@@ -10,6 +10,7 @@ block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
block-obj-y += null.o mirror.o
+block-obj-y += throttle-groups.o
block-obj-y += nbd.o nbd-client.o sheepdog.o
block-obj-$(CONFIG_LIBISCSI) += iscsi.o
new file mode 100644
@@ -0,0 +1,244 @@
+/*
+ * QEMU block throttling group infrastructure
+ *
+ * Copyright (C) Nodalink, EURL. 2014
+ * Copyright (C) Igalia, S.L. 2015
+ *
+ * Authors:
+ * Benoît Canet <benoit.canet@nodalink.com>
+ * Alberto Garcia <berto@igalia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "block/throttle-groups.h"
+
+/* The ThrottleGroup structure (with its ThrottleState) is shared
+ * among different BlockDriverState and it's independent from
+ * AioContext, so in order to use it from different threads it needs
+ * its own locking.
+ *
+ * This locking is however handled internally in this file, so it's
+ * transparent to outside users.
+ *
+ * The whole ThrottleGroup structure is private and invisible to
+ * outside users, that only use it through its ThrottleState.
+ */
+typedef struct ThrottleGroup {
+ char *name; /* This is constant during the lifetime of the group */
+
+ QemuMutex lock;
+ ThrottleState ts;
+ QLIST_HEAD(, BlockDriverState) head;
+ BlockDriverState *tokens[2];
+
+ /* These two are protected by throttle_groups_lock */
+ unsigned refcount;
+ QTAILQ_ENTRY(ThrottleGroup) list;
+} ThrottleGroup;
+
+static QemuMutex throttle_groups_lock;
+static QTAILQ_HEAD(, ThrottleGroup) throttle_groups =
+ QTAILQ_HEAD_INITIALIZER(throttle_groups);
+
+/* Increments the reference count of a ThrottleGroup given its name.
+ *
+ * If no ThrottleGroup is found with the given name a new one is
+ * created.
+ *
+ * @name: the name of the ThrottleGroup
+ * @ret: the ThrottleGroup
+ */
+static ThrottleGroup *throttle_group_incref(const char *name)
+{
+ ThrottleGroup *tg = NULL;
+ ThrottleGroup *iter;
+
+ qemu_mutex_lock(&throttle_groups_lock);
+
+ /* Look for an existing group with that name */
+ QTAILQ_FOREACH(iter, &throttle_groups, list) {
+ if (!strcmp(name, iter->name)) {
+ tg = iter;
+ break;
+ }
+ }
+
+ /* Create a new one if not found */
+ if (!tg) {
+ tg = g_new0(ThrottleGroup, 1);
+ tg->name = g_strdup(name);
+ qemu_mutex_init(&tg->lock);
+ throttle_init(&tg->ts);
+ QLIST_INIT(&tg->head);
+
+ QTAILQ_INSERT_TAIL(&throttle_groups, tg, list);
+ }
+
+ tg->refcount++;
+
+ qemu_mutex_unlock(&throttle_groups_lock);
+
+ return tg;
+}
+
+/* Decrease the reference count of a ThrottleGroup.
+ *
+ * When the reference count reaches zero the ThrottleGroup is
+ * destroyed.
+ *
+ * @tg: The ThrottleGroup to unref
+ */
+static void throttle_group_unref(ThrottleGroup *tg)
+{
+ qemu_mutex_lock(&throttle_groups_lock);
+ if (--tg->refcount == 0) {
+ QTAILQ_REMOVE(&throttle_groups, tg, list);
+ qemu_mutex_destroy(&tg->lock);
+ g_free(tg->name);
+ g_free(tg);
+ }
+ qemu_mutex_unlock(&throttle_groups_lock);
+}
+
+/* Get the name from a ThrottleState's ThrottleGroup. The name (and
+ * the pointer) is guaranteed to remain constant during the lifetime
+ * of the group.
+ *
+ * @ts: the throttle state whose group we are inspecting
+ * @ret: the name of the group.
+ */
+const char *throttle_group_get_name(ThrottleState *ts)
+{
+ ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
+ return tg->name;
+}
+
+/* Return the next BlockDriverState in the round-robin sequence
+ *
+ * This takes care of simulating a circular list
+ *
+ * @bs: the current BlockDriverState
+ * @ret: the next BlockDriverState in the sequence
+ */
+static BlockDriverState *throttle_group_next_bs(BlockDriverState *bs)
+{
+ ThrottleState *ts = bs->throttle_state;
+ ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
+ BlockDriverState *next = QLIST_NEXT(bs, round_robin);
+
+ if (!next) {
+ return QLIST_FIRST(&tg->head);
+ }
+
+ return next;
+}
+
+/* Update the throttle configuration for a particular group. Similar
+ * to throttle_config(), but guarantees atomicity within the
+ * throttling group.
+ *
+ * @ts: the ThrottleState of the group to update.
+ * @tt: the throttle timers we use in this aio context
+ * @cfg: the configuration to set
+ */
+void throttle_group_config(ThrottleState *ts,
+ ThrottleTimers *tt,
+ ThrottleConfig *cfg)
+{
+ ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
+ qemu_mutex_lock(&tg->lock);
+ throttle_config(ts, tt, cfg);
+ qemu_mutex_unlock(&tg->lock);
+}
+
+/* Get the throttle configuration from a particular group. Similar to
+ * throttle_get_config(), but guarantees atomicity within the
+ * throttling group.
+ *
+ * @ts: the ThrottleState of the group.
+ * @cfg: the configuration will be written here
+ */
+void throttle_group_get_config(ThrottleState *ts, ThrottleConfig *cfg)
+{
+ ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
+ qemu_mutex_lock(&tg->lock);
+ throttle_get_config(ts, cfg);
+ qemu_mutex_unlock(&tg->lock);
+}
+
+/* Register a BlockDriverState in the throttling group, also updating
+ * its throttle_state pointer to point to it. If a throttling group
+ * with that name does not exist yet, it will be created.
+ *
+ * @bs: the BlockDriverState to insert
+ * @groupname: the name of the group
+ */
+void throttle_group_register_bs(BlockDriverState *bs, const char *groupname)
+{
+ int i;
+ ThrottleGroup *tg = throttle_group_incref(groupname);
+
+ bs->throttle_state = &tg->ts;
+
+ qemu_mutex_lock(&tg->lock);
+ /* If the ThrottleGroup is new set this BlockDriverState as the token */
+ for (i = 0; i < 2; i++) {
+ if (!tg->tokens[i]) {
+ tg->tokens[i] = bs;
+ }
+ }
+
+ QLIST_INSERT_HEAD(&tg->head, bs, round_robin);
+ qemu_mutex_unlock(&tg->lock);
+}
+
+/* Unregister a BlockDriverState from its group, removing it from the
+ * list and setting the throttle_state pointer to NULL.
+ *
+ * The group will be destroyed if it's empty after this operation.
+ *
+ * @bs: the BlockDriverState to remove
+ */
+void throttle_group_unregister_bs(BlockDriverState *bs)
+{
+ ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts);
+ int i;
+
+ qemu_mutex_lock(&tg->lock);
+ for (i = 0; i < 2; i++) {
+ if (tg->tokens[i] == bs) {
+ BlockDriverState *token = throttle_group_next_bs(bs);
+ /* Take care of the case where this is the last bs in the group */
+ if (token == bs) {
+ token = NULL;
+ }
+ tg->tokens[i] = token;
+ }
+ }
+
+ /* remove the current bs from the list */
+ QLIST_REMOVE(bs, round_robin);
+ qemu_mutex_unlock(&tg->lock);
+
+ throttle_group_unref(tg);
+ bs->throttle_state = NULL;
+}
+
+static void throttle_groups_init(void)
+{
+ qemu_mutex_init(&throttle_groups_lock);
+}
+
+block_init(throttle_groups_init);
@@ -363,6 +363,7 @@ struct BlockDriverState {
ThrottleTimers throttle_timers;
CoQueue throttled_reqs[2];
bool io_limits_enabled;
+ QLIST_ENTRY(BlockDriverState) round_robin;
/* I/O stats (display with "info blockstats"). */
BlockAcctStats stats;
new file mode 100644
@@ -0,0 +1,41 @@
+/*
+ * QEMU block throttling group infrastructure
+ *
+ * Copyright (C) Nodalink, EURL. 2014
+ * Copyright (C) Igalia, S.L. 2015
+ *
+ * Authors:
+ * Benoît Canet <benoit.canet@nodalink.com>
+ * Alberto Garcia <berto@igalia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef THROTTLE_GROUPS_H
+#define THROTTLE_GROUPS_H
+
+#include "qemu/throttle.h"
+#include "block/block_int.h"
+
+const char *throttle_group_get_name(ThrottleState *ts);
+
+void throttle_group_config(ThrottleState *ts,
+ ThrottleTimers *tt,
+ ThrottleConfig *cfg);
+void throttle_group_get_config(ThrottleState *ts, ThrottleConfig *cfg);
+
+void throttle_group_register_bs(BlockDriverState *bs, const char *groupname);
+void throttle_group_unregister_bs(BlockDriverState *bs);
+
+#endif
Signed-off-by: Alberto Garcia <berto@igalia.com> --- block/Makefile.objs | 1 + block/throttle-groups.c | 244 ++++++++++++++++++++++++++++++++++++++++ include/block/block_int.h | 1 + include/block/throttle-groups.h | 41 +++++++ 4 files changed, 287 insertions(+) create mode 100644 block/throttle-groups.c create mode 100644 include/block/throttle-groups.h