drbd: Move cpu_mask from connection to resource

Also fix drbd_calc_cpu_mask() to spread resources equally over all online cpus
independent of device minor numbers.

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index af68d64..95d9c5c 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -584,6 +584,8 @@ struct drbd_resource {
        unsigned susp:1;                /* IO suspended by user */
        unsigned susp_nod:1;            /* IO suspended because no data */
        unsigned susp_fen:1;            /* IO suspended because fence peer handler runs */
+
+       cpumask_var_t cpu_mask;
 };
 
 struct drbd_connection {
@@ -632,7 +634,6 @@ struct drbd_connection {
        struct drbd_thread receiver;
        struct drbd_thread worker;
        struct drbd_thread asender;
-       cpumask_var_t cpu_mask;
 
        /* sender side */
        struct drbd_work_queue sender_work;
@@ -880,10 +881,8 @@ extern void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait);
 extern char *drbd_task_to_thread_name(struct drbd_connection *connection, struct task_struct *task);
 #ifdef CONFIG_SMP
 extern void drbd_thread_current_set_cpu(struct drbd_thread *thi);
-extern void drbd_calc_cpu_mask(struct drbd_connection *connection);
 #else
 #define drbd_thread_current_set_cpu(A) ({})
-#define drbd_calc_cpu_mask(A) ({})
 #endif
 extern void tl_release(struct drbd_connection *, unsigned int barrier_nr,
                       unsigned int set_size);

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 59a58e8..b0b2eb1 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -511,28 +511,38 @@ int conn_lowest_minor(struct drbd_connection *connection)
 #ifdef CONFIG_SMP
 /**
  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
- * @device:    DRBD device.
  *
- * Forces all threads of a device onto the same CPU. This is beneficial for
+ * Forces all threads of a resource onto the same CPU. This is beneficial for
  * DRBD's performance. May be overwritten by user's configuration.
  */
-void drbd_calc_cpu_mask(struct drbd_connection *connection)
+static void drbd_calc_cpu_mask(cpumask_var_t *cpu_mask)
 {
-       int ord, cpu;
+       unsigned int *resources_per_cpu, min_index = ~0;
 
-       /* user override. */
-       if (cpumask_weight(connection->cpu_mask))
-               return;
+       resources_per_cpu = kzalloc(nr_cpu_ids * sizeof(*resources_per_cpu), GFP_KERNEL);
+       if (resources_per_cpu) {
+               struct drbd_resource *resource;
+               unsigned int cpu, min = ~0;
 
-       ord = conn_lowest_minor(connection) % cpumask_weight(cpu_online_mask);
-       for_each_online_cpu(cpu) {
-               if (ord-- == 0) {
-                       cpumask_set_cpu(cpu, connection->cpu_mask);
-                       return;
+               rcu_read_lock();
+               for_each_resource_rcu(resource, &drbd_resources) {
+                       for_each_cpu(cpu, resource->cpu_mask)
+                               resources_per_cpu[cpu]++;
                }
+               rcu_read_unlock();
+               for_each_online_cpu(cpu) {
+                       if (resources_per_cpu[cpu] < min) {
+                               min = resources_per_cpu[cpu];
+                               min_index = cpu;
+                       }
+               }
+               kfree(resources_per_cpu);
+       }
+       if (min_index == ~0) {
+               cpumask_setall(*cpu_mask);
+               return;
        }
-       /* should not be reached */
-       cpumask_setall(connection->cpu_mask);
+       cpumask_set_cpu(min_index, *cpu_mask);
 }
 
 /**
@@ -550,8 +560,10 @@ void drbd_thread_current_set_cpu(struct drbd_thread *thi)
        if (!thi->reset_cpu_mask)
                return;
        thi->reset_cpu_mask = 0;
-       set_cpus_allowed_ptr(p, thi->connection->cpu_mask);
+       set_cpus_allowed_ptr(p, thi->connection->resource->cpu_mask);
 }
+#else
+#define drbd_calc_cpu_mask(A) ({})
 #endif
 
 /**
@@ -2287,6 +2299,7 @@ void drbd_destroy_resource(struct kref *kref)
                container_of(kref, struct drbd_resource, kref);
 
        idr_destroy(&resource->devices);
+       free_cpumask_var(resource->cpu_mask);
        kfree(resource->name);
        kfree(resource);
 }
@@ -2512,10 +2525,11 @@ int set_resource_options(struct drbd_resource *resource, struct res_opts *res_op
                }
        }
        resource->res_opts = *res_opts;
-       for_each_connection_rcu(connection, resource) {
-               if (!cpumask_equal(connection->cpu_mask, new_cpu_mask)) {
-                       cpumask_copy(connection->cpu_mask, new_cpu_mask);
-                       drbd_calc_cpu_mask(connection);
+       if (cpumask_empty(new_cpu_mask))
+               drbd_calc_cpu_mask(&new_cpu_mask);
+       if (!cpumask_equal(resource->cpu_mask, new_cpu_mask)) {
+               cpumask_copy(resource->cpu_mask, new_cpu_mask);
+               for_each_connection_rcu(connection, resource) {
                        connection->receiver.reset_cpu_mask = 1;
                        connection->asender.reset_cpu_mask = 1;
                        connection->worker.reset_cpu_mask = 1;
@@ -2535,12 +2549,12 @@ struct drbd_resource *drbd_create_resource(const char *name)
 
        resource = kzalloc(sizeof(struct drbd_resource), GFP_KERNEL);
        if (!resource)
-               return NULL;
+               goto fail;
        resource->name = kstrdup(name, GFP_KERNEL);
-       if (!resource->name) {
-               kfree(resource);
-               return NULL;
-       }
+       if (!resource->name)
+               goto fail_free_resource;
+       if (!zalloc_cpumask_var(&resource->cpu_mask, GFP_KERNEL))
+               goto fail_free_name;
        kref_init(&resource->kref);
        idr_init(&resource->devices);
        INIT_LIST_HEAD(&resource->connections);
@@ -2548,6 +2562,13 @@ struct drbd_resource *drbd_create_resource(const char *name)
        mutex_init(&resource->conf_update);
        spin_lock_init(&resource->req_lock);
        return resource;
+
+fail_free_name:
+       kfree(resource->name);
+fail_free_resource:
+       kfree(resource);
+fail:
+       return NULL;
 }
 
 /* caller must be under genl_lock() */
@@ -2565,9 +2586,6 @@ struct drbd_connection *conn_create(const char *name, struct res_opts *res_opts)
        if (drbd_alloc_socket(&connection->meta))
                goto fail;
 
-       if (!zalloc_cpumask_var(&connection->cpu_mask, GFP_KERNEL))
-               goto fail;
-
        connection->current_epoch = kzalloc(sizeof(struct drbd_epoch), GFP_KERNEL);
        if (!connection->current_epoch)
                goto fail;
@@ -2616,7 +2634,6 @@ fail_resource:
        drbd_free_resource(resource);
 fail:
        kfree(connection->current_epoch);
-       free_cpumask_var(connection->cpu_mask);
        drbd_free_socket(&connection->meta);
        drbd_free_socket(&connection->data);
        kfree(connection);
@@ -2634,7 +2651,6 @@ void drbd_destroy_connection(struct kref *kref)
 
        idr_destroy(&connection->peer_devices);
 
-       free_cpumask_var(connection->cpu_mask);
        drbd_free_socket(&connection->meta);
        drbd_free_socket(&connection->data);
        kfree(connection->int_dig_in);