Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 152e9b86 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/vtime: steal time exponential moving average 



To be able to judge the current overcommitment ratio for a CPU add
a lowcore field with the exponential moving average of the steal time.
The average is updated every tick.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 01396a37

arch/s390/include/asm/lowcore.h

+31 −30
Original line number Diff line number Diff line
@@ -91,52 +91,53 @@ struct lowcore { 
	__u64	hardirq_timer;			/* 0x02e8 */

	__u64	softirq_timer;			/* 0x02f0 */

	__u64	steal_timer;			/* 0x02f8 */

	__u64	last_update_timer;		/* 0x0300 */

	__u64	last_update_clock;		/* 0x0308 */

	__u64	int_clock;			/* 0x0310 */

	__u64	mcck_clock;			/* 0x0318 */

	__u64	clock_comparator;		/* 0x0320 */

	__u64	boot_clock[2];			/* 0x0328 */

	__u64	avg_steal_timer;		/* 0x0300 */

	__u64	last_update_timer;		/* 0x0308 */

	__u64	last_update_clock;		/* 0x0310 */

	__u64	int_clock;			/* 0x0318*/

	__u64	mcck_clock;			/* 0x0320 */

	__u64	clock_comparator;		/* 0x0328 */

	__u64	boot_clock[2];			/* 0x0330 */



	/* Current process. */

	__u64	current_task;			/* 0x0338 */

	__u64	kernel_stack;			/* 0x0340 */

	__u64	current_task;			/* 0x0340 */

	__u64	kernel_stack;			/* 0x0348 */



	/* Interrupt, DAT-off and restartstack. */

	__u64	async_stack;			/* 0x0348 */

	__u64	nodat_stack;			/* 0x0350 */

	__u64	restart_stack;			/* 0x0358 */

	__u64	async_stack;			/* 0x0350 */

	__u64	nodat_stack;			/* 0x0358 */

	__u64	restart_stack;			/* 0x0360 */



	/* Restart function and parameter. */

	__u64	restart_fn;			/* 0x0360 */

	__u64	restart_data;			/* 0x0368 */

	__u64	restart_source;			/* 0x0370 */

	__u64	restart_fn;			/* 0x0368 */

	__u64	restart_data;			/* 0x0370 */

	__u64	restart_source;			/* 0x0378 */



	/* Address space pointer. */

	__u64	kernel_asce;			/* 0x0378 */

	__u64	user_asce;			/* 0x0380 */

	__u64	vdso_asce;			/* 0x0388 */

	__u64	kernel_asce;			/* 0x0380 */

	__u64	user_asce;			/* 0x0388 */

	__u64	vdso_asce;			/* 0x0390 */



	/*

	 * The lpp and current_pid fields form a

	 * 64-bit value that is set as program

	 * parameter with the LPP instruction.

	 */

	__u32	lpp;				/* 0x0390 */

	__u32	current_pid;			/* 0x0394 */

	__u32	lpp;				/* 0x0398 */

	__u32	current_pid;			/* 0x039c */



	/* SMP info area */

	__u32	cpu_nr;				/* 0x0398 */

	__u32	softirq_pending;		/* 0x039c */

	__u32	preempt_count;			/* 0x03a0 */

	__u32	spinlock_lockval;		/* 0x03a4 */

	__u32	spinlock_index;			/* 0x03a8 */

	__u32	fpu_flags;			/* 0x03ac */

	__u64	percpu_offset;			/* 0x03b0 */

	__u64	vdso_per_cpu_data;		/* 0x03b8 */

	__u64	machine_flags;			/* 0x03c0 */

	__u64	gmap;				/* 0x03c8 */

	__u8	pad_0x03d0[0x0400-0x03d0];	/* 0x03d0 */

	__u32	cpu_nr;				/* 0x03a0 */

	__u32	softirq_pending;		/* 0x03a4 */

	__u32	preempt_count;			/* 0x03a8 */

	__u32	spinlock_lockval;		/* 0x03ac */

	__u32	spinlock_index;			/* 0x03b0 */

	__u32	fpu_flags;			/* 0x03b4 */

	__u64	percpu_offset;			/* 0x03b8 */

	__u64	vdso_per_cpu_data;		/* 0x03c0 */

	__u64	machine_flags;			/* 0x03c8 */

	__u64	gmap;				/* 0x03d0 */

	__u8	pad_0x03d8[0x0400-0x03d8];	/* 0x03d8 */



	/* br %r1 trampoline */

	__u16	br_r1_trampoline;		/* 0x0400 */

arch/s390/kernel/smp.c

+2 −1
Original line number Diff line number Diff line
@@ -266,7 +266,8 @@ static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) 
	lc->percpu_offset = __per_cpu_offset[cpu];

	lc->kernel_asce = S390_lowcore.kernel_asce;

	lc->machine_flags = S390_lowcore.machine_flags;

	lc->user_timer = lc->system_timer = lc->steal_timer = 0;

	lc->user_timer = lc->system_timer =

		lc->steal_timer = lc->avg_steal_timer = 0;

	__ctl_store(lc->cregs_save_area, 0, 15);

	save_access_regs((unsigned int *) lc->access_regs_save_area);

	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,

arch/s390/kernel/vtime.c

+12 −7
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ static void account_system_index_scaled(struct task_struct *p, u64 cputime, 
 */

static int do_account_vtime(struct task_struct *tsk)

{

	u64 timer, clock, user, guest, system, hardirq, softirq, steal;

	u64 timer, clock, user, guest, system, hardirq, softirq;



	timer = S390_lowcore.last_update_timer;

	clock = S390_lowcore.last_update_clock;
@@ -182,12 +182,6 @@ static int do_account_vtime(struct task_struct *tsk) 
	if (softirq)

		account_system_index_scaled(tsk, softirq, CPUTIME_SOFTIRQ);



	steal = S390_lowcore.steal_timer;

	if ((s64) steal > 0) {

		S390_lowcore.steal_timer = 0;

		account_steal_time(cputime_to_nsecs(steal));

	}



	return virt_timer_forward(user + guest + system + hardirq + softirq);

}
@@ -213,8 +207,19 @@ void vtime_task_switch(struct task_struct *prev) 
 */

void vtime_flush(struct task_struct *tsk)

{

	u64 steal, avg_steal;



	if (do_account_vtime(tsk))

		virt_timer_expire();



	steal = S390_lowcore.steal_timer;

	avg_steal = S390_lowcore.avg_steal_timer / 2;

	if ((s64) steal > 0) {

		S390_lowcore.steal_timer = 0;

		account_steal_time(steal);

		avg_steal += steal;

	}

	S390_lowcore.avg_steal_timer = avg_steal;

}



/*