p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2019-03-06 13:31:21 +02:00
parent 01396a374c
commit 152e9b8676
3 changed files with 45 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
arch/s390/include/asm/lowcore.h
View File

@ -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 */

3
arch/s390/kernel/smp.c
View File

@ -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,

19
arch/s390/kernel/vtime.c
View File

@ -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;
}
/*