Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
---
block.c | 360 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 348 insertions(+), 12 deletions(-)
diff --git a/block.c b/block.c
index 8f92950..2d85b64 100644
--- a/block.c
+++ b/block.c
@@ -63,9 +63,11 @@ static int coroutine_fn bdrv_co_writev_em(BlockDriverState
*bs,
int64_t sector_num, int nb_sectors,
QEMUIOVector *iov);
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ void *opaque, BlockAPIType co_type);
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ void *opaque, BlockAPIType co_type);
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
int64_t sector_num,
QEMUIOVector *qiov,
@@ -75,6 +77,13 @@ 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);
@@ -161,6 +170,26 @@ bool bdrv_io_limits_enabled(BlockDriverState *bs)
|| io_limits->iops[BLOCK_IO_LIMIT_TOTAL];
}
+static BlockQueueAIOCB *bdrv_io_limits_perform(BlockDriverState *bs,
+ BlockRequestHandler *handler, int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors)
+{
+ BlockQueueAIOCB *ret = NULL;
+ int64_t wait_time = -1;
+
+ if (bdrv_exceed_io_limits(bs, nb_sectors, false, &wait_time)) {
+ ret = qemu_block_queue_enqueue(bs->block_queue, bs, handler,
+ sector_num, qiov,
+ nb_sectors, NULL, NULL);
+ if (wait_time != -1) {
+ qemu_mod_timer(bs->block_timer,
+ wait_time + qemu_get_clock_ns(vm_clock));
+ }
+ }
+
+ return ret;
+}
+
/* check if the path starts with "<protocol>:" */
static int path_has_protocol(const char *path)
{
@@ -1112,10 +1141,12 @@ static void coroutine_fn bdrv_rw_co_entry(void *opaque)
if (!rwco->is_write) {
rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num,
- rwco->nb_sectors, rwco->qiov);
+ rwco->nb_sectors, rwco->qiov,
+ rwco, BDRV_API_SYNC);
} else {
rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num,
- rwco->nb_sectors, rwco->qiov);
+ rwco->nb_sectors, rwco->qiov,
+ rwco, BDRV_API_SYNC);
}
}
@@ -1331,6 +1362,17 @@ typedef struct BlockDriverAIOCBCoroutine {
void *blkq_acb;
} BlockDriverAIOCBCoroutine;
+static void bdrv_co_rw_bh(void *opaque)
+{
+ BlockDriverAIOCBCoroutine *acb = opaque;
+
+ acb->common.cb(acb->common.opaque, acb->req.error);
+
+ acb->blkq_acb = NULL;
+ qemu_bh_delete(acb->bh);
+ qemu_aio_release(acb);
+}
+
/* block I/O throttling */
typedef struct CoroutineCB {
BlockDriverState *bs;
@@ -1339,6 +1381,25 @@ typedef struct CoroutineCB {
QEMUIOVector *qiov;
} CoroutineCB;
+static bool bdrv_io_limits_skip_query(void *opaque,
+ BlockAPIType co_type) {
+ bool limit_skip;
+ RwCo *rwco;
+ BlockDriverAIOCBCoroutine *aioco;
+
+ if (co_type == BDRV_API_SYNC) {
+ rwco = opaque;
+ limit_skip = rwco->limit_skip;
+ } else if (co_type == BDRV_API_ASYNC) {
+ aioco = opaque;
+ limit_skip = aioco->limit_skip;
+ } else {
+ abort();
+ }
+
+ return limit_skip;
+}
+
static void bdrv_io_limits_skip_set(void *opaque,
BlockAPIType co_type,
bool cb_skip,
@@ -1379,13 +1440,52 @@ void bdrv_io_limits_issue_request(void *opaque,
}
}
+static int bdrv_io_limits_intercept(BlockDriverState *bs,
+ BlockRequestHandler *handler, int64_t sector_num,
+ QEMUIOVector *qiov, int nb_sectors, void *opaque, BlockAPIType co_type)
+{
+ BlockQueueAIOCB *blkq_acb = NULL;
+ BlockQueueRetType ret = BDRV_BLKQ_PASS;
+
+ blkq_acb = bdrv_io_limits_perform(bs, handler,
+ sector_num, qiov,
+ nb_sectors);
+ if (blkq_acb) {
+ blkq_acb->co_type = co_type;
+ blkq_acb->cocb = opaque;
+ if (co_type == BDRV_API_ASYNC) {
+ BlockDriverAIOCBCoroutine *aioco = opaque;
+ aioco->blkq_acb = blkq_acb;
+ aioco->cb_skip = true;
+ } else if (co_type == BDRV_API_CO) {
+ blkq_acb->co = qemu_coroutine_self();
+ }
+
+ ret = BDRV_BLKQ_ENQ_FIRST;
+ } else {
+ if (bs->block_queue->flushing) {
+ if (bs->block_queue->limit_exceeded) {
+ ret = BDRV_BLKQ_ENQ_AGAIN;
+ } else {
+ blkq_acb = opaque;
+ bdrv_io_limits_issue_request(blkq_acb, co_type);
+ ret = BDRV_BLKQ_DEQ_PASS;
+ }
+ }
+ }
+
+ return ret;
+}
+
/*
* Handle a read request in coroutine context
*/
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ void *opaque, BlockAPIType co_type)
{
BlockDriver *drv = bs->drv;
+ int ret;
if (!drv) {
return -ENOMEDIUM;
@@ -1394,6 +1494,28 @@ 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_skip_query(opaque, co_type)) {
+ ret = bdrv_io_limits_intercept(bs, bdrv_co_do_readv,
+ sector_num, qiov,
+ nb_sectors, opaque, co_type);
+ switch (ret) {
+ case BDRV_BLKQ_ENQ_FIRST:
+ if (co_type == BDRV_API_SYNC) {
+ ret = NOT_DONE;
+ } else if (co_type == BDRV_API_ASYNC) {
+ ret = 0;
+ } else if (co_type == BDRV_API_CO) {
+ qemu_coroutine_yield();
+ break;
+ }
+ case BDRV_BLKQ_ENQ_AGAIN:
+ case BDRV_BLKQ_DEQ_PASS:
+ return ret;
+ }
+ }
+
return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
}
@@ -1402,14 +1524,23 @@ int coroutine_fn bdrv_co_readv(BlockDriverState *bs,
int64_t sector_num,
{
trace_bdrv_co_readv(bs, sector_num, nb_sectors);
- return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov);
+ CoroutineCB cocb = {
+ .bs = bs,
+ .sector_num = sector_num,
+ .nb_sectors = nb_sectors,
+ .qiov = qiov,
+ };
+
+ return bdrv_co_do_readv(bs, sector_num, nb_sectors,
+ qiov, &cocb, BDRV_API_CO);
}
/*
* Handle a write request in coroutine context
*/
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
- int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
+ int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+ void *opaque, BlockAPIType co_type)
{
BlockDriver *drv = bs->drv;
int ret;
@@ -1424,6 +1555,28 @@ 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_skip_query(opaque, co_type)) {
+ ret = bdrv_io_limits_intercept(bs, bdrv_co_do_writev,
+ sector_num, qiov,
+ nb_sectors, opaque, co_type);
+ switch (ret) {
+ case BDRV_BLKQ_ENQ_FIRST:
+ if (co_type == BDRV_API_SYNC) {
+ ret = NOT_DONE;
+ } else if (co_type == BDRV_API_ASYNC) {
+ ret = 0;
+ } else if (co_type == BDRV_API_CO) {
+ qemu_coroutine_yield();
+ break;
+ }
+ case BDRV_BLKQ_ENQ_AGAIN:
+ case BDRV_BLKQ_DEQ_PASS:
+ return ret;
+ }
+ }
+
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
if (bs->dirty_bitmap) {
@@ -1442,7 +1595,15 @@ int coroutine_fn bdrv_co_writev(BlockDriverState *bs,
int64_t sector_num,
{
trace_bdrv_co_writev(bs, sector_num, nb_sectors);
- return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov);
+ CoroutineCB cocb = {
+ .bs = bs,
+ .sector_num = sector_num,
+ .nb_sectors = nb_sectors,
+ .qiov = qiov,
+ };
+
+ return bdrv_co_do_writev(bs, sector_num, nb_sectors,
+ qiov, &cocb, BDRV_API_CO);
}
/**
@@ -2709,6 +2870,170 @@ 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];
+ }
+
+ /* If a limit was exceeded, immediately queue this request */
+ if (!bs->block_queue->flushing
+ && qemu_block_queue_has_pending(bs->block_queue)) {
+ if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]
+ || bs->io_limits.bps[is_write] || bs->io_limits.iops[is_write]
+ || bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) {
+ if (wait) {
+ *wait = -1;
+ }
+
+ return true;
+ }
+ }
+
+ 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 (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 */
@@ -2798,6 +3123,15 @@ static BlockDriverAIOCB
*bdrv_aio_writev_em(BlockDriverState *bs,
static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb)
{
qemu_aio_flush();
+
+ BlockDriverAIOCBCoroutine *co_acb =
+ container_of(blockacb, BlockDriverAIOCBCoroutine, common);
+ if (co_acb->blkq_acb) {
+ BlockDriverAIOCB *acb_com = (BlockDriverAIOCB *)co_acb->blkq_acb;
+ assert(acb_com->bs);
+ acb_com->pool->cancel(acb_com);
+ co_acb->blkq_acb = NULL;
+ }
}
static AIOPool bdrv_em_co_aio_pool = {
@@ -2822,14 +3156,16 @@ static void coroutine_fn bdrv_co_do_rw(void *opaque)
if (!acb->is_write) {
acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov);
+ acb->req.nb_sectors, acb->req.qiov, acb, BDRV_API_ASYNC);
} else {
acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
- acb->req.nb_sectors, acb->req.qiov);
+ acb->req.nb_sectors, acb->req.qiov, acb, BDRV_API_ASYNC);
}
- acb->bh = qemu_bh_new(bdrv_co_em_bh, acb);
- qemu_bh_schedule(acb->bh);
+ if (!acb->cb_skip) {
+ acb->bh = qemu_bh_new(bdrv_co_rw_bh, acb);
+ qemu_bh_schedule(acb->bh);
+ }
}
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
--
1.7.6
