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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH 4/4] Changed filenames with sedf to cbs to reflect the actual scheduler
From: Robbie VanVossen <robert.vanvossen@xxxxxxxxxxxxxxx>
---
tools/libxc/Makefile | 2 +-
tools/libxc/xc_cbs.c | 70 ++++
tools/libxc/xc_sedf.c | 70 ----
xen/common/Makefile | 2 +-
xen/common/sched_cbs.c | 917 +++++++++++++++++++++++++++++++++++++++++++++++
xen/common/sched_sedf.c | 917 -----------------------------------------------
6 files changed, 989 insertions(+), 989 deletions(-)
create mode 100755 tools/libxc/xc_cbs.c
delete mode 100755 tools/libxc/xc_sedf.c
create mode 100644 xen/common/sched_cbs.c
delete mode 100644 xen/common/sched_sedf.c
diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index a74b19e..dc06e59 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -16,7 +16,7 @@ CTRL_SRCS-y += xc_misc.c
CTRL_SRCS-y += xc_flask.c
CTRL_SRCS-y += xc_physdev.c
CTRL_SRCS-y += xc_private.c
-CTRL_SRCS-y += xc_sedf.c
+CTRL_SRCS-y += xc_cbs.c
CTRL_SRCS-y += xc_csched.c
CTRL_SRCS-y += xc_csched2.c
CTRL_SRCS-y += xc_arinc653.c
diff --git a/tools/libxc/xc_cbs.c b/tools/libxc/xc_cbs.c
new file mode 100755
index 0000000..3b578d1
--- /dev/null
+++ b/tools/libxc/xc_cbs.c
@@ -0,0 +1,70 @@
+/******************************************************************************
+ * xc_cbs.c
+ *
+ * API for manipulating parameters of the CBS scheduler.
+ *
+ * changes by Stephan Diestelhorst
+ * based on code
+ * by Mark Williamson, Copyright (c) 2004 Intel Research Cambridge.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
USA
+ */
+
+#include "xc_private.h"
+
+int xc_cbs_domain_set(
+ xc_interface *xch,
+ uint32_t domid,
+ uint64_t period,
+ uint64_t budget,
+ uint16_t soft)
+{
+ DECLARE_DOMCTL;
+ struct xen_domctl_sched_cbs *p = &domctl.u.scheduler_op.u.cbs;
+
+ domctl.cmd = XEN_DOMCTL_scheduler_op;
+ domctl.domain = (domid_t)domid;
+ domctl.u.scheduler_op.sched_id = XEN_SCHEDULER_CBS;
+ domctl.u.scheduler_op.cmd = XEN_DOMCTL_SCHEDOP_putinfo;
+
+ p->period = period;
+ p->budget = budget;
+ p->soft = soft;
+ return do_domctl(xch, &domctl);
+}
+
+int xc_cbs_domain_get(
+ xc_interface *xch,
+ uint32_t domid,
+ uint64_t *period,
+ uint64_t *budget,
+ uint16_t *soft)
+{
+ DECLARE_DOMCTL;
+ int ret;
+ struct xen_domctl_sched_cbs *p = &domctl.u.scheduler_op.u.cbs;
+
+ domctl.cmd = XEN_DOMCTL_scheduler_op;
+ domctl.domain = (domid_t)domid;
+ domctl.u.scheduler_op.sched_id = XEN_SCHEDULER_CBS;
+ domctl.u.scheduler_op.cmd = XEN_DOMCTL_SCHEDOP_getinfo;
+
+ ret = do_domctl(xch, &domctl);
+
+ *period = p->period;
+ *budget = p->budget;
+ *soft = p->soft;
+ return ret;
+}
diff --git a/tools/libxc/xc_sedf.c b/tools/libxc/xc_sedf.c
deleted file mode 100755
index 3b578d1..0000000
--- a/tools/libxc/xc_sedf.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/******************************************************************************
- * xc_cbs.c
- *
- * API for manipulating parameters of the CBS scheduler.
- *
- * changes by Stephan Diestelhorst
- * based on code
- * by Mark Williamson, Copyright (c) 2004 Intel Research Cambridge.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
USA
- */
-
-#include "xc_private.h"
-
-int xc_cbs_domain_set(
- xc_interface *xch,
- uint32_t domid,
- uint64_t period,
- uint64_t budget,
- uint16_t soft)
-{
- DECLARE_DOMCTL;
- struct xen_domctl_sched_cbs *p = &domctl.u.scheduler_op.u.cbs;
-
- domctl.cmd = XEN_DOMCTL_scheduler_op;
- domctl.domain = (domid_t)domid;
- domctl.u.scheduler_op.sched_id = XEN_SCHEDULER_CBS;
- domctl.u.scheduler_op.cmd = XEN_DOMCTL_SCHEDOP_putinfo;
-
- p->period = period;
- p->budget = budget;
- p->soft = soft;
- return do_domctl(xch, &domctl);
-}
-
-int xc_cbs_domain_get(
- xc_interface *xch,
- uint32_t domid,
- uint64_t *period,
- uint64_t *budget,
- uint16_t *soft)
-{
- DECLARE_DOMCTL;
- int ret;
- struct xen_domctl_sched_cbs *p = &domctl.u.scheduler_op.u.cbs;
-
- domctl.cmd = XEN_DOMCTL_scheduler_op;
- domctl.domain = (domid_t)domid;
- domctl.u.scheduler_op.sched_id = XEN_SCHEDULER_CBS;
- domctl.u.scheduler_op.cmd = XEN_DOMCTL_SCHEDOP_getinfo;
-
- ret = do_domctl(xch, &domctl);
-
- *period = p->period;
- *budget = p->budget;
- *soft = p->soft;
- return ret;
-}
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 3683ae3..f2cb709 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -24,7 +24,7 @@ obj-y += random.o
obj-y += rangeset.o
obj-y += sched_credit.o
obj-y += sched_credit2.o
-obj-y += sched_sedf.o
+obj-y += sched_cbs.o
obj-y += sched_arinc653.o
obj-y += schedule.o
obj-y += shutdown.o
diff --git a/xen/common/sched_cbs.c b/xen/common/sched_cbs.c
new file mode 100644
index 0000000..5df4825
--- /dev/null
+++ b/xen/common/sched_cbs.c
@@ -0,0 +1,917 @@
+/******************************************************************************
+ * Constant Bandwidth Server Scheduler for Xen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * by DornerWorks Ltd. (C) 2014 Grand Rapids, MI
+ *
+ * Adapted from code by Stephan Diestelhorst (C) 2004 Cambridge University
+ * and Mark Williamson (C) 2004 Intel Research Cambridge
+ *
+ */
+
+#include <xen/lib.h>
+#include <xen/sched.h>
+#include <xen/sched-if.h>
+#include <xen/timer.h>
+#include <xen/softirq.h>
+#include <xen/time.h>
+#include <xen/errno.h>
+
+#ifndef NDEBUG
+#define CBS_STATS
+#define CHECK(_p) \
+ do { \
+ if ( !(_p) ) \
+ printk("Check '%s' failed, line %d, file %s\n", \
+ #_p , __LINE__, __FILE__); \
+ } while ( 0 )
+#else
+#define CHECK(_p) ((void)0)
+#endif
+
+#define CBS_SOFT_TASK (1)
+#define CBS_ASLEEP (16)
+
+#define DEFAULT_PERIOD (MILLISECS(20))
+#define DEFAULT_BUDGET (MILLISECS(10))
+
+#define PERIOD_MAX MILLISECS(10000) /* 10s */
+#define PERIOD_MIN (MICROSECS(10)) /* 10us */
+#define BUDGET_MIN (MICROSECS(5)) /* 5us */
+
+#define EQ(_A, _B) ((!!(_A)) == (!!(_B)))
+
+
+struct cbs_dom_info {
+ struct domain *domain;
+};
+
+struct cbs_priv_info {
+ /* lock for the whole pluggable scheduler, nests inside cpupool_lock */
+ spinlock_t lock;
+};
+
+struct cbs_vcpu_info {
+ struct vcpu *vcpu;
+ struct list_head list;
+
+
+ /* Parameters for EDF-CBS */
+ s_time_t period; /* = Server scheduling period */
+ s_time_t budget; /* = Guarenteed minimum CPU time per period */
+ /* Note: Server bandwidth = (budget / period) */
+
+ /* Status of vcpu */
+ int status;
+ /* Bookkeeping */
+ s_time_t deadl_abs;
+ s_time_t sched_start_abs;
+ s_time_t cputime;
+ /* Times the vcpu un-/blocked */
+ s_time_t block_abs;
+ s_time_t unblock_abs;
+
+#ifdef CBS_STATS
+ s_time_t block_time_tot;
+ int block_tot;
+ int short_block_tot;
+ int long_block_tot;
+ s_time_t miss_time;
+ s_time_t over_time;
+ int miss_tot;
+ int over_tot;
+#endif
+};
+
+struct cbs_cpu_info {
+ struct list_head runnableq;
+ struct list_head waitq;
+ s_time_t current_budget_expires;
+};
+
+#define CBS_PRIV(_ops) \
+ ((struct cbs_priv_info *)((_ops)->sched_data))
+#define CBS_VCPU(_vcpu) ((struct cbs_vcpu_info *)((_vcpu)->sched_priv))
+#define CBS_PCPU(_cpu) \
+ ((struct cbs_cpu_info *)per_cpu(schedule_data, _cpu).sched_priv)
+#define LIST(_vcpu) (&CBS_VCPU(_vcpu)->list)
+#define RUNQ(_cpu) (&CBS_PCPU(_cpu)->runnableq)
+#define WAITQ(_cpu) (&CBS_PCPU(_cpu)->waitq)
+#define IDLETASK(_cpu) (idle_vcpu[_cpu])
+
+#define PERIOD_BEGIN(inf) ((inf)->deadl_abs - (inf)->period)
+
+#define DIV_UP(_X, _Y) (((_X) + (_Y) - 1) / _Y)
+
+#define cbs_runnable(edom) (!(CBS_VCPU(edom)->status & CBS_ASLEEP))
+
+#define cbs_soft(edom) (CBS_VCPU(edom)->status & CBS_SOFT_TASK)
+
+static void cbs_dump_cpu_state(const struct scheduler *ops, int cpu);
+
+static inline int __task_on_queue(struct vcpu *v)
+{
+ return (((LIST(v))->next != NULL) && (LIST(v)->next != LIST(v)));
+}
+
+static inline void __del_from_queue(struct vcpu *v)
+{
+ struct list_head *list = LIST(v);
+ ASSERT(__task_on_queue(v));
+ list_del(list);
+ list->next = NULL;
+ ASSERT(!__task_on_queue(v));
+}
+
+typedef int(*list_comparer)(struct list_head* el1, struct list_head* el2);
+
+static inline void list_insert_sort(
+ struct list_head *list, struct list_head *element, list_comparer comp)
+{
+ struct list_head *cur;
+
+ /* Iterate through all elements to find our "hole" */
+ list_for_each( cur, list )
+ if ( comp(element, cur) < 0 )
+ break;
+
+ /* cur now contains the element, before which we'll enqueue */
+ list_add(element, cur->prev);
+}
+
+#define VCPU_COMPARER(name, field, comp1, comp2) \
+static int name##_comp(struct list_head* el1, struct list_head* el2) \
+{ \
+ struct cbs_vcpu_info *v1, *v2; \
+ v1 = list_entry(el1, struct cbs_vcpu_info, field); \
+ v2 = list_entry(el2, struct cbs_vcpu_info, field); \
+ if ( (comp1) == (comp2) ) \
+ return 0; \
+ if ( (comp1) < (comp2) ) \
+ return -1; \
+ else \
+ return 1; \
+}
+
+/*
+ * Adds a vcpu to the queue of processes which wait for the beginning of the
+ * next period; this list is therefore sortet by this time, which is simply
+ * absol. deadline - period.
+ */
+VCPU_COMPARER(waitq, list, PERIOD_BEGIN(v1), PERIOD_BEGIN(v2));
+static inline void __add_to_waitqueue_sort(struct vcpu *v)
+{
+ ASSERT(!__task_on_queue(v));
+ list_insert_sort(WAITQ(v->processor), LIST(v), waitq_comp);
+ ASSERT(__task_on_queue(v));
+}
+
+/*
+ * Adds a vcpu to the queue of processes which have started their current
+ * period and are runnable (i.e. not blocked, dieing,...). The first element
+ * on this list is running on the processor, if the list is empty the idle
+ * task will run. As we are implementing EDF, this list is sorted by deadlines.
+ */
+VCPU_COMPARER(runq, list, v1->deadl_abs, v2->deadl_abs);
+static inline void __add_to_runqueue_sort(struct vcpu *v)
+{
+ list_insert_sort(RUNQ(v->processor), LIST(v), runq_comp);
+}
+
+
+static void cbs_insert_vcpu(const struct scheduler *ops, struct vcpu *v)
+{
+ if ( is_idle_vcpu(v) )
+ {
+ CBS_VCPU(v)->deadl_abs = 0;
+ CBS_VCPU(v)->status &= ~CBS_ASLEEP;
+ }
+}
+
+static void *cbs_alloc_vdata(const struct scheduler *ops, struct vcpu *v, void
*dd)
+{
+ struct cbs_vcpu_info *inf;
+
+ inf = xzalloc(struct cbs_vcpu_info);
+ if ( inf == NULL )
+ return NULL;
+
+ inf->vcpu = v;
+
+ inf->deadl_abs = 0;
+ inf->cputime = 0;
+ inf->status = CBS_ASLEEP;
+
+ if (v->domain->domain_id == 0)
+ {
+ /* Domain 0, needs a budget to boot the machine */
+ inf->period = DEFAULT_PERIOD;
+ inf->budget = DEFAULT_BUDGET;
+ }
+ else
+ {
+ inf->period = DEFAULT_PERIOD;
+ inf->budget = 0;
+ }
+
+ INIT_LIST_HEAD(&(inf->list));
+
+ SCHED_STAT_CRANK(vcpu_init);
+
+ return inf;
+}
+
+static void *
+cbs_alloc_pdata(const struct scheduler *ops, int cpu)
+{
+ struct cbs_cpu_info *spc;
+
+ spc = xzalloc(struct cbs_cpu_info);
+ BUG_ON(spc == NULL);
+ INIT_LIST_HEAD(&spc->waitq);
+ INIT_LIST_HEAD(&spc->runnableq);
+
+ return (void *)spc;
+}
+
+static void
+cbs_free_pdata(const struct scheduler *ops, void *spc, int cpu)
+{
+ if ( spc == NULL )
+ return;
+
+ xfree(spc);
+}
+
+static void cbs_free_vdata(const struct scheduler *ops, void *priv)
+{
+ xfree(priv);
+}
+
+static void *
+cbs_alloc_domdata(const struct scheduler *ops, struct domain *d)
+{
+ return xzalloc(struct cbs_dom_info);
+}
+
+static int cbs_init_domain(const struct scheduler *ops, struct domain *d)
+{
+ d->sched_priv = cbs_alloc_domdata(ops, d);
+ if ( d->sched_priv == NULL )
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void cbs_free_domdata(const struct scheduler *ops, void *data)
+{
+ xfree(data);
+}
+
+static void cbs_destroy_domain(const struct scheduler *ops, struct domain *d)
+{
+ cbs_free_domdata(ops, d->sched_priv);
+}
+
+static int cbs_pick_cpu(const struct scheduler *ops, struct vcpu *v)
+{
+ cpumask_t online_affinity;
+ cpumask_t *online;
+
+ online = cpupool_scheduler_cpumask(v->domain->cpupool);
+ cpumask_and(&online_affinity, v->cpu_affinity, online);
+ return cpumask_cycle(v->vcpu_id % cpumask_weight(&online_affinity) - 1,
+ &online_affinity);
+}
+
+/*
+ * Handles the rescheduling & bookkeeping of vcpus running in their
+ * guaranteed time budget.
+ */
+static void desched_edf_vcpu(s_time_t now, struct vcpu *v)
+{
+ struct cbs_vcpu_info* inf = CBS_VCPU(v);
+
+ /* Current vcpu is running in real time mode */
+ ASSERT(__task_on_queue(v));
+
+ /* Update the vcpu's cputime */
+ inf->cputime += now - inf->sched_start_abs;
+
+ /* Scheduling decisions which don't remove the running vcpu from
+ * the runq */
+ if ( (inf->cputime < inf->budget) && cbs_runnable(v) )
+ return;
+
+ __del_from_queue(v);
+
+#ifdef CBS_STATS
+ /* Manage deadline misses */
+ if ( unlikely(inf->deadl_abs < now) )
+ {
+ inf->miss_tot++;
+ inf->miss_time += inf->cputime;
+ }
+#endif
+
+ /* Manage overruns */
+ if ( inf->cputime >= inf->budget )
+ {
+ inf->cputime -= inf->budget;
+
+
+ /* Set next deadline */
+ inf->deadl_abs += inf->period;
+
+ /* Ensure that the cputime is always less than budget */
+ if ( unlikely(inf->cputime > inf->budget) )
+ {
+#ifdef CBS_STATS
+ inf->over_tot++;
+ inf->over_time += inf->cputime;
+#endif
+
+ /* Make up for the overage by pushing the deadline
+ into the future */
+ inf->deadl_abs += ((inf->cputime / inf->budget)
+ * inf->period) * 2;
+ inf->cputime -= (inf->cputime / inf->budget) * inf->budget;
+ }
+
+ /* Ensure that the start of the next period is in the future */
+ if ( unlikely(PERIOD_BEGIN(inf) < now) )
+ inf->deadl_abs +=
+ (DIV_UP(now - PERIOD_BEGIN(inf),
+ inf->period)) * inf->period;
+ }
+
+ /* Add a runnable vcpu to the appropriate queue */
+ if ( cbs_runnable(v) )
+ {
+ if( cbs_soft(v) )
+ {
+ __add_to_runqueue_sort(v);
+ }
+ else
+ {
+ __add_to_waitqueue_sort(v);
+ }
+ }
+
+ ASSERT(EQ(cbs_runnable(v), __task_on_queue(v)));
+}
+
+
+/* Update all elements on the queues */
+static void update_queues(
+ s_time_t now, struct list_head *runq, struct list_head *waitq)
+{
+ struct list_head *cur, *tmp;
+ struct cbs_vcpu_info *curinf;
+
+ /*
+ * Check for the first elements of the waitqueue, whether their
+ * next period has already started.
+ */
+ list_for_each_safe ( cur, tmp, waitq )
+ {
+ curinf = list_entry(cur, struct cbs_vcpu_info, list);
+ if ( PERIOD_BEGIN(curinf) > now )
+ break;
+ __del_from_queue(curinf->vcpu);
+ __add_to_runqueue_sort(curinf->vcpu);
+ }
+
+ /* Process the runq, find vcpus that are on the runq that shouldn't */
+ list_for_each_safe ( cur, tmp, runq )
+ {
+ curinf = list_entry(cur, struct cbs_vcpu_info, list);
+
+ if ( unlikely(curinf->budget == 0) )
+ {
+ /* Ignore vcpus with empty budget */
+ __del_from_queue(curinf->vcpu);
+
+ /* Move them to their next period */
+ curinf->deadl_abs += curinf->period;
+
+ /* Ensure that the start of the next period is in the future */
+ if ( unlikely(PERIOD_BEGIN(curinf) < now) )
+ curinf->deadl_abs +=
+ (DIV_UP(now - PERIOD_BEGIN(curinf),
+ curinf->period)) * curinf->period;
+
+ /* Put them back into the queue */
+ __add_to_waitqueue_sort(curinf->vcpu);
+ }
+
+ else
+ break;
+ }
+}
+
+
+static int cbs_init(struct scheduler *ops)
+{
+ struct cbs_priv_info *prv;
+
+ prv = xzalloc(struct cbs_priv_info);
+ if ( prv == NULL )
+ return -ENOMEM;
+
+ ops->sched_data = prv;
+ spin_lock_init(&prv->lock);
+
+ return 0;
+}
+
+
+static void cbs_deinit(const struct scheduler *ops)
+{
+ struct cbs_priv_info *prv;
+
+ prv = CBS_PRIV(ops);
+ if ( prv != NULL )
+ xfree(prv);
+}
+
+
+/*
+ * Main scheduling function
+ * Reasons for calling this function are:
+ * -budget for the current server is used up
+ * -vcpu on waitqueue has started it's period
+ * -and various others ;) in general: determine which vcpu to run next
+ */
+static struct task_slice cbs_do_schedule(
+ const struct scheduler *ops, s_time_t now, bool_t tasklet_work_scheduled)
+{
+ int cpu = smp_processor_id();
+ struct list_head *runq = RUNQ(cpu);
+ struct list_head *waitq = WAITQ(cpu);
+ struct cbs_vcpu_info *inf = CBS_VCPU(current);
+ struct cbs_vcpu_info *runinf, *waitinf;
+ struct task_slice ret;
+
+ SCHED_STAT_CRANK(schedule);
+
+ /* Idle tasks don't need any of the following stuff */
+ if ( is_idle_vcpu(current) )
+ goto check_waitq;
+
+ /*
+ * Create local state of the status of the vcpu, in order to avoid
+ * inconsistent state during scheduling decisions, because data for
+ * vcpu_runnable is not protected by the scheduling lock!
+ */
+ if ( !vcpu_runnable(current) )
+ inf->status |= CBS_ASLEEP;
+
+ if ( inf->status & CBS_ASLEEP )
+ inf->block_abs = now;
+
+ desched_edf_vcpu(now, current);
+ check_waitq:
+ update_queues(now, runq, waitq);
+
+ /*
+ * Now simply pick the first vcpu from the runqueue, which has the
+ * earliest deadline, because the list is sorted
+ *
+ * Tasklet work (which runs in idle VCPU context) overrides all else.
+ */
+ if ( tasklet_work_scheduled ||
+ (list_empty(runq) && list_empty(waitq)) ||
+ unlikely(!cpumask_test_cpu(cpu,
+ cpupool_scheduler_cpumask(per_cpu(cpupool, cpu)))) )
+ {
+ ret.task = IDLETASK(cpu);
+ ret.time = SECONDS(1);
+ }
+ else if ( !list_empty(runq) )
+ {
+ runinf = list_entry(runq->next, struct cbs_vcpu_info, list);
+ ret.task = runinf->vcpu;
+ if ( !list_empty(waitq) )
+ {
+ waitinf = list_entry(waitq->next,
+ struct cbs_vcpu_info, list);
+ /*
+ * Rerun scheduler, when scheduled vcpu consumes
+ * its budget or the first vcpu from the waitqueue
+ * gets ready.
+ */
+ ret.time = MIN(now + runinf->budget - runinf->cputime,
+ PERIOD_BEGIN(waitinf)) - now;
+ }
+ else
+ {
+ ret.time = runinf->budget - runinf->cputime;
+ }
+ }
+ else
+ {
+ waitinf = list_entry(waitq->next, struct cbs_vcpu_info, list);
+
+ ret.task = IDLETASK(cpu);
+ ret.time = PERIOD_BEGIN(waitinf) - now;
+ }
+
+ /*
+ * TODO: Do something USEFUL when this happens and find out, why it
+ * still can happen!!!
+ */
+ if ( ret.time < 0)
+ printk("Ouch! We are seriously BEHIND schedule! %"PRIi64"\n",
+ ret.time);
+
+ ret.migrated = 0;
+
+ CBS_VCPU(ret.task)->sched_start_abs = now;
+ CHECK(ret.time > 0);
+ ASSERT(cbs_runnable(ret.task));
+ CBS_PCPU(cpu)->current_budget_expires = now + ret.time;
+ return ret;
+}
+
+static void cbs_sleep(const struct scheduler *ops, struct vcpu *v)
+{
+ if ( is_idle_vcpu(v) )
+ return;
+
+ CBS_VCPU(v)->status |= CBS_ASLEEP;
+
+ if ( per_cpu(schedule_data, v->processor).curr == v )
+ {
+ cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
+ }
+ else
+ {
+ if ( __task_on_queue(v) )
+ __del_from_queue(v);
+ }
+}
+
+/*
+ * Compares two vcpus in the relation of whether the one is allowed to
+ * interrupt the others execution.
+ * It returns true (!=0) if a switch to the other vcpu is good.
+ * Priority scheme is as follows:
+ * EDF: early deadline > late deadline
+ */
+static inline int should_switch(struct vcpu *cur,
+ struct vcpu *other,
+ s_time_t now)
+{
+ struct cbs_vcpu_info *cur_inf, *other_inf;
+ cur_inf = CBS_VCPU(cur);
+ other_inf = CBS_VCPU(other);
+
+ /* Always interrupt idle vcpu. */
+ if ( is_idle_vcpu(cur) )
+ return 1;
+
+ /* Check whether we need to make an earlier scheduling decision */
+ if ( PERIOD_BEGIN(other_inf) <
+ CBS_PCPU(other->processor)->current_budget_expires )
+ return 1;
+
+ return 0;
+}
+
+/*
+ * This function wakes up a vcpu, i.e. moves them into the appropriate queue
+ *
+ * For Hard Real-Time vcpus (soft = 0):
+ * -When a blocked vcpu unblocks, it is allowed to start execution at
+ * the beginning of the next complete period
+ * (D..deadline, R..running, B..blocking/sleeping, U..unblocking/waking up
+ *
+ * DRRB_____D__U_____DRRRRR___D________ ...
+ *
+ * -This causes the vcpu to miss a period (and a deadlline)
+ * -Doesn't disturb the schedule at all
+ * -Deadlines keep occuring isochronous
+ *
+ * For Soft Real-Time vcpus (soft = 1):
+ * -Deadlines are set and updated according to the Constant Bandwidth
Server
+ * rule and vcpus are moved immediately to the run queue.
+ *
+ */
+static void cbs_wake(const struct scheduler *ops, struct vcpu *v)
+{
+ s_time_t now = NOW();
+ struct cbs_vcpu_info* inf = CBS_VCPU(v);
+
+ if ( unlikely(is_idle_vcpu(v)) )
+ return;
+
+ if ( unlikely(__task_on_queue(v)) )
+ return;
+
+ ASSERT(!cbs_runnable(v));
+ inf->status &= ~CBS_ASLEEP;
+
+ if ( unlikely(inf->deadl_abs == 0) )
+ {
+ /* Initial setup of the deadline */
+ inf->deadl_abs = now + inf->budget;
+ }
+
+#ifdef CBS_STATS
+ inf->block_tot++;
+#endif
+
+ if ( cbs_soft(v) )
+ {
+ /* Apply CBS rule
+ * Where:
+ * c == Remaining server budget == (inf->budget - cpu_time)
+ * d == Server (vcpu) deadline == inf->deadl_abs
+ * r == Wake-up time of vcpu == now
+ * U == Server (vcpu) bandwidth == (inf->budget / inf->period)
+ *
+ * if c>=(d-r)*U --->
+ * (inf->budget - cputime) >= (inf->deadl_abs - now) * inf->period
+ *
+ * If true, push deadline back by one period and refresh budget, else
+ * use current budget and deadline.
+ */
+ if((inf->budget - inf->cputime) >=
+ ((inf->deadl_abs - now) * (inf->budget / inf->period)))
+ {
+ /* Push back deadline by one period */
+ inf->deadl_abs += inf->period;
+ inf->cputime = 0;
+ }
+
+ /* In CBS we don't care if the period has begun,
+ * the task doesn't have to wait for its period
+ * because it'll never request more than its budget
+ * for any given period.
+ */
+ __add_to_runqueue_sort(v);
+ }
+ else {
+ /* Task is a hard task, treat accordingly */
+#ifdef CBS_STATS
+ if ( now < inf->deadl_abs )
+ {
+ /* Short blocking */
+ inf->short_block_tot++;
+ }
+ else
+ {
+ /* Long unblocking, someone is going to miss their deadline. */
+ inf->long_block_tot++;
+ }
+#endif
+
+ if ( PERIOD_BEGIN(inf) > now )
+ __add_to_waitqueue_sort(v);
+ else
+ __add_to_runqueue_sort(v);
+ }
+
+#ifdef CBS_STATS
+ /* Do some statistics here... */
+ if ( inf->block_abs != 0 )
+ {
+ inf->block_time_tot += now - inf->block_abs;
+ }
+#endif
+
+ ASSERT(__task_on_queue(v));
+ /*
+ * Check whether the awakened task needs to invoke the do_schedule
+ * routine. Try to avoid unnecessary runs but:
+ * Safe approximation: Always switch to scheduler!
+ */
+ ASSERT(v->processor >= 0);
+ ASSERT(v->processor < nr_cpu_ids);
+ ASSERT(per_cpu(schedule_data, v->processor).curr);
+
+ if ( should_switch(per_cpu(schedule_data, v->processor).curr, v, now) )
+ cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
+}
+
+/* Print a lot of useful information about a vcpus in the system */
+static void cbs_dump_vcpu(struct vcpu *v)
+{
+ printk("%i.%i has=%c ", v->domain->domain_id, v->vcpu_id,
+ v->is_running ? 'T':'F');
+ printk("p=%"PRIu64" sl=%"PRIu64" ddl=%"PRIu64,
+ CBS_VCPU(v)->period, CBS_VCPU(v)->budget, CBS_VCPU(v)->deadl_abs);
+
+#ifdef CBS_STATS
+ printk(" m=%u mt=%"PRIu64"o=%u ot=%"PRIu64,
+ CBS_VCPU(v)->miss_tot, CBS_VCPU(v)->miss_time,
+ CBS_VCPU(v)->over_tot, CBS_VCPU(v)->over_time);
+
+ if ( CBS_VCPU(v)->block_tot != 0 )
+ printk("\n blks=%u sh=%u (%u%%) "\
+ "l=%u (%u%%) avg: b=%"PRIu64,
+ CBS_VCPU(v)->block_tot, CBS_VCPU(v)->short_block_tot,
+ (CBS_VCPU(v)->short_block_tot * 100) / CBS_VCPU(v)->block_tot,
+ CBS_VCPU(v)->long_block_tot,
+ (CBS_VCPU(v)->long_block_tot * 100) / CBS_VCPU(v)->block_tot,
+ (CBS_VCPU(v)->block_time_tot) / CBS_VCPU(v)->block_tot);
+#endif
+ printk("\n");
+}
+
+
+/* Dumps all vcpus on the specified cpu */
+static void cbs_dump_cpu_state(const struct scheduler *ops, int cpu)
+{
+ struct list_head *list, *queue, *tmp;
+ struct cbs_vcpu_info *v_inf;
+ struct domain *d;
+ struct vcpu *v;
+ int loop = 0;
+
+ printk("now=%"PRIu64"\n", NOW());
+ queue = RUNQ(cpu);
+ printk("RUNQ rq %lx n: %lx, p: %lx\n", (unsigned long)queue,
+ (unsigned long) queue->next, (unsigned long) queue->prev);
+ list_for_each_safe ( list, tmp, queue )
+ {
+ printk("%3d: ", loop++);
+ v_inf = list_entry(list, struct cbs_vcpu_info, list);
+ cbs_dump_vcpu(v_inf->vcpu);
+ }
+
+ queue = WAITQ(cpu);
+ loop = 0;
+ printk("\nWAITQ rq %lx n: %lx, p: %lx\n", (unsigned long)queue,
+ (unsigned long) queue->next, (unsigned long) queue->prev);
+ list_for_each_safe ( list, tmp, queue )
+ {
+ printk("%3d: ", loop++);
+ v_inf = list_entry(list, struct cbs_vcpu_info, list);
+ cbs_dump_vcpu(v_inf->vcpu);
+ }
+
+ loop = 0;
+ printk("\nnot on Q\n");
+
+ rcu_read_lock(&domlist_read_lock);
+ for_each_domain ( d )
+ {
+ if ( (d->cpupool ? d->cpupool->sched : &sched_cbs_def) != ops )
+ continue;
+ for_each_vcpu(d, v)
+ {
+ if ( !__task_on_queue(v) && (v->processor == cpu) )
+ {
+ printk("%3d: ", loop++);
+ cbs_dump_vcpu(v);
+ }
+ }
+ }
+ rcu_read_unlock(&domlist_read_lock);
+}
+
+
+/* Set or fetch domain scheduling parameters */
+static int cbs_adjust(const struct scheduler *ops, struct domain *d, struct
xen_domctl_scheduler_op *op)
+{
+ struct cbs_priv_info *prv = CBS_PRIV(ops);
+ unsigned long flags;
+ s_time_t now = NOW();
+ struct vcpu *v;
+ int rc = 0;
+
+ /*
+ * Serialize against the pluggable scheduler lock to protect from
+ * concurrent updates. We need to take the runq lock for the VCPUs
+ * as well, since we are touching budget and period.
+ *
+ * As in sched_credit2.c, runq locks nest inside the pluggable scheduler
+ * lock.
+ */
+ spin_lock_irqsave(&prv->lock, flags);
+
+ if ( op->cmd == XEN_DOMCTL_SCHEDOP_putinfo )
+ {
+ /* Check for sane parameters */
+ if ( !op->u.cbs.period )
+ {
+ printk("Period Not set");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Sanity checking
+ */
+ if ( (op->u.cbs.period > PERIOD_MAX) ||
+ (op->u.cbs.period < PERIOD_MIN) ||
+ (op->u.cbs.budget > op->u.cbs.period) ||
+ (op->u.cbs.budget < BUDGET_MIN) )
+ {
+ printk("Insane Parameters: period: %lu\tbudget: %lu\n",
op->u.cbs.period, op->u.cbs.budget);
+ rc = -EINVAL;
+ goto out;
+ }
+
+ /* Time-driven domains */
+ for_each_vcpu ( d, v )
+ {
+ spinlock_t *lock = vcpu_schedule_lock(v);
+
+ CBS_VCPU(v)->period = op->u.cbs.period;
+ CBS_VCPU(v)->budget = op->u.cbs.budget;
+ if(op->u.cbs.soft)
+ {
+ CBS_VCPU(v)->status |= CBS_SOFT_TASK;
+ }
+ else
+ {
+ /* Correct deadline when switching from a soft to hard vcpu */
+ if( unlikely((CBS_VCPU(v)->deadl_abs - now) >=
(CBS_VCPU(v)->period * 3)) )
+ {
+ CBS_VCPU(v)->deadl_abs = (now - CBS_VCPU(v)->cputime) + (2
* CBS_VCPU(v)->period);
+ }
+
+ CBS_VCPU(v)->status &= (~CBS_SOFT_TASK);
+ }
+ vcpu_schedule_unlock(lock, v);
+ }
+ }
+ else if ( op->cmd == XEN_DOMCTL_SCHEDOP_getinfo )
+ {
+ if ( d->vcpu[0] == NULL )
+ {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ op->u.cbs.period = CBS_VCPU(d->vcpu[0])->period;
+ op->u.cbs.budget = CBS_VCPU(d->vcpu[0])->budget;
+ op->u.cbs.soft = cbs_soft(d->vcpu[0]);
+ }
+
+out:
+ spin_unlock_irqrestore(&prv->lock, flags);
+
+ return rc;
+}
+
+static struct cbs_priv_info _cbs_priv;
+
+const struct scheduler sched_cbs_def = {
+ .name = "Constant Bandwidth Server Scheduler",
+ .opt_name = "cbs",
+ .sched_id = XEN_SCHEDULER_CBS,
+ .sched_data = &_cbs_priv,
+
+ .init_domain = cbs_init_domain,
+ .destroy_domain = cbs_destroy_domain,
+
+ .insert_vcpu = cbs_insert_vcpu,
+
+ .alloc_vdata = cbs_alloc_vdata,
+ .free_vdata = cbs_free_vdata,
+ .alloc_pdata = cbs_alloc_pdata,
+ .free_pdata = cbs_free_pdata,
+ .alloc_domdata = cbs_alloc_domdata,
+ .free_domdata = cbs_free_domdata,
+
+ .init = cbs_init,
+ .deinit = cbs_deinit,
+
+ .do_schedule = cbs_do_schedule,
+ .pick_cpu = cbs_pick_cpu,
+ .dump_cpu_state = cbs_dump_cpu_state,
+ .sleep = cbs_sleep,
+ .wake = cbs_wake,
+ .adjust = cbs_adjust,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/common/sched_sedf.c b/xen/common/sched_sedf.c
deleted file mode 100644
index 5df4825..0000000
--- a/xen/common/sched_sedf.c
+++ /dev/null
@@ -1,917 +0,0 @@
-/******************************************************************************
- * Constant Bandwidth Server Scheduler for Xen
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to
- * deal in the Software without restriction, including without limitation the
- * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
- * sell copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- *
- * by DornerWorks Ltd. (C) 2014 Grand Rapids, MI
- *
- * Adapted from code by Stephan Diestelhorst (C) 2004 Cambridge University
- * and Mark Williamson (C) 2004 Intel Research Cambridge
- *
- */
-
-#include <xen/lib.h>
-#include <xen/sched.h>
-#include <xen/sched-if.h>
-#include <xen/timer.h>
-#include <xen/softirq.h>
-#include <xen/time.h>
-#include <xen/errno.h>
-
-#ifndef NDEBUG
-#define CBS_STATS
-#define CHECK(_p) \
- do { \
- if ( !(_p) ) \
- printk("Check '%s' failed, line %d, file %s\n", \
- #_p , __LINE__, __FILE__); \
- } while ( 0 )
-#else
-#define CHECK(_p) ((void)0)
-#endif
-
-#define CBS_SOFT_TASK (1)
-#define CBS_ASLEEP (16)
-
-#define DEFAULT_PERIOD (MILLISECS(20))
-#define DEFAULT_BUDGET (MILLISECS(10))
-
-#define PERIOD_MAX MILLISECS(10000) /* 10s */
-#define PERIOD_MIN (MICROSECS(10)) /* 10us */
-#define BUDGET_MIN (MICROSECS(5)) /* 5us */
-
-#define EQ(_A, _B) ((!!(_A)) == (!!(_B)))
-
-
-struct cbs_dom_info {
- struct domain *domain;
-};
-
-struct cbs_priv_info {
- /* lock for the whole pluggable scheduler, nests inside cpupool_lock */
- spinlock_t lock;
-};
-
-struct cbs_vcpu_info {
- struct vcpu *vcpu;
- struct list_head list;
-
-
- /* Parameters for EDF-CBS */
- s_time_t period; /* = Server scheduling period */
- s_time_t budget; /* = Guarenteed minimum CPU time per period */
- /* Note: Server bandwidth = (budget / period) */
-
- /* Status of vcpu */
- int status;
- /* Bookkeeping */
- s_time_t deadl_abs;
- s_time_t sched_start_abs;
- s_time_t cputime;
- /* Times the vcpu un-/blocked */
- s_time_t block_abs;
- s_time_t unblock_abs;
-
-#ifdef CBS_STATS
- s_time_t block_time_tot;
- int block_tot;
- int short_block_tot;
- int long_block_tot;
- s_time_t miss_time;
- s_time_t over_time;
- int miss_tot;
- int over_tot;
-#endif
-};
-
-struct cbs_cpu_info {
- struct list_head runnableq;
- struct list_head waitq;
- s_time_t current_budget_expires;
-};
-
-#define CBS_PRIV(_ops) \
- ((struct cbs_priv_info *)((_ops)->sched_data))
-#define CBS_VCPU(_vcpu) ((struct cbs_vcpu_info *)((_vcpu)->sched_priv))
-#define CBS_PCPU(_cpu) \
- ((struct cbs_cpu_info *)per_cpu(schedule_data, _cpu).sched_priv)
-#define LIST(_vcpu) (&CBS_VCPU(_vcpu)->list)
-#define RUNQ(_cpu) (&CBS_PCPU(_cpu)->runnableq)
-#define WAITQ(_cpu) (&CBS_PCPU(_cpu)->waitq)
-#define IDLETASK(_cpu) (idle_vcpu[_cpu])
-
-#define PERIOD_BEGIN(inf) ((inf)->deadl_abs - (inf)->period)
-
-#define DIV_UP(_X, _Y) (((_X) + (_Y) - 1) / _Y)
-
-#define cbs_runnable(edom) (!(CBS_VCPU(edom)->status & CBS_ASLEEP))
-
-#define cbs_soft(edom) (CBS_VCPU(edom)->status & CBS_SOFT_TASK)
-
-static void cbs_dump_cpu_state(const struct scheduler *ops, int cpu);
-
-static inline int __task_on_queue(struct vcpu *v)
-{
- return (((LIST(v))->next != NULL) && (LIST(v)->next != LIST(v)));
-}
-
-static inline void __del_from_queue(struct vcpu *v)
-{
- struct list_head *list = LIST(v);
- ASSERT(__task_on_queue(v));
- list_del(list);
- list->next = NULL;
- ASSERT(!__task_on_queue(v));
-}
-
-typedef int(*list_comparer)(struct list_head* el1, struct list_head* el2);
-
-static inline void list_insert_sort(
- struct list_head *list, struct list_head *element, list_comparer comp)
-{
- struct list_head *cur;
-
- /* Iterate through all elements to find our "hole" */
- list_for_each( cur, list )
- if ( comp(element, cur) < 0 )
- break;
-
- /* cur now contains the element, before which we'll enqueue */
- list_add(element, cur->prev);
-}
-
-#define VCPU_COMPARER(name, field, comp1, comp2) \
-static int name##_comp(struct list_head* el1, struct list_head* el2) \
-{ \
- struct cbs_vcpu_info *v1, *v2; \
- v1 = list_entry(el1, struct cbs_vcpu_info, field); \
- v2 = list_entry(el2, struct cbs_vcpu_info, field); \
- if ( (comp1) == (comp2) ) \
- return 0; \
- if ( (comp1) < (comp2) ) \
- return -1; \
- else \
- return 1; \
-}
-
-/*
- * Adds a vcpu to the queue of processes which wait for the beginning of the
- * next period; this list is therefore sortet by this time, which is simply
- * absol. deadline - period.
- */
-VCPU_COMPARER(waitq, list, PERIOD_BEGIN(v1), PERIOD_BEGIN(v2));
-static inline void __add_to_waitqueue_sort(struct vcpu *v)
-{
- ASSERT(!__task_on_queue(v));
- list_insert_sort(WAITQ(v->processor), LIST(v), waitq_comp);
- ASSERT(__task_on_queue(v));
-}
-
-/*
- * Adds a vcpu to the queue of processes which have started their current
- * period and are runnable (i.e. not blocked, dieing,...). The first element
- * on this list is running on the processor, if the list is empty the idle
- * task will run. As we are implementing EDF, this list is sorted by deadlines.
- */
-VCPU_COMPARER(runq, list, v1->deadl_abs, v2->deadl_abs);
-static inline void __add_to_runqueue_sort(struct vcpu *v)
-{
- list_insert_sort(RUNQ(v->processor), LIST(v), runq_comp);
-}
-
-
-static void cbs_insert_vcpu(const struct scheduler *ops, struct vcpu *v)
-{
- if ( is_idle_vcpu(v) )
- {
- CBS_VCPU(v)->deadl_abs = 0;
- CBS_VCPU(v)->status &= ~CBS_ASLEEP;
- }
-}
-
-static void *cbs_alloc_vdata(const struct scheduler *ops, struct vcpu *v, void
*dd)
-{
- struct cbs_vcpu_info *inf;
-
- inf = xzalloc(struct cbs_vcpu_info);
- if ( inf == NULL )
- return NULL;
-
- inf->vcpu = v;
-
- inf->deadl_abs = 0;
- inf->cputime = 0;
- inf->status = CBS_ASLEEP;
-
- if (v->domain->domain_id == 0)
- {
- /* Domain 0, needs a budget to boot the machine */
- inf->period = DEFAULT_PERIOD;
- inf->budget = DEFAULT_BUDGET;
- }
- else
- {
- inf->period = DEFAULT_PERIOD;
- inf->budget = 0;
- }
-
- INIT_LIST_HEAD(&(inf->list));
-
- SCHED_STAT_CRANK(vcpu_init);
-
- return inf;
-}
-
-static void *
-cbs_alloc_pdata(const struct scheduler *ops, int cpu)
-{
- struct cbs_cpu_info *spc;
-
- spc = xzalloc(struct cbs_cpu_info);
- BUG_ON(spc == NULL);
- INIT_LIST_HEAD(&spc->waitq);
- INIT_LIST_HEAD(&spc->runnableq);
-
- return (void *)spc;
-}
-
-static void
-cbs_free_pdata(const struct scheduler *ops, void *spc, int cpu)
-{
- if ( spc == NULL )
- return;
-
- xfree(spc);
-}
-
-static void cbs_free_vdata(const struct scheduler *ops, void *priv)
-{
- xfree(priv);
-}
-
-static void *
-cbs_alloc_domdata(const struct scheduler *ops, struct domain *d)
-{
- return xzalloc(struct cbs_dom_info);
-}
-
-static int cbs_init_domain(const struct scheduler *ops, struct domain *d)
-{
- d->sched_priv = cbs_alloc_domdata(ops, d);
- if ( d->sched_priv == NULL )
- return -ENOMEM;
-
- return 0;
-}
-
-static void cbs_free_domdata(const struct scheduler *ops, void *data)
-{
- xfree(data);
-}
-
-static void cbs_destroy_domain(const struct scheduler *ops, struct domain *d)
-{
- cbs_free_domdata(ops, d->sched_priv);
-}
-
-static int cbs_pick_cpu(const struct scheduler *ops, struct vcpu *v)
-{
- cpumask_t online_affinity;
- cpumask_t *online;
-
- online = cpupool_scheduler_cpumask(v->domain->cpupool);
- cpumask_and(&online_affinity, v->cpu_affinity, online);
- return cpumask_cycle(v->vcpu_id % cpumask_weight(&online_affinity) - 1,
- &online_affinity);
-}
-
-/*
- * Handles the rescheduling & bookkeeping of vcpus running in their
- * guaranteed time budget.
- */
-static void desched_edf_vcpu(s_time_t now, struct vcpu *v)
-{
- struct cbs_vcpu_info* inf = CBS_VCPU(v);
-
- /* Current vcpu is running in real time mode */
- ASSERT(__task_on_queue(v));
-
- /* Update the vcpu's cputime */
- inf->cputime += now - inf->sched_start_abs;
-
- /* Scheduling decisions which don't remove the running vcpu from
- * the runq */
- if ( (inf->cputime < inf->budget) && cbs_runnable(v) )
- return;
-
- __del_from_queue(v);
-
-#ifdef CBS_STATS
- /* Manage deadline misses */
- if ( unlikely(inf->deadl_abs < now) )
- {
- inf->miss_tot++;
- inf->miss_time += inf->cputime;
- }
-#endif
-
- /* Manage overruns */
- if ( inf->cputime >= inf->budget )
- {
- inf->cputime -= inf->budget;
-
-
- /* Set next deadline */
- inf->deadl_abs += inf->period;
-
- /* Ensure that the cputime is always less than budget */
- if ( unlikely(inf->cputime > inf->budget) )
- {
-#ifdef CBS_STATS
- inf->over_tot++;
- inf->over_time += inf->cputime;
-#endif
-
- /* Make up for the overage by pushing the deadline
- into the future */
- inf->deadl_abs += ((inf->cputime / inf->budget)
- * inf->period) * 2;
- inf->cputime -= (inf->cputime / inf->budget) * inf->budget;
- }
-
- /* Ensure that the start of the next period is in the future */
- if ( unlikely(PERIOD_BEGIN(inf) < now) )
- inf->deadl_abs +=
- (DIV_UP(now - PERIOD_BEGIN(inf),
- inf->period)) * inf->period;
- }
-
- /* Add a runnable vcpu to the appropriate queue */
- if ( cbs_runnable(v) )
- {
- if( cbs_soft(v) )
- {
- __add_to_runqueue_sort(v);
- }
- else
- {
- __add_to_waitqueue_sort(v);
- }
- }
-
- ASSERT(EQ(cbs_runnable(v), __task_on_queue(v)));
-}
-
-
-/* Update all elements on the queues */
-static void update_queues(
- s_time_t now, struct list_head *runq, struct list_head *waitq)
-{
- struct list_head *cur, *tmp;
- struct cbs_vcpu_info *curinf;
-
- /*
- * Check for the first elements of the waitqueue, whether their
- * next period has already started.
- */
- list_for_each_safe ( cur, tmp, waitq )
- {
- curinf = list_entry(cur, struct cbs_vcpu_info, list);
- if ( PERIOD_BEGIN(curinf) > now )
- break;
- __del_from_queue(curinf->vcpu);
- __add_to_runqueue_sort(curinf->vcpu);
- }
-
- /* Process the runq, find vcpus that are on the runq that shouldn't */
- list_for_each_safe ( cur, tmp, runq )
- {
- curinf = list_entry(cur, struct cbs_vcpu_info, list);
-
- if ( unlikely(curinf->budget == 0) )
- {
- /* Ignore vcpus with empty budget */
- __del_from_queue(curinf->vcpu);
-
- /* Move them to their next period */
- curinf->deadl_abs += curinf->period;
-
- /* Ensure that the start of the next period is in the future */
- if ( unlikely(PERIOD_BEGIN(curinf) < now) )
- curinf->deadl_abs +=
- (DIV_UP(now - PERIOD_BEGIN(curinf),
- curinf->period)) * curinf->period;
-
- /* Put them back into the queue */
- __add_to_waitqueue_sort(curinf->vcpu);
- }
-
- else
- break;
- }
-}
-
-
-static int cbs_init(struct scheduler *ops)
-{
- struct cbs_priv_info *prv;
-
- prv = xzalloc(struct cbs_priv_info);
- if ( prv == NULL )
- return -ENOMEM;
-
- ops->sched_data = prv;
- spin_lock_init(&prv->lock);
-
- return 0;
-}
-
-
-static void cbs_deinit(const struct scheduler *ops)
-{
- struct cbs_priv_info *prv;
-
- prv = CBS_PRIV(ops);
- if ( prv != NULL )
- xfree(prv);
-}
-
-
-/*
- * Main scheduling function
- * Reasons for calling this function are:
- * -budget for the current server is used up
- * -vcpu on waitqueue has started it's period
- * -and various others ;) in general: determine which vcpu to run next
- */
-static struct task_slice cbs_do_schedule(
- const struct scheduler *ops, s_time_t now, bool_t tasklet_work_scheduled)
-{
- int cpu = smp_processor_id();
- struct list_head *runq = RUNQ(cpu);
- struct list_head *waitq = WAITQ(cpu);
- struct cbs_vcpu_info *inf = CBS_VCPU(current);
- struct cbs_vcpu_info *runinf, *waitinf;
- struct task_slice ret;
-
- SCHED_STAT_CRANK(schedule);
-
- /* Idle tasks don't need any of the following stuff */
- if ( is_idle_vcpu(current) )
- goto check_waitq;
-
- /*
- * Create local state of the status of the vcpu, in order to avoid
- * inconsistent state during scheduling decisions, because data for
- * vcpu_runnable is not protected by the scheduling lock!
- */
- if ( !vcpu_runnable(current) )
- inf->status |= CBS_ASLEEP;
-
- if ( inf->status & CBS_ASLEEP )
- inf->block_abs = now;
-
- desched_edf_vcpu(now, current);
- check_waitq:
- update_queues(now, runq, waitq);
-
- /*
- * Now simply pick the first vcpu from the runqueue, which has the
- * earliest deadline, because the list is sorted
- *
- * Tasklet work (which runs in idle VCPU context) overrides all else.
- */
- if ( tasklet_work_scheduled ||
- (list_empty(runq) && list_empty(waitq)) ||
- unlikely(!cpumask_test_cpu(cpu,
- cpupool_scheduler_cpumask(per_cpu(cpupool, cpu)))) )
- {
- ret.task = IDLETASK(cpu);
- ret.time = SECONDS(1);
- }
- else if ( !list_empty(runq) )
- {
- runinf = list_entry(runq->next, struct cbs_vcpu_info, list);
- ret.task = runinf->vcpu;
- if ( !list_empty(waitq) )
- {
- waitinf = list_entry(waitq->next,
- struct cbs_vcpu_info, list);
- /*
- * Rerun scheduler, when scheduled vcpu consumes
- * its budget or the first vcpu from the waitqueue
- * gets ready.
- */
- ret.time = MIN(now + runinf->budget - runinf->cputime,
- PERIOD_BEGIN(waitinf)) - now;
- }
- else
- {
- ret.time = runinf->budget - runinf->cputime;
- }
- }
- else
- {
- waitinf = list_entry(waitq->next, struct cbs_vcpu_info, list);
-
- ret.task = IDLETASK(cpu);
- ret.time = PERIOD_BEGIN(waitinf) - now;
- }
-
- /*
- * TODO: Do something USEFUL when this happens and find out, why it
- * still can happen!!!
- */
- if ( ret.time < 0)
- printk("Ouch! We are seriously BEHIND schedule! %"PRIi64"\n",
- ret.time);
-
- ret.migrated = 0;
-
- CBS_VCPU(ret.task)->sched_start_abs = now;
- CHECK(ret.time > 0);
- ASSERT(cbs_runnable(ret.task));
- CBS_PCPU(cpu)->current_budget_expires = now + ret.time;
- return ret;
-}
-
-static void cbs_sleep(const struct scheduler *ops, struct vcpu *v)
-{
- if ( is_idle_vcpu(v) )
- return;
-
- CBS_VCPU(v)->status |= CBS_ASLEEP;
-
- if ( per_cpu(schedule_data, v->processor).curr == v )
- {
- cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
- }
- else
- {
- if ( __task_on_queue(v) )
- __del_from_queue(v);
- }
-}
-
-/*
- * Compares two vcpus in the relation of whether the one is allowed to
- * interrupt the others execution.
- * It returns true (!=0) if a switch to the other vcpu is good.
- * Priority scheme is as follows:
- * EDF: early deadline > late deadline
- */
-static inline int should_switch(struct vcpu *cur,
- struct vcpu *other,
- s_time_t now)
-{
- struct cbs_vcpu_info *cur_inf, *other_inf;
- cur_inf = CBS_VCPU(cur);
- other_inf = CBS_VCPU(other);
-
- /* Always interrupt idle vcpu. */
- if ( is_idle_vcpu(cur) )
- return 1;
-
- /* Check whether we need to make an earlier scheduling decision */
- if ( PERIOD_BEGIN(other_inf) <
- CBS_PCPU(other->processor)->current_budget_expires )
- return 1;
-
- return 0;
-}
-
-/*
- * This function wakes up a vcpu, i.e. moves them into the appropriate queue
- *
- * For Hard Real-Time vcpus (soft = 0):
- * -When a blocked vcpu unblocks, it is allowed to start execution at
- * the beginning of the next complete period
- * (D..deadline, R..running, B..blocking/sleeping, U..unblocking/waking up
- *
- * DRRB_____D__U_____DRRRRR___D________ ...
- *
- * -This causes the vcpu to miss a period (and a deadlline)
- * -Doesn't disturb the schedule at all
- * -Deadlines keep occuring isochronous
- *
- * For Soft Real-Time vcpus (soft = 1):
- * -Deadlines are set and updated according to the Constant Bandwidth
Server
- * rule and vcpus are moved immediately to the run queue.
- *
- */
-static void cbs_wake(const struct scheduler *ops, struct vcpu *v)
-{
- s_time_t now = NOW();
- struct cbs_vcpu_info* inf = CBS_VCPU(v);
-
- if ( unlikely(is_idle_vcpu(v)) )
- return;
-
- if ( unlikely(__task_on_queue(v)) )
- return;
-
- ASSERT(!cbs_runnable(v));
- inf->status &= ~CBS_ASLEEP;
-
- if ( unlikely(inf->deadl_abs == 0) )
- {
- /* Initial setup of the deadline */
- inf->deadl_abs = now + inf->budget;
- }
-
-#ifdef CBS_STATS
- inf->block_tot++;
-#endif
-
- if ( cbs_soft(v) )
- {
- /* Apply CBS rule
- * Where:
- * c == Remaining server budget == (inf->budget - cpu_time)
- * d == Server (vcpu) deadline == inf->deadl_abs
- * r == Wake-up time of vcpu == now
- * U == Server (vcpu) bandwidth == (inf->budget / inf->period)
- *
- * if c>=(d-r)*U --->
- * (inf->budget - cputime) >= (inf->deadl_abs - now) * inf->period
- *
- * If true, push deadline back by one period and refresh budget, else
- * use current budget and deadline.
- */
- if((inf->budget - inf->cputime) >=
- ((inf->deadl_abs - now) * (inf->budget / inf->period)))
- {
- /* Push back deadline by one period */
- inf->deadl_abs += inf->period;
- inf->cputime = 0;
- }
-
- /* In CBS we don't care if the period has begun,
- * the task doesn't have to wait for its period
- * because it'll never request more than its budget
- * for any given period.
- */
- __add_to_runqueue_sort(v);
- }
- else {
- /* Task is a hard task, treat accordingly */
-#ifdef CBS_STATS
- if ( now < inf->deadl_abs )
- {
- /* Short blocking */
- inf->short_block_tot++;
- }
- else
- {
- /* Long unblocking, someone is going to miss their deadline. */
- inf->long_block_tot++;
- }
-#endif
-
- if ( PERIOD_BEGIN(inf) > now )
- __add_to_waitqueue_sort(v);
- else
- __add_to_runqueue_sort(v);
- }
-
-#ifdef CBS_STATS
- /* Do some statistics here... */
- if ( inf->block_abs != 0 )
- {
- inf->block_time_tot += now - inf->block_abs;
- }
-#endif
-
- ASSERT(__task_on_queue(v));
- /*
- * Check whether the awakened task needs to invoke the do_schedule
- * routine. Try to avoid unnecessary runs but:
- * Safe approximation: Always switch to scheduler!
- */
- ASSERT(v->processor >= 0);
- ASSERT(v->processor < nr_cpu_ids);
- ASSERT(per_cpu(schedule_data, v->processor).curr);
-
- if ( should_switch(per_cpu(schedule_data, v->processor).curr, v, now) )
- cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
-}
-
-/* Print a lot of useful information about a vcpus in the system */
-static void cbs_dump_vcpu(struct vcpu *v)
-{
- printk("%i.%i has=%c ", v->domain->domain_id, v->vcpu_id,
- v->is_running ? 'T':'F');
- printk("p=%"PRIu64" sl=%"PRIu64" ddl=%"PRIu64,
- CBS_VCPU(v)->period, CBS_VCPU(v)->budget, CBS_VCPU(v)->deadl_abs);
-
-#ifdef CBS_STATS
- printk(" m=%u mt=%"PRIu64"o=%u ot=%"PRIu64,
- CBS_VCPU(v)->miss_tot, CBS_VCPU(v)->miss_time,
- CBS_VCPU(v)->over_tot, CBS_VCPU(v)->over_time);
-
- if ( CBS_VCPU(v)->block_tot != 0 )
- printk("\n blks=%u sh=%u (%u%%) "\
- "l=%u (%u%%) avg: b=%"PRIu64,
- CBS_VCPU(v)->block_tot, CBS_VCPU(v)->short_block_tot,
- (CBS_VCPU(v)->short_block_tot * 100) / CBS_VCPU(v)->block_tot,
- CBS_VCPU(v)->long_block_tot,
- (CBS_VCPU(v)->long_block_tot * 100) / CBS_VCPU(v)->block_tot,
- (CBS_VCPU(v)->block_time_tot) / CBS_VCPU(v)->block_tot);
-#endif
- printk("\n");
-}
-
-
-/* Dumps all vcpus on the specified cpu */
-static void cbs_dump_cpu_state(const struct scheduler *ops, int cpu)
-{
- struct list_head *list, *queue, *tmp;
- struct cbs_vcpu_info *v_inf;
- struct domain *d;
- struct vcpu *v;
- int loop = 0;
-
- printk("now=%"PRIu64"\n", NOW());
- queue = RUNQ(cpu);
- printk("RUNQ rq %lx n: %lx, p: %lx\n", (unsigned long)queue,
- (unsigned long) queue->next, (unsigned long) queue->prev);
- list_for_each_safe ( list, tmp, queue )
- {
- printk("%3d: ", loop++);
- v_inf = list_entry(list, struct cbs_vcpu_info, list);
- cbs_dump_vcpu(v_inf->vcpu);
- }
-
- queue = WAITQ(cpu);
- loop = 0;
- printk("\nWAITQ rq %lx n: %lx, p: %lx\n", (unsigned long)queue,
- (unsigned long) queue->next, (unsigned long) queue->prev);
- list_for_each_safe ( list, tmp, queue )
- {
- printk("%3d: ", loop++);
- v_inf = list_entry(list, struct cbs_vcpu_info, list);
- cbs_dump_vcpu(v_inf->vcpu);
- }
-
- loop = 0;
- printk("\nnot on Q\n");
-
- rcu_read_lock(&domlist_read_lock);
- for_each_domain ( d )
- {
- if ( (d->cpupool ? d->cpupool->sched : &sched_cbs_def) != ops )
- continue;
- for_each_vcpu(d, v)
- {
- if ( !__task_on_queue(v) && (v->processor == cpu) )
- {
- printk("%3d: ", loop++);
- cbs_dump_vcpu(v);
- }
- }
- }
- rcu_read_unlock(&domlist_read_lock);
-}
-
-
-/* Set or fetch domain scheduling parameters */
-static int cbs_adjust(const struct scheduler *ops, struct domain *d, struct
xen_domctl_scheduler_op *op)
-{
- struct cbs_priv_info *prv = CBS_PRIV(ops);
- unsigned long flags;
- s_time_t now = NOW();
- struct vcpu *v;
- int rc = 0;
-
- /*
- * Serialize against the pluggable scheduler lock to protect from
- * concurrent updates. We need to take the runq lock for the VCPUs
- * as well, since we are touching budget and period.
- *
- * As in sched_credit2.c, runq locks nest inside the pluggable scheduler
- * lock.
- */
- spin_lock_irqsave(&prv->lock, flags);
-
- if ( op->cmd == XEN_DOMCTL_SCHEDOP_putinfo )
- {
- /* Check for sane parameters */
- if ( !op->u.cbs.period )
- {
- printk("Period Not set");
- rc = -EINVAL;
- goto out;
- }
-
- /*
- * Sanity checking
- */
- if ( (op->u.cbs.period > PERIOD_MAX) ||
- (op->u.cbs.period < PERIOD_MIN) ||
- (op->u.cbs.budget > op->u.cbs.period) ||
- (op->u.cbs.budget < BUDGET_MIN) )
- {
- printk("Insane Parameters: period: %lu\tbudget: %lu\n",
op->u.cbs.period, op->u.cbs.budget);
- rc = -EINVAL;
- goto out;
- }
-
- /* Time-driven domains */
- for_each_vcpu ( d, v )
- {
- spinlock_t *lock = vcpu_schedule_lock(v);
-
- CBS_VCPU(v)->period = op->u.cbs.period;
- CBS_VCPU(v)->budget = op->u.cbs.budget;
- if(op->u.cbs.soft)
- {
- CBS_VCPU(v)->status |= CBS_SOFT_TASK;
- }
- else
- {
- /* Correct deadline when switching from a soft to hard vcpu */
- if( unlikely((CBS_VCPU(v)->deadl_abs - now) >=
(CBS_VCPU(v)->period * 3)) )
- {
- CBS_VCPU(v)->deadl_abs = (now - CBS_VCPU(v)->cputime) + (2
* CBS_VCPU(v)->period);
- }
-
- CBS_VCPU(v)->status &= (~CBS_SOFT_TASK);
- }
- vcpu_schedule_unlock(lock, v);
- }
- }
- else if ( op->cmd == XEN_DOMCTL_SCHEDOP_getinfo )
- {
- if ( d->vcpu[0] == NULL )
- {
- rc = -EINVAL;
- goto out;
- }
-
- op->u.cbs.period = CBS_VCPU(d->vcpu[0])->period;
- op->u.cbs.budget = CBS_VCPU(d->vcpu[0])->budget;
- op->u.cbs.soft = cbs_soft(d->vcpu[0]);
- }
-
-out:
- spin_unlock_irqrestore(&prv->lock, flags);
-
- return rc;
-}
-
-static struct cbs_priv_info _cbs_priv;
-
-const struct scheduler sched_cbs_def = {
- .name = "Constant Bandwidth Server Scheduler",
- .opt_name = "cbs",
- .sched_id = XEN_SCHEDULER_CBS,
- .sched_data = &_cbs_priv,
-
- .init_domain = cbs_init_domain,
- .destroy_domain = cbs_destroy_domain,
-
- .insert_vcpu = cbs_insert_vcpu,
-
- .alloc_vdata = cbs_alloc_vdata,
- .free_vdata = cbs_free_vdata,
- .alloc_pdata = cbs_alloc_pdata,
- .free_pdata = cbs_free_pdata,
- .alloc_domdata = cbs_alloc_domdata,
- .free_domdata = cbs_free_domdata,
-
- .init = cbs_init,
- .deinit = cbs_deinit,
-
- .do_schedule = cbs_do_schedule,
- .pick_cpu = cbs_pick_cpu,
- .dump_cpu_state = cbs_dump_cpu_state,
- .sleep = cbs_sleep,
- .wake = cbs_wake,
- .adjust = cbs_adjust,
-};
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * indent-tabs-mode: nil
- * End:
- */
--
1.7.9.5
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