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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-24 09:07:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-24 09:07:03 -0700
commit5fabc487c96819dd12ddb9414835d170fd9cd6d5 (patch)
tree01532d492e5074b0d3add29bf92ebf9a9d161e9e /kernel/sched.c
parentc61264f98c1a974ee6f545f61a4ab33b141d6bda (diff)
parent3f68b0318bbbd61bf08478ab99a149f0d9e5156e (diff)
downloadlwn-5fabc487c96819dd12ddb9414835d170fd9cd6d5.tar.gz
lwn-5fabc487c96819dd12ddb9414835d170fd9cd6d5.zip
Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits) KVM: IOMMU: Disable device assignment without interrupt remapping KVM: MMU: trace mmio page fault KVM: MMU: mmio page fault support KVM: MMU: reorganize struct kvm_shadow_walk_iterator KVM: MMU: lockless walking shadow page table KVM: MMU: do not need atomicly to set/clear spte KVM: MMU: introduce the rules to modify shadow page table KVM: MMU: abstract some functions to handle fault pfn KVM: MMU: filter out the mmio pfn from the fault pfn KVM: MMU: remove bypass_guest_pf KVM: MMU: split kvm_mmu_free_page KVM: MMU: count used shadow pages on prepareing path KVM: MMU: rename 'pt_write' to 'emulate' KVM: MMU: cleanup for FNAME(fetch) KVM: MMU: optimize to handle dirty bit KVM: MMU: cache mmio info on page fault path KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code KVM: MMU: do not update slot bitmap if spte is nonpresent KVM: MMU: fix walking shadow page table KVM guest: KVM Steal time registration ...
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c90
1 files changed, 80 insertions, 10 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 9aaf567c5da5..751a7cc6a5cd 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,6 +75,9 @@
#include <asm/tlb.h>
#include <asm/irq_regs.h>
#include <asm/mutex.h>
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#endif
#include "sched_cpupri.h"
#include "workqueue_sched.h"
@@ -528,6 +531,12 @@ struct rq {
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
u64 prev_irq_time;
#endif
+#ifdef CONFIG_PARAVIRT
+ u64 prev_steal_time;
+#endif
+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
+ u64 prev_steal_time_rq;
+#endif
/* calc_load related fields */
unsigned long calc_load_update;
@@ -1921,10 +1930,28 @@ void account_system_vtime(struct task_struct *curr)
}
EXPORT_SYMBOL_GPL(account_system_vtime);
-static void update_rq_clock_task(struct rq *rq, s64 delta)
+#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
+
+#ifdef CONFIG_PARAVIRT
+static inline u64 steal_ticks(u64 steal)
{
- s64 irq_delta;
+ if (unlikely(steal > NSEC_PER_SEC))
+ return div_u64(steal, TICK_NSEC);
+ return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
+}
+#endif
+
+static void update_rq_clock_task(struct rq *rq, s64 delta)
+{
+/*
+ * In theory, the compile should just see 0 here, and optimize out the call
+ * to sched_rt_avg_update. But I don't trust it...
+ */
+#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
+ s64 steal = 0, irq_delta = 0;
+#endif
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
/*
@@ -1947,12 +1974,35 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
rq->prev_irq_time += irq_delta;
delta -= irq_delta;
+#endif
+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
+ if (static_branch((&paravirt_steal_rq_enabled))) {
+ u64 st;
+
+ steal = paravirt_steal_clock(cpu_of(rq));
+ steal -= rq->prev_steal_time_rq;
+
+ if (unlikely(steal > delta))
+ steal = delta;
+
+ st = steal_ticks(steal);
+ steal = st * TICK_NSEC;
+
+ rq->prev_steal_time_rq += steal;
+
+ delta -= steal;
+ }
+#endif
+
rq->clock_task += delta;
- if (irq_delta && sched_feat(NONIRQ_POWER))
- sched_rt_avg_update(rq, irq_delta);
+#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
+ if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
+ sched_rt_avg_update(rq, irq_delta + steal);
+#endif
}
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
static int irqtime_account_hi_update(void)
{
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
@@ -1987,12 +2037,7 @@ static int irqtime_account_si_update(void)
#define sched_clock_irqtime (0)
-static void update_rq_clock_task(struct rq *rq, s64 delta)
-{
- rq->clock_task += delta;
-}
-
-#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
+#endif
#include "sched_idletask.c"
#include "sched_fair.c"
@@ -3845,6 +3890,25 @@ void account_idle_time(cputime_t cputime)
cpustat->idle = cputime64_add(cpustat->idle, cputime64);
}
+static __always_inline bool steal_account_process_tick(void)
+{
+#ifdef CONFIG_PARAVIRT
+ if (static_branch(&paravirt_steal_enabled)) {
+ u64 steal, st = 0;
+
+ steal = paravirt_steal_clock(smp_processor_id());
+ steal -= this_rq()->prev_steal_time;
+
+ st = steal_ticks(steal);
+ this_rq()->prev_steal_time += st * TICK_NSEC;
+
+ account_steal_time(st);
+ return st;
+ }
+#endif
+ return false;
+}
+
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -3876,6 +3940,9 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy);
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+ if (steal_account_process_tick())
+ return;
+
if (irqtime_account_hi_update()) {
cpustat->irq = cputime64_add(cpustat->irq, tmp);
} else if (irqtime_account_si_update()) {
@@ -3929,6 +3996,9 @@ void account_process_tick(struct task_struct *p, int user_tick)
return;
}
+ if (steal_account_process_tick())
+ return;
+
if (user_tick)
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))