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From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: "Juergen Gross" <jgross@suse.com>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Wei Liu" <wl@xen.org>,
	"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
	"George Dunlap" <George.Dunlap@eu.citrix.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Ian Jackson" <ian.jackson@eu.citrix.com>,
	"Tim Deegan" <tim@xen.org>, "Julien Grall" <julien.grall@arm.com>,
	"Jan Beulich" <jbeulich@suse.com>,
	"Dario Faggioli" <dfaggioli@suse.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH v2 48/48] xen/sched: add scheduling granularity enum
Date: Fri,  9 Aug 2019 16:58:33 +0200
Message-ID: <20190809145833.1020-49-jgross@suse.com> (raw)
In-Reply-To: <20190809145833.1020-1-jgross@suse.com>

Add a scheduling granularity enum ("cpu", "core", "socket") for
specification of the scheduling granularity. Initially it is set to
"cpu", this can be modified by the new boot parameter (x86 only)
"sched-gran".

According to the selected granularity sched_granularity is set after
all cpus are online.

A test is added for all sched resources holding the same number of
cpus. Fall back to core- or cpu-scheduling in that case.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
RFC V2:
- fixed freeing of sched_res when merging cpus
- rename parameter to "sched-gran" (Jan Beulich)
- rename parameter option from "thread" to "cpu" (Jan Beulich)

V1:
- rename scheduler_smp_init() to scheduler_gran_init(), let it be called
  by cpupool_init()
- avoid using literal cpu number 0 in scheduler_percpu_init() (Jan Beulich)
- style correction (Jan Beulich)
- fallback to smaller granularity instead of panic in case of
  unbalanced cpu configuration

V2:
- style changes (Jan Beulich)
- introduce CONFIG_HAS_SCHED_GRANULARITY (Jan Beulich)
---
 xen/arch/x86/Kconfig       |  1 +
 xen/common/Kconfig         |  3 ++
 xen/common/cpupool.c       |  2 ++
 xen/common/schedule.c      | 78 ++++++++++++++++++++++++++++++++++++++++++++++
 xen/include/xen/sched-if.h |  1 +
 5 files changed, 85 insertions(+)

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 288dc6c042..3f88adae97 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -22,6 +22,7 @@ config X86
 	select HAS_PASSTHROUGH
 	select HAS_PCI
 	select HAS_PDX
+	select HAS_SCHED_GRANULARITY
 	select HAS_UBSAN
 	select HAS_VPCI if !PV_SHIM_EXCLUSIVE && HVM
 	select NEEDS_LIBELF
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 16829f6274..e9247871a8 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -63,6 +63,9 @@ config HAS_GDBSX
 config HAS_IOPORTS
 	bool
 
+config HAS_SCHED_GRANULARITY
+	bool
+
 config NEEDS_LIBELF
 	bool
 
diff --git a/xen/common/cpupool.c b/xen/common/cpupool.c
index 6917488210..d12269d5a3 100644
--- a/xen/common/cpupool.c
+++ b/xen/common/cpupool.c
@@ -870,6 +870,8 @@ static int __init cpupool_init(void)
     unsigned int cpu;
     int err;
 
+    scheduler_gran_init();
+
     cpupool0 = cpupool_create(0, 0, &err);
     BUG_ON(cpupool0 == NULL);
     cpupool_put(cpupool0);
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 181adb00b2..bd596ba1dc 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -34,6 +34,7 @@
 #include <xen/cpu.h>
 #include <xen/preempt.h>
 #include <xen/event.h>
+#include <xen/warning.h>
 #include <public/sched.h>
 #include <xsm/xsm.h>
 #include <xen/err.h>
@@ -61,6 +62,23 @@ unsigned int __read_mostly sched_granularity = 1;
 bool __read_mostly sched_disable_smt_switching;
 cpumask_var_t sched_res_mask;
 
+#ifdef CONFIG_HAS_SCHED_GRANULARITY
+static int __init sched_select_granularity(const char *str)
+{
+    if ( strcmp("cpu", str) == 0 )
+        opt_sched_granularity = SCHED_GRAN_cpu;
+    else if ( strcmp("core", str) == 0 )
+        opt_sched_granularity = SCHED_GRAN_core;
+    else if ( strcmp("socket", str) == 0 )
+        opt_sched_granularity = SCHED_GRAN_socket;
+    else
+        return -EINVAL;
+
+    return 0;
+}
+custom_param("sched-gran", sched_select_granularity);
+#endif
+
 /* Common lock for free cpus. */
 static DEFINE_SPINLOCK(sched_free_cpu_lock);
 
@@ -2606,6 +2624,66 @@ void scheduler_enable(void)
     scheduler_active = true;
 }
 
+static unsigned int __init sched_check_granularity(void)
+{
+    unsigned int cpu;
+    unsigned int siblings, gran = 0;
+
+    if ( opt_sched_granularity == SCHED_GRAN_cpu )
+        return 1;
+
+    for_each_online_cpu ( cpu )
+    {
+        siblings = cpumask_weight(sched_get_opt_cpumask(opt_sched_granularity,
+                                                        cpu));
+        if ( gran == 0 )
+            gran = siblings;
+        else if ( gran != siblings )
+            return 0;
+    }
+
+    sched_disable_smt_switching = true;
+
+    return gran;
+}
+
+/* Setup data for selected scheduler granularity. */
+void __init scheduler_gran_init(void)
+{
+    unsigned int gran = 0;
+    const char *fallback = NULL;
+
+    while ( gran == 0 )
+    {
+        gran = sched_check_granularity();
+
+        if ( gran == 0 )
+        {
+            switch ( opt_sched_granularity )
+            {
+            case SCHED_GRAN_core:
+                opt_sched_granularity = SCHED_GRAN_cpu;
+                fallback = "Asymmetric cpu configuration.\n"
+                           "Falling back to sched-gran=cpu.\n";
+                break;
+            case SCHED_GRAN_socket:
+                opt_sched_granularity = SCHED_GRAN_core;
+                fallback = "Asymmetric cpu configuration.\n"
+                           "Falling back to sched-gran=core.\n";
+                break;
+            default:
+                ASSERT_UNREACHABLE();
+                break;
+            }
+        }
+    }
+
+    if ( fallback )
+        warning_add(fallback);
+
+    sched_granularity = gran;
+}
+
 /* Initialise the data structures. */
 void __init scheduler_init(void)
 {
diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index c152547a94..ace08d609c 100644
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -625,5 +625,6 @@ affinity_balance_cpumask(const struct sched_unit *unit, int step,
 
 void sched_rm_cpu(unsigned int cpu);
 const cpumask_t *sched_get_opt_cpumask(enum sched_gran opt, unsigned int cpu);
+void scheduler_gran_init(void);
 
 #endif /* __XEN_SCHED_IF_H__ */
-- 
2.16.4


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  parent reply index

Thread overview: 126+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-09 14:57 [Xen-devel] [PATCH v2 00/48] xen: add core scheduling support Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 01/48] xen/sched: use new sched_unit instead of vcpu in scheduler interfaces Juergen Gross
2019-09-02  9:07   ` Jan Beulich
2019-09-09  5:26     ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 02/48] xen/sched: move per-vcpu scheduler private data pointer to sched_unit Juergen Gross
2019-08-23 10:47   ` Dario Faggioli
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 03/48] xen/sched: build a linked list of struct sched_unit Juergen Gross
2019-08-23 10:52   ` Dario Faggioli
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 04/48] xen/sched: introduce struct sched_resource Juergen Gross
2019-08-23 10:54   ` Dario Faggioli
2019-09-04 13:10   ` Jan Beulich
2019-09-09  5:31     ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 05/48] xen/sched: let pick_cpu return a scheduler resource Juergen Gross
2019-09-04 13:34   ` Jan Beulich
2019-09-09  5:43     ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 06/48] xen/sched: switch schedule_data.curr to point at sched_unit Juergen Gross
2019-09-04 13:36   ` Jan Beulich
2019-09-09  5:46     ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 07/48] xen/sched: move per cpu scheduler private data into struct sched_resource Juergen Gross
2019-09-04 13:48   ` Jan Beulich
2019-09-05  7:13     ` Juergen Gross
2019-09-05  7:38       ` Jan Beulich
2019-09-09 13:03         ` Dario Faggioli
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 08/48] xen/sched: switch vcpu_schedule_lock to unit_schedule_lock Juergen Gross
2019-09-04 14:02   ` Jan Beulich
2019-09-04 14:41     ` Juergen Gross
2019-09-04 14:54       ` Jan Beulich
2019-09-04 15:02         ` Juergen Gross
2019-09-11 16:02           ` Dario Faggioli
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 09/48] xen/sched: move some per-vcpu items to struct sched_unit Juergen Gross
2019-09-04 14:16   ` Jan Beulich
2019-09-09  6:39     ` Juergen Gross
2019-09-09  6:55       ` Jan Beulich
2019-09-09  7:05         ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 10/48] xen/sched: add scheduler helpers hiding vcpu Juergen Gross
2019-09-04 14:49   ` Jan Beulich
2019-09-11 13:22     ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 11/48] xen/sched: rename scheduler related perf counters Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 12/48] xen/sched: switch struct task_slice from vcpu to sched_unit Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 13/48] xen/sched: add is_running indicator to struct sched_unit Juergen Gross
2019-09-04 15:06   ` Jan Beulich
2019-09-11 13:44     ` Juergen Gross
2019-09-11 15:06       ` Jan Beulich
2019-09-11 15:32         ` Juergen Gross
2019-08-09 14:57 ` [Xen-devel] [PATCH v2 14/48] xen/sched: make null scheduler vcpu agnostic Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 15/48] xen/sched: make rt " Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 16/48] xen/sched: make credit " Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 17/48] xen/sched: make credit2 " Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 18/48] xen/sched: make arinc653 " Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 19/48] xen: add sched_unit_pause_nosync() and sched_unit_unpause() Juergen Gross
2019-09-09 13:34   ` Jan Beulich
2019-09-11 14:15     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 20/48] xen: let vcpu_create() select processor Juergen Gross
2019-08-23 16:42   ` Julien Grall
2019-09-09 13:38   ` Jan Beulich
2019-09-11 14:22     ` Juergen Gross
2019-09-11 17:20       ` Dario Faggioli
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 21/48] xen/sched: use sched_resource cpu instead smp_processor_id in schedulers Juergen Gross
2019-09-09 14:17   ` Jan Beulich
2019-09-12  9:34     ` Juergen Gross
2019-09-12 10:04       ` Jan Beulich
2019-09-12 11:03         ` Juergen Gross
2019-09-12 11:17         ` Juergen Gross
2019-09-12 11:46           ` Jan Beulich
2019-09-12 11:53             ` Juergen Gross
2019-09-12 12:08               ` Jan Beulich
2019-09-12 12:13                 ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 22/48] xen/sched: switch schedule() from vcpus to sched_units Juergen Gross
2019-09-09 14:35   ` Jan Beulich
2019-09-12 13:44     ` Juergen Gross
2019-09-12 14:34       ` Jan Beulich
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 23/48] xen/sched: switch sched_move_irqs() to take sched_unit as parameter Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 24/48] xen: switch from for_each_vcpu() to for_each_sched_unit() Juergen Gross
2019-09-09 15:14   ` Jan Beulich
2019-09-12 14:02     ` Juergen Gross
2019-09-12 14:40       ` Jan Beulich
2019-09-12 14:47         ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 25/48] xen/sched: add runstate counters to struct sched_unit Juergen Gross
2019-09-09 14:30   ` Jan Beulich
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 26/48] xen/sched: rework and rename vcpu_force_reschedule() Juergen Gross
2019-09-10 14:06   ` Jan Beulich
2019-09-13  9:33     ` Juergen Gross
2019-09-13  9:40       ` Jan Beulich
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 27/48] xen/sched: Change vcpu_migrate_*() to operate on schedule unit Juergen Gross
2019-09-10 15:11   ` Jan Beulich
2019-09-13 12:33     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 28/48] xen/sched: move struct task_slice into struct sched_unit Juergen Gross
2019-09-10 15:18   ` Jan Beulich
2019-09-13 12:56     ` Juergen Gross
2019-09-12  8:13   ` Dario Faggioli
2019-09-12  8:21     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 29/48] xen/sched: add code to sync scheduling of all vcpus of a sched unit Juergen Gross
2019-09-10 15:36   ` Jan Beulich
2019-09-13 13:12     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 30/48] xen/sched: introduce unit_runnable_state() Juergen Gross
2019-09-11 10:30   ` Jan Beulich
2019-09-12 10:22     ` Dario Faggioli
2019-09-13 14:07     ` Juergen Gross
2019-09-13 14:44       ` Jan Beulich
2019-09-13 15:23         ` Juergen Gross
2019-09-12 10:24   ` Dario Faggioli
2019-09-13 14:14     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 31/48] xen/sched: add support for multiple vcpus per sched unit where missing Juergen Gross
2019-09-11 10:43   ` Jan Beulich
2019-09-13 15:01     ` Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 32/48] xen/sched: modify cpupool_domain_cpumask() to be an unit mask Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 33/48] xen/sched: support allocating multiple vcpus into one sched unit Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 34/48] xen/sched: add a percpu resource index Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 35/48] xen/sched: add fall back to idle vcpu when scheduling unit Juergen Gross
2019-09-11 11:33   ` Julien Grall
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 36/48] xen/sched: make vcpu_wake() and vcpu_sleep() core scheduling aware Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 37/48] xen/sched: carve out freeing sched_unit memory into dedicated function Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 38/48] xen/sched: move per-cpu variable scheduler to struct sched_resource Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 39/48] xen/sched: move per-cpu variable cpupool " Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 40/48] xen/sched: reject switching smt on/off with core scheduling active Juergen Gross
2019-09-10 15:47   ` Jan Beulich
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 41/48] xen/sched: prepare per-cpupool scheduling granularity Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 42/48] xen/sched: split schedule_cpu_switch() Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 43/48] xen/sched: protect scheduling resource via rcu Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 44/48] xen/sched: support multiple cpus per scheduling resource Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 45/48] xen/sched: support differing granularity in schedule_cpu_[add/rm]() Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 46/48] xen/sched: support core scheduling for moving cpus to/from cpupools Juergen Gross
2019-08-09 14:58 ` [Xen-devel] [PATCH v2 47/48] xen/sched: disable scheduling when entering ACPI deep sleep states Juergen Gross
2019-08-09 14:58 ` Juergen Gross [this message]
2019-08-15 10:17 ` [Xen-devel] [PATCH v2 00/48] xen: add core scheduling support Sergey Dyasli
2019-09-05  6:22   ` Juergen Gross

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