@@ -74,6 +74,13 @@ static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
bool is_write);
static void coroutine_fn bdrv_co_do_rw(void *opaque);
+static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
+ bool is_write, double elapsed_time, uint64_t *wait);
+static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
+ double elapsed_time, uint64_t *wait);
+static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
+ bool is_write, int64_t *wait);
+
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -107,6 +114,28 @@ int is_windows_drive(const char *filename)
#endif
/* throttling disk I/O limits */
+void bdrv_io_limits_disable(BlockDriverState *bs)
+{
+ bs->io_limits_enabled = false;
+
+ if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+ while (qemu_co_queue_next(&bs->throttled_reqs));
+ }
+
+ qemu_co_queue_init(&bs->throttled_reqs);
+
+ if (bs->block_timer) {
+ qemu_del_timer(bs->block_timer);
+ qemu_free_timer(bs->block_timer);
+ bs->block_timer = NULL;
+ }
+
+ bs->slice_start = 0;
+ bs->slice_end = 0;
+ bs->slice_time = 0;
+ memset(&bs->io_disps, 0, sizeof(bs->io_disps));
+}
+
static void bdrv_block_timer(void *opaque)
{
BlockDriverState *bs = opaque;
@@ -137,6 +166,35 @@ bool bdrv_io_limits_enabled(BlockDriverState *bs)
|| io_limits->iops[BLOCK_IO_LIMIT_TOTAL];
}
+static void bdrv_io_limits_intercept(BlockDriverState *bs,
+ bool is_write, int nb_sectors)
+{
+ int64_t wait_time = -1;
+
+ if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+ qemu_co_queue_wait(&bs->throttled_reqs);
+ goto resume;
+ } else if (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) {
+ if (wait_time != -1) {
+ qemu_mod_timer(bs->block_timer,
+ wait_time + qemu_get_clock_ns(vm_clock));
+ }
+
+ qemu_co_queue_wait(&bs->throttled_reqs);
+
+resume:
+ while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) {
+ if (wait_time != -1) {
+ qemu_mod_timer(bs->block_timer,
+ wait_time + qemu_get_clock_ns(vm_clock));
+ }
+ qemu_co_queue_wait_insert_head(&bs->throttled_reqs);
+ }
+
+ qemu_co_queue_next(&bs->throttled_reqs);
+ }
+}
+
/* check if the path starts with "<protocol>:" */
static int path_has_protocol(const char *path)
{
@@ -719,6 +777,11 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
bdrv_dev_change_media_cb(bs, true);
}
+ /* throttling disk I/O limits */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_enable(bs);
+ }
+
return 0;
unlink_and_fail:
@@ -754,6 +817,9 @@ void bdrv_close(BlockDriverState *bs)
bdrv_dev_change_media_cb(bs, false);
}
+
+ /*throttling disk I/O limits*/
+ bdrv_io_limits_disable(bs);
}
void bdrv_close_all(void)
@@ -1292,6 +1358,11 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
return -EIO;
}
+ /* throttling disk read I/O */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_intercept(bs, false, nb_sectors);
+ }
+
return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
}
@@ -1322,6 +1393,11 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
return -EIO;
}
+ /* throttling disk write I/O */
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_intercept(bs, true, nb_sectors);
+ }
+
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
if (bs->dirty_bitmap) {
@@ -2513,6 +2589,160 @@ void bdrv_aio_cancel(BlockDriverAIOCB *acb)
acb->pool->cancel(acb);
}
+/* block I/O throttling */
+static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
+ bool is_write, double elapsed_time, uint64_t *wait) {
+ uint64_t bps_limit = 0;
+ double bytes_limit, bytes_disp, bytes_res;
+ double slice_time, wait_time;
+
+ if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
+ bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL];
+ } else if (bs->io_limits.bps[is_write]) {
+ bps_limit = bs->io_limits.bps[is_write];
+ } else {
+ if (wait) {
+ *wait = 0;
+ }
+
+ return false;
+ }
+
+ slice_time = bs->slice_end - bs->slice_start;
+ slice_time /= (NANOSECONDS_PER_SECOND);
+ bytes_limit = bps_limit * slice_time;
+ bytes_disp = bs->nr_bytes[is_write] - bs->io_disps.bytes[is_write];
+ if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) {
+ bytes_disp += bs->nr_bytes[!is_write] - bs->io_disps.bytes[!is_write];
+ }
+
+ bytes_res = (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
+
+ if (bytes_disp + bytes_res <= bytes_limit) {
+ if (wait) {
+ *wait = 0;
+ }
+
+ return false;
+ }
+
+ /* Calc approx time to dispatch */
+ wait_time = (bytes_disp + bytes_res) / bps_limit - elapsed_time;
+
+ bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
+ bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
+ if (wait) {
+ *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+ }
+
+ return true;
+}
+
+static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
+ double elapsed_time, uint64_t *wait) {
+ uint64_t iops_limit = 0;
+ double ios_limit, ios_disp;
+ double slice_time, wait_time;
+
+ if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
+ iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL];
+ } else if (bs->io_limits.iops[is_write]) {
+ iops_limit = bs->io_limits.iops[is_write];
+ } else {
+ if (wait) {
+ *wait = 0;
+ }
+
+ return false;
+ }
+
+ slice_time = bs->slice_end - bs->slice_start;
+ slice_time /= (NANOSECONDS_PER_SECOND);
+ ios_limit = iops_limit * slice_time;
+ ios_disp = bs->nr_ops[is_write] - bs->io_disps.ios[is_write];
+ if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
+ ios_disp += bs->nr_ops[!is_write] - bs->io_disps.ios[!is_write];
+ }
+
+ if (ios_disp + 1 <= ios_limit) {
+ if (wait) {
+ *wait = 0;
+ }
+
+ return false;
+ }
+
+ /* Calc approx time to dispatch */
+ wait_time = (ios_disp + 1) / iops_limit;
+ if (wait_time > elapsed_time) {
+ wait_time = wait_time - elapsed_time;
+ } else {
+ wait_time = 0;
+ }
+
+ bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10;
+ bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME;
+ if (wait) {
+ *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+ }
+
+ return true;
+}
+
+static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
+ bool is_write, int64_t *wait) {
+ int64_t now, max_wait;
+ uint64_t bps_wait = 0, iops_wait = 0;
+ double elapsed_time;
+ int bps_ret, iops_ret;
+
+ now = qemu_get_clock_ns(vm_clock);
+ if ((bs->slice_start < now)
+ && (bs->slice_end > now)) {
+ bs->slice_end = now + bs->slice_time;
+ } else {
+ bs->slice_time = 5 * BLOCK_IO_SLICE_TIME;
+ bs->slice_start = now;
+ bs->slice_end = now + bs->slice_time;
+
+ bs->io_disps.bytes[is_write] = bs->nr_bytes[is_write];
+ bs->io_disps.bytes[!is_write] = bs->nr_bytes[!is_write];
+
+ bs->io_disps.ios[is_write] = bs->nr_ops[is_write];
+ bs->io_disps.ios[!is_write] = bs->nr_ops[!is_write];
+ }
+
+ elapsed_time = now - bs->slice_start;
+ elapsed_time /= (NANOSECONDS_PER_SECOND);
+
+ bps_ret = bdrv_exceed_bps_limits(bs, nb_sectors,
+ is_write, elapsed_time, &bps_wait);
+ iops_ret = bdrv_exceed_iops_limits(bs, is_write,
+ elapsed_time, &iops_wait);
+ if (bps_ret || iops_ret) {
+ max_wait = bps_wait > iops_wait ? bps_wait : iops_wait;
+ if (!qemu_co_queue_empty(&bs->throttled_reqs)) {
+ max_wait = -1;
+ }
+
+ if (wait) {
+ *wait = max_wait;
+ }
+
+ now = qemu_get_clock_ns(vm_clock);
+ if (bs->slice_end < now + max_wait) {
+ bs->slice_end = now + max_wait;
+ }
+
+ return true;
+ }
+
+ if (wait) {
+ *wait = 0;
+ }
+
+ return false;
+}
/**************************************************************/
/* async block device emulation */
@@ -91,6 +91,7 @@ void bdrv_info_stats(Monitor *mon, QObject **ret_data);
/* disk I/O throttling */
void bdrv_io_limits_enable(BlockDriverState *bs);
+void bdrv_io_limits_disable(BlockDriverState *bs);
bool bdrv_io_limits_enabled(BlockDriverState *bs);
void bdrv_init(void);
@@ -39,6 +39,7 @@
#define BLOCK_IO_LIMIT_TOTAL 2
#define BLOCK_IO_SLICE_TIME 100000000
+#define NANOSECONDS_PER_SECOND 1000000000.0
#define BLOCK_OPT_SIZE "size"
#define BLOCK_OPT_ENCRYPT "encryption"
@@ -61,6 +61,14 @@ void coroutine_fn qemu_co_queue_wait(CoQueue *queue)
assert(qemu_in_coroutine());
}
+void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue)
+{
+ Coroutine *self = qemu_coroutine_self();
+ QTAILQ_INSERT_HEAD(&queue->entries, self, co_queue_next);
+ qemu_coroutine_yield();
+ assert(qemu_in_coroutine());
+}
+
bool qemu_co_queue_next(CoQueue *queue)
{
Coroutine *next;
@@ -118,6 +118,12 @@ void qemu_co_queue_init(CoQueue *queue);
void coroutine_fn qemu_co_queue_wait(CoQueue *queue);
/**
+ * Adds the current coroutine to the head of the CoQueue and transfers control to the
+ * caller of the coroutine.
+ */
+void coroutine_fn qemu_co_queue_wait_insert_head(CoQueue *queue);
+
+/**
* Restarts the next coroutine in the CoQueue and removes it from the queue.
*
* Returns true if a coroutine was restarted, false if the queue is empty.
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> --- block.c | 230 +++++++++++++++++++++++++++++++++++++++++++++++++ block.h | 1 + block_int.h | 1 + qemu-coroutine-lock.c | 8 ++ qemu-coroutine.h | 6 ++ 5 files changed, 246 insertions(+), 0 deletions(-)