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authorRajithaY <rajithax.yerrumsetty@intel.com>2017-04-25 03:31:15 -0700
committerRajitha Yerrumchetty <rajithax.yerrumsetty@intel.com>2017-05-22 06:48:08 +0000
commitbb756eebdac6fd24e8919e2c43f7d2c8c4091f59 (patch)
treeca11e03542edf2d8f631efeca5e1626d211107e3 /qemu/block/throttle-groups.c
parenta14b48d18a9ed03ec191cf16b162206998a895ce (diff)
Adding qemu as a submodule of KVMFORNFV
This Patch includes the changes to add qemu as a submodule to kvmfornfv repo and make use of the updated latest qemu for the execution of all testcase Change-Id: I1280af507a857675c7f81d30c95255635667bdd7 Signed-off-by:RajithaY<rajithax.yerrumsetty@intel.com>
Diffstat (limited to 'qemu/block/throttle-groups.c')
-rw-r--r--qemu/block/throttle-groups.c483
1 files changed, 0 insertions, 483 deletions
diff --git a/qemu/block/throttle-groups.c b/qemu/block/throttle-groups.c
deleted file mode 100644
index 4920e0949..000000000
--- a/qemu/block/throttle-groups.c
+++ /dev/null
@@ -1,483 +0,0 @@
-/*
- * QEMU block throttling group infrastructure
- *
- * Copyright (C) Nodalink, EURL. 2014
- * Copyright (C) Igalia, S.L. 2015
- *
- * Authors:
- * BenoƮt 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 "qemu/osdep.h"
-#include "block/throttle-groups.h"
-#include "qemu/queue.h"
-#include "qemu/thread.h"
-#include "sysemu/qtest.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.
- *
- * In addition to the ThrottleGroup structure, BlockDriverState has
- * fields that need to be accessed by other members of the group and
- * therefore also need to be protected by this lock. Once a BDS is
- * registered in a group those fields can be accessed by other threads
- * any time.
- *
- * Again, all this is handled internally and is mostly transparent to
- * the outside. The 'throttle_timers' field however has an additional
- * constraint because it may be temporarily invalid (see for example
- * bdrv_set_aio_context()). Therefore in this file a thread will
- * access some other BDS's timers only after verifying that that BDS
- * has throttled requests in the queue.
- */
-typedef struct ThrottleGroup {
- char *name; /* This is constant during the lifetime of the group */
-
- QemuMutex lock; /* This lock protects the following four fields */
- ThrottleState ts;
- QLIST_HEAD(, BlockDriverState) head;
- BlockDriverState *tokens[2];
- bool any_timer_armed[2];
-
- /* These two are protected by the global 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 ThrottleState member of the ThrottleGroup
- */
-ThrottleState *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->ts;
-}
-
-/* Decrease the reference count of a ThrottleGroup.
- *
- * When the reference count reaches zero the ThrottleGroup is
- * destroyed.
- *
- * @ts: The ThrottleGroup to unref, given by its ThrottleState member
- */
-void throttle_group_unref(ThrottleState *ts)
-{
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
-
- 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 BlockDriverState's ThrottleGroup. The name (and
- * the pointer) is guaranteed to remain constant during the lifetime
- * of the group.
- *
- * @bs: a BlockDriverState that is member of a throttling group
- * @ret: the name of the group.
- */
-const char *throttle_group_get_name(BlockDriverState *bs)
-{
- ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts);
- return tg->name;
-}
-
-/* Return the next BlockDriverState in the round-robin sequence,
- * simulating a circular list.
- *
- * This assumes that tg->lock is held.
- *
- * @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;
-}
-
-/* Return the next BlockDriverState in the round-robin sequence with
- * pending I/O requests.
- *
- * This assumes that tg->lock is held.
- *
- * @bs: the current BlockDriverState
- * @is_write: the type of operation (read/write)
- * @ret: the next BlockDriverState with pending requests, or bs
- * if there is none.
- */
-static BlockDriverState *next_throttle_token(BlockDriverState *bs,
- bool is_write)
-{
- ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts);
- BlockDriverState *token, *start;
-
- start = token = tg->tokens[is_write];
-
- /* get next bs round in round robin style */
- token = throttle_group_next_bs(token);
- while (token != start && !token->pending_reqs[is_write]) {
- token = throttle_group_next_bs(token);
- }
-
- /* If no IO are queued for scheduling on the next round robin token
- * then decide the token is the current bs because chances are
- * the current bs get the current request queued.
- */
- if (token == start && !token->pending_reqs[is_write]) {
- token = bs;
- }
-
- return token;
-}
-
-/* Check if the next I/O request for a BlockDriverState needs to be
- * throttled or not. If there's no timer set in this group, set one
- * and update the token accordingly.
- *
- * This assumes that tg->lock is held.
- *
- * @bs: the current BlockDriverState
- * @is_write: the type of operation (read/write)
- * @ret: whether the I/O request needs to be throttled or not
- */
-static bool throttle_group_schedule_timer(BlockDriverState *bs,
- bool is_write)
-{
- ThrottleState *ts = bs->throttle_state;
- ThrottleTimers *tt = &bs->throttle_timers;
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- bool must_wait;
-
- /* Check if any of the timers in this group is already armed */
- if (tg->any_timer_armed[is_write]) {
- return true;
- }
-
- must_wait = throttle_schedule_timer(ts, tt, is_write);
-
- /* If a timer just got armed, set bs as the current token */
- if (must_wait) {
- tg->tokens[is_write] = bs;
- tg->any_timer_armed[is_write] = true;
- }
-
- return must_wait;
-}
-
-/* Look for the next pending I/O request and schedule it.
- *
- * This assumes that tg->lock is held.
- *
- * @bs: the current BlockDriverState
- * @is_write: the type of operation (read/write)
- */
-static void schedule_next_request(BlockDriverState *bs, bool is_write)
-{
- ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts);
- bool must_wait;
- BlockDriverState *token;
-
- /* Check if there's any pending request to schedule next */
- token = next_throttle_token(bs, is_write);
- if (!token->pending_reqs[is_write]) {
- return;
- }
-
- /* Set a timer for the request if it needs to be throttled */
- must_wait = throttle_group_schedule_timer(token, is_write);
-
- /* If it doesn't have to wait, queue it for immediate execution */
- if (!must_wait) {
- /* Give preference to requests from the current bs */
- if (qemu_in_coroutine() &&
- qemu_co_queue_next(&bs->throttled_reqs[is_write])) {
- token = bs;
- } else {
- ThrottleTimers *tt = &token->throttle_timers;
- int64_t now = qemu_clock_get_ns(tt->clock_type);
- timer_mod(tt->timers[is_write], now + 1);
- tg->any_timer_armed[is_write] = true;
- }
- tg->tokens[is_write] = token;
- }
-}
-
-/* Check if an I/O request needs to be throttled, wait and set a timer
- * if necessary, and schedule the next request using a round robin
- * algorithm.
- *
- * @bs: the current BlockDriverState
- * @bytes: the number of bytes for this I/O
- * @is_write: the type of operation (read/write)
- */
-void coroutine_fn throttle_group_co_io_limits_intercept(BlockDriverState *bs,
- unsigned int bytes,
- bool is_write)
-{
- bool must_wait;
- BlockDriverState *token;
-
- ThrottleGroup *tg = container_of(bs->throttle_state, ThrottleGroup, ts);
- qemu_mutex_lock(&tg->lock);
-
- /* First we check if this I/O has to be throttled. */
- token = next_throttle_token(bs, is_write);
- must_wait = throttle_group_schedule_timer(token, is_write);
-
- /* Wait if there's a timer set or queued requests of this type */
- if (must_wait || bs->pending_reqs[is_write]) {
- bs->pending_reqs[is_write]++;
- qemu_mutex_unlock(&tg->lock);
- qemu_co_queue_wait(&bs->throttled_reqs[is_write]);
- qemu_mutex_lock(&tg->lock);
- bs->pending_reqs[is_write]--;
- }
-
- /* The I/O will be executed, so do the accounting */
- throttle_account(bs->throttle_state, is_write, bytes);
-
- /* Schedule the next request */
- schedule_next_request(bs, is_write);
-
- qemu_mutex_unlock(&tg->lock);
-}
-
-/* Update the throttle configuration for a particular group. Similar
- * to throttle_config(), but guarantees atomicity within the
- * throttling group.
- *
- * @bs: a BlockDriverState that is member of the group
- * @cfg: the configuration to set
- */
-void throttle_group_config(BlockDriverState *bs, ThrottleConfig *cfg)
-{
- ThrottleTimers *tt = &bs->throttle_timers;
- ThrottleState *ts = bs->throttle_state;
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- qemu_mutex_lock(&tg->lock);
- /* throttle_config() cancels the timers */
- if (timer_pending(tt->timers[0])) {
- tg->any_timer_armed[0] = false;
- }
- if (timer_pending(tt->timers[1])) {
- tg->any_timer_armed[1] = false;
- }
- 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.
- *
- * @bs: a BlockDriverState that is member of the group
- * @cfg: the configuration will be written here
- */
-void throttle_group_get_config(BlockDriverState *bs, ThrottleConfig *cfg)
-{
- ThrottleState *ts = bs->throttle_state;
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- qemu_mutex_lock(&tg->lock);
- throttle_get_config(ts, cfg);
- qemu_mutex_unlock(&tg->lock);
-}
-
-/* ThrottleTimers callback. This wakes up a request that was waiting
- * because it had been throttled.
- *
- * @bs: the BlockDriverState whose request had been throttled
- * @is_write: the type of operation (read/write)
- */
-static void timer_cb(BlockDriverState *bs, bool is_write)
-{
- ThrottleState *ts = bs->throttle_state;
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- bool empty_queue;
-
- /* The timer has just been fired, so we can update the flag */
- qemu_mutex_lock(&tg->lock);
- tg->any_timer_armed[is_write] = false;
- qemu_mutex_unlock(&tg->lock);
-
- /* Run the request that was waiting for this timer */
- empty_queue = !qemu_co_enter_next(&bs->throttled_reqs[is_write]);
-
- /* If the request queue was empty then we have to take care of
- * scheduling the next one */
- if (empty_queue) {
- qemu_mutex_lock(&tg->lock);
- schedule_next_request(bs, is_write);
- qemu_mutex_unlock(&tg->lock);
- }
-}
-
-static void read_timer_cb(void *opaque)
-{
- timer_cb(opaque, false);
-}
-
-static void write_timer_cb(void *opaque)
-{
- timer_cb(opaque, true);
-}
-
-/* Register a BlockDriverState in the throttling group, also
- * initializing its timers and 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;
- ThrottleState *ts = throttle_group_incref(groupname);
- ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);
- int clock_type = QEMU_CLOCK_REALTIME;
-
- if (qtest_enabled()) {
- /* For testing block IO throttling only */
- clock_type = QEMU_CLOCK_VIRTUAL;
- }
-
- bs->throttle_state = 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);
-
- throttle_timers_init(&bs->throttle_timers,
- bdrv_get_aio_context(bs),
- clock_type,
- read_timer_cb,
- write_timer_cb,
- bs);
-
- qemu_mutex_unlock(&tg->lock);
-}
-
-/* Unregister a BlockDriverState from its group, removing it from the
- * list, destroying the timers and setting the throttle_state pointer
- * to NULL.
- *
- * The BlockDriverState must not have pending throttled requests, so
- * the caller has to drain them first.
- *
- * 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;
-
- assert(bs->pending_reqs[0] == 0 && bs->pending_reqs[1] == 0);
- assert(qemu_co_queue_empty(&bs->throttled_reqs[0]));
- assert(qemu_co_queue_empty(&bs->throttled_reqs[1]));
-
- 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);
- throttle_timers_destroy(&bs->throttle_timers);
- qemu_mutex_unlock(&tg->lock);
-
- throttle_group_unref(&tg->ts);
- bs->throttle_state = NULL;
-}
-
-static void throttle_groups_init(void)
-{
- qemu_mutex_init(&throttle_groups_lock);
-}
-
-block_init(throttle_groups_init);