Note: 1.) When bps/iops limits are specified to a small value such as 511 bytes/s, this VM will hang up. We are considering how to handle this senario. 2.) When "dd" command is issued in guest, if its option bs is set to a large value such as "bs=1024K", the result speed will slightly bigger than the limits. For these problems, if you have nice thought, pls let us know.:) Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx> --- block.c | 259 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- block.h | 1 - 2 files changed, 248 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index cd75183..c08fde8 100644 --- a/block.c +++ b/block.c @@ -30,6 +30,9 @@ #include "qemu-objects.h" #include "qemu-coroutine.h" +#include "qemu-timer.h" +#include "block/blk-queue.h" + #ifdef CONFIG_BSD #include <sys/types.h> #include <sys/stat.h> @@ -72,6 +75,13 @@ static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, QEMUIOVector *iov); static int coroutine_fn bdrv_co_flush_em(BlockDriverState *bs); +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); @@ -745,6 +755,11 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags, bs->change_cb(bs->change_opaque, CHANGE_MEDIA); } + /* throttling disk I/O limits */ + if (bs->io_limits_enabled) { + bdrv_io_limits_enable(bs); + } + return 0; unlink_and_fail: @@ -783,6 +798,18 @@ void bdrv_close(BlockDriverState *bs) if (bs->change_cb) bs->change_cb(bs->change_opaque, CHANGE_MEDIA); } + + /* throttling disk I/O limits */ + if (bs->block_queue) { + qemu_del_block_queue(bs->block_queue); + bs->block_queue = NULL; + } + + if (bs->block_timer) { + qemu_del_timer(bs->block_timer); + qemu_free_timer(bs->block_timer); + bs->block_timer = NULL; + } } void bdrv_close_all(void) @@ -2341,16 +2368,48 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, BlockDriverCompletionFunc *cb, void *opaque) { BlockDriver *drv = bs->drv; - + BlockDriverAIOCB *ret; + int64_t wait_time = -1; +printf("sector_num=%ld, nb_sectors=%d\n", sector_num, nb_sectors); trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); - if (!drv) - return NULL; - if (bdrv_check_request(bs, sector_num, nb_sectors)) + if (!drv || bdrv_check_request(bs, sector_num, nb_sectors)) { return NULL; + } + + /* throttling disk read I/O */ + if (bs->io_limits_enabled) { + if (bdrv_exceed_io_limits(bs, nb_sectors, false, &wait_time)) { + ret = qemu_block_queue_enqueue(bs->block_queue, bs, bdrv_aio_readv, + sector_num, qiov, nb_sectors, cb, opaque); + printf("wait_time=%ld\n", wait_time); + if (wait_time != -1) { + printf("reset block timer\n"); + qemu_mod_timer(bs->block_timer, + wait_time + qemu_get_clock_ns(vm_clock)); + } + + if (ret) { + printf("ori ret is not null\n"); + } else { + printf("ori ret is null\n"); + } + + return ret; + } + } - return drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors, + ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors, cb, opaque); + if (ret) { + if (bs->io_limits_enabled) { + bs->io_disps.bytes[BLOCK_IO_LIMIT_READ] += + (unsigned) nb_sectors * BDRV_SECTOR_SIZE; + bs->io_disps.ios[BLOCK_IO_LIMIT_READ]++; + } + } + + return ret; } typedef struct BlockCompleteData { @@ -2396,15 +2455,14 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, BlockDriver *drv = bs->drv; BlockDriverAIOCB *ret; BlockCompleteData *blk_cb_data; + int64_t wait_time = -1; trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); - if (!drv) - return NULL; - if (bs->read_only) - return NULL; - if (bdrv_check_request(bs, sector_num, nb_sectors)) + if (!drv || bs->read_only + || bdrv_check_request(bs, sector_num, nb_sectors)) { return NULL; + } if (bs->dirty_bitmap) { blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb, @@ -2413,13 +2471,32 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, opaque = blk_cb_data; } + /* throttling disk write I/O */ + if (bs->io_limits_enabled) { + if (bdrv_exceed_io_limits(bs, nb_sectors, true, &wait_time)) { + ret = qemu_block_queue_enqueue(bs->block_queue, bs, bdrv_aio_writev, + sector_num, qiov, nb_sectors, cb, opaque); + if (wait_time != -1) { + qemu_mod_timer(bs->block_timer, + wait_time + qemu_get_clock_ns(vm_clock)); + } + + return ret; + } + } + ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, cb, opaque); - if (ret) { if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { bs->wr_highest_sector = sector_num + nb_sectors - 1; } + + if (bs->io_limits_enabled) { + bs->io_disps.bytes[BLOCK_IO_LIMIT_WRITE] += + (unsigned) nb_sectors * BDRV_SECTOR_SIZE; + bs->io_disps.ios[BLOCK_IO_LIMIT_WRITE]++; + } } return ret; @@ -2684,6 +2761,166 @@ void bdrv_aio_cancel(BlockDriverAIOCB *acb) acb->pool->cancel(acb); } +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->io_disps.bytes[is_write]; + if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { + bytes_disp += 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; + + if (wait) { + *wait = wait_time * BLOCK_IO_SLICE_TIME * 10; + } + + printf("1 wait=%ld\n", *wait); + 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->io_disps.ios[is_write]; + if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { + ios_disp += 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; + } + + 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 + BLOCK_IO_SLICE_TIME; + } else { + bs->slice_start = now; + bs->slice_end = now + BLOCK_IO_SLICE_TIME; + + bs->io_disps.bytes[is_write] = 0; + bs->io_disps.bytes[!is_write] = 0; + + bs->io_disps.ios[is_write] = 0; + bs->io_disps.ios[!is_write] = 0; + } + + /* If a limit was exceeded, immediately queue this request */ + if (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; + } + + printf("end wait=%ld\n", *wait); + + return true; + } + + if (wait) { + *wait = 0; + } + + return false; +} /**************************************************************/ /* async block device emulation */ diff --git a/block.h b/block.h index a3e69db..10d2828 100644 --- a/block.h +++ b/block.h @@ -107,7 +107,6 @@ int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, const char *backing_fmt); void bdrv_register(BlockDriver *bdrv); - typedef struct BdrvCheckResult { int corruptions; int leaks; -- 1.7.6 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html