[PATCH RFC 23/49] xen/sched: move is_running indicator to struct sched_item

[Juergen Gross <jgross@suse.com>]

Move the is_running indicator from struct vcpu to struct sched_item.
For non-scheduler parts introduce a vcpu_running() access function for
obtaining the related value.

At the same time introduce a state_entry_time field in struct
sched_item being updated whenever the is_running indicator is changed.
Use that new field in the schedulers instead of the similar vcpu field.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 xen/arch/x86/domain.c                |  2 +-
 xen/arch/x86/hvm/hvm.c               |  3 ++-
 xen/arch/x86/hvm/viridian/viridian.c |  1 +
 xen/arch/x86/hvm/vmx/vmcs.c          |  6 ++++--
 xen/arch/x86/hvm/vmx/vmx.c           |  5 +++--
 xen/common/domctl.c                  |  4 ++--
 xen/common/keyhandler.c              |  2 +-
 xen/common/sched_credit.c            | 10 +++++-----
 xen/common/sched_credit2.c           | 18 +++++++++---------
 xen/common/sched_rt.c                |  2 +-
 xen/common/schedule.c                | 19 +++++++++++--------
 xen/include/xen/sched-if.h           | 11 ++++++++++-
 xen/include/xen/sched.h              |  2 --
 13 files changed, 50 insertions(+), 35 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 5d8f3255cb..53b8fa1c9d 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2137,7 +2137,7 @@ void vcpu_kick(struct vcpu *v)
      * NB2. We save the running flag across the unblock to avoid a needless
      * IPI for domains that we IPI'd to unblock.
      */
-    bool running = v->is_running;
+    bool running = vcpu_running(v);
 
     vcpu_unblock(v);
     if ( running && (in_irq() || (v != current)) )
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 8adbb61b57..f184136f81 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -23,6 +23,7 @@
 #include <xen/lib.h>
 #include <xen/trace.h>
 #include <xen/sched.h>
+#include <xen/sched-if.h>
 #include <xen/irq.h>
 #include <xen/softirq.h>
 #include <xen/domain.h>
@@ -3984,7 +3985,7 @@ bool hvm_flush_vcpu_tlb(bool (*flush_vcpu)(void *ctxt, struct vcpu *v),
     /* Now that all VCPUs are signalled to deschedule, we wait... */
     for_each_vcpu ( d, v )
         if ( v != current && flush_vcpu(ctxt, v) )
-            while ( !vcpu_runnable(v) && v->is_running )
+            while ( !vcpu_runnable(v) && vcpu_running(v) )
                 cpu_relax();
 
     /* All other vcpus are paused, safe to unlock now. */
diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c
index 425af56856..5779efc81f 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -6,6 +6,7 @@
  */
 
 #include <xen/sched.h>
+#include <xen/sched-if.h>
 #include <xen/version.h>
 #include <xen/hypercall.h>
 #include <xen/domain_page.h>
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 74f2a08cfd..257fb00528 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -23,6 +23,8 @@
 #include <xen/event.h>
 #include <xen/kernel.h>
 #include <xen/keyhandler.h>
+#include <xen/sched.h>
+#include <xen/sched-if.h>
 #include <xen/vm_event.h>
 #include <asm/current.h>
 #include <asm/cpufeature.h>
@@ -562,7 +564,7 @@ void vmx_vmcs_reload(struct vcpu *v)
      * v->arch.hvm.vmx.vmcs_lock here. However, with interrupts disabled
      * the VMCS can't be taken away from us anymore if we still own it.
      */
-    ASSERT(v->is_running || !local_irq_is_enabled());
+    ASSERT(vcpu_running(v) || !local_irq_is_enabled());
     if ( v->arch.hvm.vmx.vmcs_pa == this_cpu(current_vmcs) )
         return;
 
@@ -1576,7 +1578,7 @@ void vmx_vcpu_flush_pml_buffer(struct vcpu *v)
     uint64_t *pml_buf;
     unsigned long pml_idx;
 
-    ASSERT((v == current) || (!vcpu_runnable(v) && !v->is_running));
+    ASSERT((v == current) || (!vcpu_runnable(v) && !vcpu_running(v)));
     ASSERT(vmx_vcpu_pml_enabled(v));
 
     vmx_vmcs_enter(v);
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 725dd88c13..0056fd0191 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -19,6 +19,7 @@
 #include <xen/lib.h>
 #include <xen/trace.h>
 #include <xen/sched.h>
+#include <xen/sched-if.h>
 #include <xen/irq.h>
 #include <xen/softirq.h>
 #include <xen/domain_page.h>
@@ -907,7 +908,7 @@ static void vmx_ctxt_switch_from(struct vcpu *v)
     if ( unlikely(!this_cpu(vmxon)) )
         return;
 
-    if ( !v->is_running )
+    if ( !vcpu_running(v) )
     {
         /*
          * When this vCPU isn't marked as running anymore, a remote pCPU's
@@ -2004,7 +2005,7 @@ static void vmx_process_isr(int isr, struct vcpu *v)
 
 static void __vmx_deliver_posted_interrupt(struct vcpu *v)
 {
-    bool_t running = v->is_running;
+    bool_t running = vcpu_running(v);
 
     vcpu_unblock(v);
     /*
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 8464713d2b..6a9a54130d 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -173,7 +173,7 @@ void getdomaininfo(struct domain *d, struct xen_domctl_getdomaininfo *info)
         {
             if ( !(v->pause_flags & VPF_blocked) )
                 flags &= ~XEN_DOMINF_blocked;
-            if ( v->is_running )
+            if ( vcpu_running(v) )
                 flags |= XEN_DOMINF_running;
             info->nr_online_vcpus++;
         }
@@ -841,7 +841,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
 
         op->u.getvcpuinfo.online   = !(v->pause_flags & VPF_down);
         op->u.getvcpuinfo.blocked  = !!(v->pause_flags & VPF_blocked);
-        op->u.getvcpuinfo.running  = v->is_running;
+        op->u.getvcpuinfo.running  = vcpu_running(v);
         op->u.getvcpuinfo.cpu_time = runstate.time[RUNSTATE_running];
         op->u.getvcpuinfo.cpu      = v->processor;
         ret = 0;
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index f50df5841d..0d312ff953 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -306,7 +306,7 @@ static void dump_domains(unsigned char key)
             printk("    VCPU%d: CPU%d [has=%c] poll=%d "
                    "upcall_pend=%02x upcall_mask=%02x ",
                    v->vcpu_id, v->processor,
-                   v->is_running ? 'T':'F', v->poll_evtchn,
+                   vcpu_running(v) ? 'T':'F', v->poll_evtchn,
                    vcpu_info(v, evtchn_upcall_pending),
                    !vcpu_event_delivery_is_enabled(v));
             if ( vcpu_cpu_dirty(v) )
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c
index 29076e362b..6d0639109a 100644
--- a/xen/common/sched_credit.c
+++ b/xen/common/sched_credit.c
@@ -723,7 +723,7 @@ __csched_vcpu_is_migrateable(const struct csched_private *prv, struct vcpu *vc,
      * The caller is supposed to have already checked that vc is also
      * not running.
      */
-    ASSERT(!vc->is_running);
+    ASSERT(!vcpu_running(vc));
 
     return !__csched_vcpu_is_cache_hot(prv, vc) &&
            cpumask_test_cpu(dest_cpu, mask);
@@ -1047,7 +1047,7 @@ csched_item_insert(const struct scheduler *ops, struct sched_item *item)
 
     lock = item_schedule_lock_irq(item);
 
-    if ( !__vcpu_on_runq(svc) && vcpu_runnable(vc) && !vc->is_running )
+    if ( !__vcpu_on_runq(svc) && vcpu_runnable(vc) && !vcpu_running(vc) )
         runq_insert(svc);
 
     item_schedule_unlock_irq(lock, item);
@@ -1659,8 +1659,8 @@ csched_runq_steal(int peer_cpu, int cpu, int pri, int balance_step)
          * vCPUs with useful soft affinities in some sort of bitmap
          * or counter.
          */
-        if ( vc->is_running || (balance_step == BALANCE_SOFT_AFFINITY &&
-                                !has_soft_affinity(vc->sched_item)) )
+        if ( vcpu_running(vc) || (balance_step == BALANCE_SOFT_AFFINITY &&
+                                  !has_soft_affinity(vc->sched_item)) )
             continue;
 
         affinity_balance_cpumask(vc->sched_item, balance_step, cpumask_scratch);
@@ -1868,7 +1868,7 @@ csched_schedule(
                     (unsigned char *)&d);
     }
 
-    runtime = now - current->runstate.state_entry_time;
+    runtime = now - current->sched_item->state_entry_time;
     if ( runtime < 0 ) /* Does this ever happen? */
         runtime = 0;
 
diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
index 9bf045d20f..5aa819b2c5 100644
--- a/xen/common/sched_credit2.c
+++ b/xen/common/sched_credit2.c
@@ -1283,7 +1283,7 @@ runq_insert(const struct scheduler *ops, struct csched2_item *svc)
 
     ASSERT(&svc->rqd->runq == runq);
     ASSERT(!is_idle_vcpu(svc->vcpu));
-    ASSERT(!svc->vcpu->is_running);
+    ASSERT(!vcpu_running(svc->vcpu));
     ASSERT(!(svc->flags & CSFLAG_scheduled));
 
     list_for_each( iter, runq )
@@ -1340,8 +1340,8 @@ static inline bool is_preemptable(const struct csched2_item *svc,
     if ( ratelimit <= CSCHED2_RATELIMIT_TICKLE_TOLERANCE )
         return true;
 
-    ASSERT(svc->vcpu->is_running);
-    return now - svc->vcpu->runstate.state_entry_time >
+    ASSERT(vcpu_running(svc->vcpu));
+    return now - svc->vcpu->sched_item->state_entry_time >
            ratelimit - CSCHED2_RATELIMIT_TICKLE_TOLERANCE;
 }
 
@@ -2931,7 +2931,7 @@ csched2_dom_cntl(
                 {
                     svc = csched2_item(v->sched_item);
                     lock = item_schedule_lock(svc->vcpu->sched_item);
-                    if ( v->is_running )
+                    if ( vcpu_running(v) )
                     {
                         unsigned int cpu = v->processor;
                         struct csched2_runqueue_data *rqd = c2rqd(ops, cpu);
@@ -3204,8 +3204,8 @@ csched2_runtime(const struct scheduler *ops, int cpu,
     if ( prv->ratelimit_us )
     {
         s_time_t ratelimit_min = MICROSECS(prv->ratelimit_us);
-        if ( snext->vcpu->is_running )
-            ratelimit_min = snext->vcpu->runstate.state_entry_time +
+        if ( vcpu_running(snext->vcpu) )
+            ratelimit_min = snext->vcpu->sched_item->state_entry_time +
                             MICROSECS(prv->ratelimit_us) - now;
         if ( ratelimit_min > min_time )
             min_time = ratelimit_min;
@@ -3302,7 +3302,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
      * no point forcing it to do so until rate limiting expires.
      */
     if ( !yield && prv->ratelimit_us && vcpu_runnable(scurr->vcpu) &&
-         (now - scurr->vcpu->runstate.state_entry_time) <
+         (now - scurr->vcpu->sched_item->state_entry_time) <
           MICROSECS(prv->ratelimit_us) )
     {
         if ( unlikely(tb_init_done) )
@@ -3313,7 +3313,7 @@ runq_candidate(struct csched2_runqueue_data *rqd,
             } d;
             d.dom = scurr->vcpu->domain->domain_id;
             d.vcpu = scurr->vcpu->vcpu_id;
-            d.runtime = now - scurr->vcpu->runstate.state_entry_time;
+            d.runtime = now - scurr->vcpu->sched_item->state_entry_time;
             __trace_var(TRC_CSCHED2_RATELIMIT, 1,
                         sizeof(d),
                         (unsigned char *)&d);
@@ -3561,7 +3561,7 @@ csched2_schedule(
         if ( snext != scurr )
         {
             ASSERT(snext->rqd == rqd);
-            ASSERT(!snext->vcpu->is_running);
+            ASSERT(!vcpu_running(snext->vcpu));
 
             runq_remove(snext);
             __set_bit(__CSFLAG_scheduled, &snext->flags);
diff --git a/xen/common/sched_rt.c b/xen/common/sched_rt.c
index 374a9d2383..9efe807230 100644
--- a/xen/common/sched_rt.c
+++ b/xen/common/sched_rt.c
@@ -914,7 +914,7 @@ rt_item_insert(const struct scheduler *ops, struct sched_item *item)
     {
         replq_insert(ops, svc);
 
-        if ( !vc->is_running )
+        if ( !vcpu_running(vc) )
             runq_insert(ops, svc);
     }
     item_schedule_unlock_irq(lock, item);
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index b295b0b81e..ae2a6d0323 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -356,7 +356,8 @@ int sched_init_vcpu(struct vcpu *v, unsigned int processor)
     if ( is_idle_domain(d) )
     {
         per_cpu(sched_res, v->processor)->curr = item;
-        v->is_running = 1;
+        item->is_running = 1;
+        item->state_entry_time = NOW();
     }
     else
     {
@@ -555,7 +556,7 @@ void vcpu_sleep_sync(struct vcpu *v)
 {
     vcpu_sleep_nosync(v);
 
-    while ( !vcpu_runnable(v) && v->is_running )
+    while ( !vcpu_runnable(v) && vcpu_running(v) )
         cpu_relax();
 
     sync_vcpu_execstate(v);
@@ -680,7 +681,7 @@ static void vcpu_migrate_finish(struct vcpu *v)
      * context_saved(); and in any case, if the bit is cleared, then
      * someone else has already done the work so we don't need to.
      */
-    if ( v->is_running || !test_bit(_VPF_migrating, &v->pause_flags) )
+    if ( vcpu_running(v) || !test_bit(_VPF_migrating, &v->pause_flags) )
         return;
 
     old_cpu = new_cpu = v->processor;
@@ -734,7 +735,7 @@ static void vcpu_migrate_finish(struct vcpu *v)
      * because they both happen in (different) spinlock regions, and those
      * regions are strictly serialised.
      */
-    if ( v->is_running ||
+    if ( vcpu_running(v) ||
          !test_and_clear_bit(_VPF_migrating, &v->pause_flags) )
     {
         sched_spin_unlock_double(old_lock, new_lock, flags);
@@ -762,7 +763,7 @@ void vcpu_force_reschedule(struct vcpu *v)
 {
     spinlock_t *lock = item_schedule_lock_irq(v->sched_item);
 
-    if ( v->is_running )
+    if ( vcpu_running(v) )
         vcpu_migrate_start(v);
 
     item_schedule_unlock_irq(lock, v->sched_item);
@@ -1597,8 +1598,9 @@ static void schedule(void)
      * switch, else lost_records resume will not work properly.
      */
 
-    ASSERT(!next->is_running);
-    next->is_running = 1;
+    ASSERT(!vcpu_running(next));
+    next->sched_item->is_running = 1;
+    next->sched_item->state_entry_time = now;
 
     pcpu_schedule_unlock_irq(lock, cpu);
 
@@ -1619,7 +1621,8 @@ void context_saved(struct vcpu *prev)
     /* Clear running flag /after/ writing context to memory. */
     smp_wmb();
 
-    prev->is_running = 0;
+    prev->sched_item->is_running = 0;
+    prev->sched_item->state_entry_time = NOW();
 
     /* Check for migration request /after/ clearing running flag. */
     smp_mb();
diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index 3dcf1dca19..5cacede473 100644
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -59,8 +59,12 @@ struct sched_item {
 
     /* Last time when item has been scheduled out. */
     uint64_t               last_run_time;
+    /* Last time item got (de-)scheduled. */
+    uint64_t               state_entry_time;
 
-    /* Item needs affinity restored. */
+    /* Currently running on a CPU? */
+    bool                   is_running;
+    /* Item needs affinity restored */
     bool                   affinity_broken;
     /* Does soft affinity actually play a role (given hard affinity)? */
     bool                   soft_aff_effective;
@@ -132,6 +136,11 @@ static inline struct sched_item *sched_idle_item(unsigned int cpu)
     return idle_vcpu[cpu]->sched_item;
 }
 
+static inline bool vcpu_running(struct vcpu *v)
+{
+    return v->sched_item->is_running;
+}
+
 /*
  * Scratch space, for avoiding having too many cpumask_t on the stack.
  * Within each scheduler, when using the scratch mask of one pCPU:
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 4b59de42da..21a7fa14ce 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -181,8 +181,6 @@ struct vcpu
     bool             fpu_dirtied;
     /* Initialization completed for this VCPU? */
     bool             is_initialised;
-    /* Currently running on a CPU? */
-    bool             is_running;
     /* VCPU should wake fast (do not deep sleep the CPU). */
     bool             is_urgent;
 
-- 
2.16.4


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