu)

		per_cpu(cyc2ns_offset, cpu) = offset;



	local_irq_restore(flags);

}



#ifdef CONFIG_CPU_FREQ



/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency

arch/x86/power/cpu.c

+2 −0
Original line number Diff line number Diff line
@@ -113,6 +113,7 @@ static void __save_processor_state(struct saved_context *ctxt) 
void save_processor_state(void)

{

	__save_processor_state(&saved_context);

	save_sched_clock_state();

}

#ifdef CONFIG_X86_32

EXPORT_SYMBOL(save_processor_state);
@@ -229,6 +230,7 @@ static void __restore_processor_state(struct saved_context *ctxt) 
void restore_processor_state(void)

{

	__restore_processor_state(&saved_context);

	restore_sched_clock_state();

}

#ifdef CONFIG_X86_32

EXPORT_SYMBOL(restore_processor_state);

kernel/sched_fair.c

+2 −0
Original line number Diff line number Diff line
@@ -3752,6 +3752,8 @@ static void task_fork_fair(struct task_struct *p) 


	raw_spin_lock_irqsave(&rq->lock, flags);



	update_rq_clock(rq);



	if (unlikely(task_cpu(p) != this_cpu))

		__set_task_cpu(p, this_cpu);