[v4,30/46] xen/sched: add support for multiple vcpus per sched unit where missing

Commit Message

Jürgen Groß Sept. 27, 2019, 7 a.m. UTC

In several places there is support for multiple vcpus per sched unit
missing. Add that missing support (with the exception of initial
allocation) and missing helpers for that.

Signed-off-by: Juergen Gross <[e-mail]>
---
RFC V2:
- fix vcpu_runstate_helper()
V1:
- add special handling for idle unit in unit_runnable() and
  unit_runnable_state()
V2:
- handle affinity_broken correctly (Jan Beulich)
V3:
- type for cpu ->unsigned int (Jan Beulich)
---
 xen/common/domain.c        |  5 ++++-
 xen/common/schedule.c      |  9 +++++----
 xen/include/xen/sched-if.h | 16 +++++++++++++++-
 3 files changed, 24 insertions(+), 6 deletions(-)

Comments

Dario Faggioli Sept. 27, 2019, 2:54 p.m. UTC | #1

On Fri, 2019-09-27 at 09:00 +0200, Juergen Gross wrote:
> In several places there is support for multiple vcpus per sched unit
> missing. Add that missing support (with the exception of initial
> allocation) and missing helpers for that.
> 
> Signed-off-by: Juergen Gross <[e-mail]>
>
Reviewed-by: Dario Faggioli <[e-mail]>

Regards

Patch

diff --git a/xen/common/domain.c b/xen/common/domain.c
index 466b9c1b73..ea1225367d 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1273,7 +1273,10 @@  int vcpu_reset(struct vcpu *v)
     v->async_exception_mask = 0;
     memset(v->async_exception_state, 0, sizeof(v->async_exception_state));
 #endif
-    v->affinity_broken = 0;
+    if ( v->affinity_broken & VCPU_AFFINITY_OVERRIDE )
+        vcpu_temporary_affinity(v, NR_CPUS, VCPU_AFFINITY_OVERRIDE);
+    if ( v->affinity_broken & VCPU_AFFINITY_WAIT )
+        vcpu_temporary_affinity(v, NR_CPUS, VCPU_AFFINITY_WAIT);
     clear_bit(_VPF_blocked, &v->pause_flags);
     clear_bit(_VPF_in_reset, &v->pause_flags);
 
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 4f7f195915..fa3d88938a 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -250,8 +250,9 @@  static inline void vcpu_runstate_change(
     s_time_t delta;
     struct sched_unit *unit = v->sched_unit;
 
-    ASSERT(v->runstate.state != new_state);
     ASSERT(spin_is_locked(get_sched_res(v->processor)->schedule_lock));
+    if ( v->runstate.state == new_state )
+        return;
 
     vcpu_urgent_count_update(v);
 
@@ -1727,14 +1728,14 @@  static void sched_switch_units(struct sched_resource *sr,
              (next->vcpu_list->runstate.state == RUNSTATE_runnable) ?
              (now - next->state_entry_time) : 0, prev->next_time);
 
-    ASSERT(prev->vcpu_list->runstate.state == RUNSTATE_running);
+    ASSERT(unit_running(prev));
 
     TRACE_4D(TRC_SCHED_SWITCH, prev->domain->domain_id, prev->unit_id,
              next->domain->domain_id, next->unit_id);
 
     sched_unit_runstate_change(prev, false, now);
 
-    ASSERT(next->vcpu_list->runstate.state != RUNSTATE_running);
+    ASSERT(!unit_running(next));
     sched_unit_runstate_change(next, true, now);
 
     /*
@@ -1856,7 +1857,7 @@  void sched_context_switched(struct vcpu *vprev, struct vcpu *vnext)
             while ( atomic_read(&next->rendezvous_out_cnt) )
                 cpu_relax();
     }
-    else if ( vprev != vnext )
+    else if ( vprev != vnext && sched_granularity == 1 )
         context_saved(vprev);
 }
 
diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index 7e568a9d9f..983f2ece83 100644
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -81,6 +81,11 @@  static inline bool is_unit_online(const struct sched_unit *unit)
     return false;
 }
 
+static inline unsigned int unit_running(const struct sched_unit *unit)
+{
+    return unit->runstate_cnt[RUNSTATE_running];
+}
+
 /* Returns true if at least one vcpu of the unit is runnable. */
 static inline bool unit_runnable(const struct sched_unit *unit)
 {
@@ -126,7 +131,16 @@  static inline bool unit_runnable_state(const struct sched_unit *unit)
 static inline void sched_set_res(struct sched_unit *unit,
                                  struct sched_resource *res)
 {
-    unit->vcpu_list->processor = res->master_cpu;
+    unsigned int cpu = cpumask_first(res->cpus);
+    struct vcpu *v;
+
+    for_each_sched_unit_vcpu ( unit, v )
+    {
+        ASSERT(cpu < nr_cpu_ids);
+        v->processor = cpu;
+        cpu = cpumask_next(cpu, res->cpus);
+    }
+
     unit->res = res;
 }