From patchwork Thu Jul 28 10:49:26 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhi Yong Wu X-Patchwork-Id: 1015272 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6SAqsQu026063 for ; Thu, 28 Jul 2011 10:52:54 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755320Ab1G1Kwv (ORCPT ); Thu, 28 Jul 2011 06:52:51 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:44454 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755219Ab1G1Kwv (ORCPT ); Thu, 28 Jul 2011 06:52:51 -0400 Received: from d03relay03.boulder.ibm.com (d03relay03.boulder.ibm.com [9.17.195.228]) by e32.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p6S9gsMp008168 for ; Thu, 28 Jul 2011 03:42:54 -0600 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p6SAqoe8121242 for ; Thu, 28 Jul 2011 04:52:50 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p6SAqnoK006969 for ; Thu, 28 Jul 2011 04:52:50 -0600 Received: from us.ibm.com ([9.123.136.155]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with SMTP id p6SAqjNg006820; Thu, 28 Jul 2011 04:52:45 -0600 Received: by us.ibm.com (sSMTP sendmail emulation); Thu, 28 Jul 2011 18:49:40 +0800 From: Zhi Yong Wu To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, stefanha@linux.vnet.ibm.com, mtosatti@redhat.com, aliguori@us.ibm.com, ryanh@us.ibm.com, zwu.kernel@gmail.com, kwolf@redhat.com, luowenj@cn.ibm.com, Zhi Yong Wu Subject: [PATCH v3 2/2] The implement of block queue, block timer, and I/O throttling algorithm Date: Thu, 28 Jul 2011 18:49:26 +0800 Message-Id: <1311850166-9404-3-git-send-email-wuzhy@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1311850166-9404-1-git-send-email-wuzhy@linux.vnet.ibm.com> References: <1311850166-9404-1-git-send-email-wuzhy@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Thu, 28 Jul 2011 10:52:54 +0000 (UTC) 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 --- block.c | 302 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- block.h | 1 - block_int.h | 29 ++++++ 3 files changed, 323 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index 24a25d5..c4c631b 100644 --- a/block.c +++ b/block.c @@ -29,6 +29,9 @@ #include "module.h" #include "qemu-objects.h" +#include "qemu-timer.h" +#include "block/blk-queue.h" + #ifdef CONFIG_BSD #include #include @@ -58,6 +61,13 @@ static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors); +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, uint64_t *wait); + static QTAILQ_HEAD(, BlockDriverState) bdrv_states = QTAILQ_HEAD_INITIALIZER(bdrv_states); @@ -90,6 +100,20 @@ int is_windows_drive(const char *filename) } #endif +static int bdrv_io_limits_enable(BlockIOLimit *io_limits) +{ + if ((io_limits->bps[0] == 0) + && (io_limits->bps[1] == 0) + && (io_limits->bps[2] == 0) + && (io_limits->iops[0] == 0) + && (io_limits->iops[1] == 0) + && (io_limits->iops[2] == 0)) { + return 0; + } + + return 1; +} + /* check if the path starts with ":" */ static int path_has_protocol(const char *path) { @@ -167,6 +191,28 @@ void path_combine(char *dest, int dest_size, } } +static void bdrv_block_timer(void *opaque) +{ + BlockDriverState *bs = opaque; + BlockQueue *queue = bs->block_queue; + + while (!QTAILQ_EMPTY(&queue->requests)) { + BlockIORequest *request; + int ret; + + request = QTAILQ_FIRST(&queue->requests); + QTAILQ_REMOVE(&queue->requests, request, entry); + + ret = qemu_block_queue_handler(request); + if (ret == 0) { + QTAILQ_INSERT_HEAD(&queue->requests, request, entry); + break; + } + + qemu_free(request); + } +} + void bdrv_register(BlockDriver *bdrv) { if (!bdrv->bdrv_aio_readv) { @@ -642,6 +688,19 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags, bs->change_cb(bs->change_opaque, CHANGE_MEDIA); } + /* throttling disk I/O limits */ + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->req_from_queue = false; + bs->block_queue = qemu_new_block_queue(); + bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs); + + bs->slice_start[0] = qemu_get_clock_ns(vm_clock); + bs->slice_start[1] = qemu_get_clock_ns(vm_clock); + + bs->slice_end[0] = qemu_get_clock_ns(vm_clock) + BLOCK_IO_SLICE_TIME; + bs->slice_end[1] = qemu_get_clock_ns(vm_clock) + BLOCK_IO_SLICE_TIME; + } + return 0; unlink_and_fail: @@ -680,6 +739,16 @@ 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); + } + + if (bs->block_timer) { + qemu_del_timer(bs->block_timer); + qemu_free_timer(bs->block_timer); + } } void bdrv_close_all(void) @@ -1312,6 +1381,14 @@ void bdrv_get_geometry_hint(BlockDriverState *bs, *psecs = bs->secs; } +/* throttling disk io limits */ +void bdrv_set_io_limits(BlockDriverState *bs, + BlockIOLimit *io_limits) +{ + memset(&bs->io_limits, 0, sizeof(BlockIOLimit)); + bs->io_limits = *io_limits; +} + /* Recognize floppy formats */ typedef struct FDFormat { FDriveType drive; @@ -2111,6 +2188,165 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn) return buf; } +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[is_write] - bs->slice_start[is_write]; + slice_time /= (BLOCK_IO_SLICE_TIME * 10.0); + 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; + } + + 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[is_write] - bs->slice_start[is_write]; + slice_time /= (BLOCK_IO_SLICE_TIME * 10.0); + 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, uint64_t *wait) { + int64_t real_time, real_slice; + uint64_t bps_wait = 0, iops_wait = 0, max_wait; + double elapsed_time; + int bps_ret, iops_ret; + + real_time = qemu_get_clock_ns(vm_clock); + real_slice = bs->slice_end[is_write] - bs->slice_start[is_write]; + if ((bs->slice_start[is_write] < real_time) + && (bs->slice_end[is_write] > real_time)) { + bs->slice_end[is_write] = real_time + BLOCK_IO_SLICE_TIME; + } else { + bs->slice_start[is_write] = real_time; + bs->slice_end[is_write] = real_time + 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 ((bs->req_from_queue == false) + && !QTAILQ_EMPTY(&bs->block_queue->requests)) { + 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 = 0; + } + + return true; + } + } + + elapsed_time = real_time - bs->slice_start[is_write]; + elapsed_time /= (BLOCK_IO_SLICE_TIME * 10.0); + + 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; + } + + real_time = qemu_get_clock_ns(vm_clock); + if (bs->slice_end[is_write] < real_time + max_wait) { + bs->slice_end[is_write] = real_time + max_wait; + } + + return true; + } + + if (wait) { + *wait = 0; + } + + return false; +} /**************************************************************/ /* async I/Os */ @@ -2121,13 +2357,28 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, { BlockDriver *drv = bs->drv; BlockDriverAIOCB *ret; + uint64_t wait_time = 0; 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)) { + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->req_from_queue = false; + } return NULL; + } + + /* throttling disk read I/O */ + if (bdrv_io_limits_enable(&bs->io_limits)) { + 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); + qemu_mod_timer(bs->block_timer, + wait_time + qemu_get_clock_ns(vm_clock)); + bs->req_from_queue = false; + return ret; + } + } ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors, cb, opaque); @@ -2136,6 +2387,16 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, /* Update stats even though technically transfer has not happened. */ bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE; bs->rd_ops ++; + + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->io_disps.bytes[BLOCK_IO_LIMIT_READ] += + (unsigned) nb_sectors * BDRV_SECTOR_SIZE; + bs->io_disps.ios[BLOCK_IO_LIMIT_READ]++; + } + } + + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->req_from_queue = false; } return ret; @@ -2184,15 +2445,18 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, BlockDriver *drv = bs->drv; BlockDriverAIOCB *ret; BlockCompleteData *blk_cb_data; + uint64_t wait_time = 0; 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)) { + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->req_from_queue = false; + } + return NULL; + } if (bs->dirty_bitmap) { blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb, @@ -2201,6 +2465,18 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, opaque = blk_cb_data; } + /* throttling disk write I/O */ + if (bdrv_io_limits_enable(&bs->io_limits)) { + 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); + qemu_mod_timer(bs->block_timer, + wait_time + qemu_get_clock_ns(vm_clock)); + bs->req_from_queue = false; + return ret; + } + } + ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, cb, opaque); @@ -2211,6 +2487,16 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { bs->wr_highest_sector = sector_num + nb_sectors - 1; } + + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->io_disps.bytes[BLOCK_IO_LIMIT_WRITE] += + (unsigned) nb_sectors * BDRV_SECTOR_SIZE; + bs->io_disps.ios[BLOCK_IO_LIMIT_WRITE]++; + } + } + + if (bdrv_io_limits_enable(&bs->io_limits)) { + bs->req_from_queue = false; } return ret; diff --git a/block.h b/block.h index 859d1d9..f0dac62 100644 --- a/block.h +++ b/block.h @@ -97,7 +97,6 @@ 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; diff --git a/block_int.h b/block_int.h index 1e265d2..1ca826b 100644 --- a/block_int.h +++ b/block_int.h @@ -27,10 +27,17 @@ #include "block.h" #include "qemu-option.h" #include "qemu-queue.h" +#include "block/blk-queue.h" #define BLOCK_FLAG_ENCRYPT 1 #define BLOCK_FLAG_COMPAT6 4 +#define BLOCK_IO_LIMIT_READ 0 +#define BLOCK_IO_LIMIT_WRITE 1 +#define BLOCK_IO_LIMIT_TOTAL 2 + +#define BLOCK_IO_SLICE_TIME 100000000 + #define BLOCK_OPT_SIZE "size" #define BLOCK_OPT_ENCRYPT "encryption" #define BLOCK_OPT_COMPAT6 "compat6" @@ -46,6 +53,16 @@ typedef struct AIOPool { BlockDriverAIOCB *free_aiocb; } AIOPool; +typedef struct BlockIOLimit { + uint64_t bps[3]; + uint64_t iops[3]; +} BlockIOLimit; + +typedef struct BlockIODisp { + uint64_t bytes[2]; + uint64_t ios[2]; +} BlockIODisp; + struct BlockDriver { const char *format_name; int instance_size; @@ -175,6 +192,15 @@ struct BlockDriverState { void *sync_aiocb; + /* the time for latest disk I/O */ + int64_t slice_start[2]; + int64_t slice_end[2]; + BlockIOLimit io_limits; + BlockIODisp io_disps; + BlockQueue *block_queue; + QEMUTimer *block_timer; + bool req_from_queue; + /* I/O stats (display with "info blockstats"). */ uint64_t rd_bytes; uint64_t wr_bytes; @@ -222,6 +248,9 @@ void qemu_aio_release(void *p); void *qemu_blockalign(BlockDriverState *bs, size_t size); +void bdrv_set_io_limits(BlockDriverState *bs, + BlockIOLimit *io_limits); + #ifdef _WIN32 int is_windows_drive(const char *filename); #endif