qemu-img: add support for rate limit in qemu-img convert

Commit Message

Zhengui li Oct. 18, 2020, 6:34 a.m. UTC

From: Zhengui <[e-mail]>

Currently, there is no rate limit for qemu-img convert. This may
cause the task of qemu-img convert to consume all the bandwidth
of the storage. This will affect the IO performance of other processes
and virtual machines under shared storage. So we add support for
offline rate limit in qemu-img convert to get better quality of sevice.

Signed-off-by: Zhengui <[e-mail]>
---
 qemu-img-cmds.hx |  4 ++--
 qemu-img.c       | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 3 deletions(-)

Comments

Alberto Garcia Oct. 19, 2020, 11:45 a.m. UTC | #1

On Sun 18 Oct 2020 08:34:39 AM CEST, Zhengui li wrote:
> @@ -2729,6 +2757,10 @@ out:
>      qemu_opts_del(opts);
>      qemu_opts_free(create_opts);
>      qemu_opts_del(sn_opts);
> +    if (s.target && rate_limit &&
> +        blk_get_public(s.target)->throttle_group_member.throttle_state) {
> +        blk_io_limits_disable(s.target);
> +    }
>      qobject_unref(open_opts);
>      blk_unref(s.target);
>      if (s.src) {

Apart from the comments that I wrote to the other patch, which also
apply to this one, blk_delete() already calls blk_io_limits_disable() so
I don't think you need to do it manually here.

Berto

Eric Blake Oct. 19, 2020, 8:13 p.m. UTC | #2

On 10/18/20 1:34 AM, Zhengui li wrote:
> From: Zhengui <[e-mail]>
> 
> Currently, there is no rate limit for qemu-img convert. This may
> cause the task of qemu-img convert to consume all the bandwidth
> of the storage. This will affect the IO performance of other processes
> and virtual machines under shared storage. So we add support for
> offline rate limit in qemu-img convert to get better quality of sevice.
> 

service

Also, I'd suggest bundling your related patches into a 0/N series (it 
took me a while to notice that you had two separate emails, one for 
commit and one for convert, sent at nearly the same time, because the 
subject line was long enough to truncate the important part in my view-pane)

> Signed-off-by: Zhengui <[e-mail]>
> ---
>   qemu-img-cmds.hx |  4 ++--
>   qemu-img.c       | 34 +++++++++++++++++++++++++++++++++-
>   2 files changed, 35 insertions(+), 3 deletions(-)
>

Patch

diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index ed55b76..70c0bf7 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -46,9 +46,9 @@  SRST
 ERST
 
 DEF("convert", img_convert,
-    "convert [--object objectdef] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")
+    "convert [--object objectdef] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f fmt] [-t cache] [-T src_cache] [-O output_fmt] [-B backing_file] [-o options] [-l snapshot_param] [-S sparse_size] [-r rate_limit] [-m num_coroutines] [-W] [--salvage] filename [filename2 [...]] output_filename")
 SRST
-.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] [--salvage] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
+.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [--bitmaps] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-r RATE_LIMIT] [-m NUM_COROUTINES] [-W] [--salvage] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
 ERST
 
 DEF("create", img_create,
diff --git a/qemu-img.c b/qemu-img.c
index 74e4d64..ffda3c7 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -50,6 +50,8 @@ 
 #include "block/qapi.h"
 #include "crypto/init.h"
 #include "trace/control.h"
+#include "qemu/throttle.h"
+#include "block/throttle-groups.h"
 
 #define QEMU_IMG_VERSION "qemu-img version " QEMU_FULL_VERSION \
                           "\n" QEMU_COPYRIGHT "\n"
@@ -1671,6 +1673,7 @@  enum ImgConvertBlockStatus {
 };
 
 #define MAX_COROUTINES 16
+#define CONVERT_THROTTLE_GROUP "img_convert"
 
 typedef struct ImgConvertState {
     BlockBackend **src;
@@ -2186,6 +2189,17 @@  static int convert_copy_bitmaps(BlockDriverState *src, BlockDriverState *dst)
 
 #define MAX_BUF_SECTORS 32768
 
+static void set_rate_limit(BlockBackend *blk, int64_t rate_limit)
+{
+    ThrottleConfig cfg;
+
+    throttle_config_init(&cfg);
+    cfg.buckets[THROTTLE_BPS_WRITE].avg = rate_limit;
+
+    blk_io_limits_enable(blk, CONVERT_THROTTLE_GROUP);
+    blk_set_io_limits(blk, &cfg);
+}
+
 static int img_convert(int argc, char **argv)
 {
     int c, bs_i, flags, src_flags = 0;
@@ -2206,6 +2220,7 @@  static int img_convert(int argc, char **argv)
     bool force_share = false;
     bool explict_min_sparse = false;
     bool bitmaps = false;
+    int64_t rate_limit = 0;
 
     ImgConvertState s = (ImgConvertState) {
         /* Need at least 4k of zeros for sparse detection */
@@ -2228,7 +2243,7 @@  static int img_convert(int argc, char **argv)
             {"bitmaps", no_argument, 0, OPTION_BITMAPS},
             {0, 0, 0, 0}
         };
-        c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WU",
+        c = getopt_long(argc, argv, ":hf:O:B:Cco:l:S:pt:T:qnm:WUr:",
                         long_options, NULL);
         if (c == -1) {
             break;
@@ -2325,6 +2340,15 @@  static int img_convert(int argc, char **argv)
         case 'U':
             force_share = true;
             break;
+        case 'r': {
+            unsigned long long sval;
+            if (qemu_strtou64(optarg, NULL, 10, &sval)) {
+                error_report("rate limit parse failed");
+                ret = -1;
+                goto fail_getopt;
+            }
+            rate_limit = (int64_t)sval * 1024 * 1024;
+        }   break;
         case OPTION_OBJECT: {
             QemuOpts *object_opts;
             object_opts = qemu_opts_parse_noisily(&qemu_object_opts,
@@ -2714,6 +2738,10 @@  static int img_convert(int argc, char **argv)
         s.cluster_sectors = bdi.cluster_size / BDRV_SECTOR_SIZE;
     }
 
+    if (rate_limit) {
+        set_rate_limit(s.target, rate_limit);
+    }
+
     ret = convert_do_copy(&s);
 
     /* Now copy the bitmaps */
@@ -2729,6 +2757,10 @@  out:
     qemu_opts_del(opts);
     qemu_opts_free(create_opts);
     qemu_opts_del(sn_opts);
+    if (s.target && rate_limit &&
+        blk_get_public(s.target)->throttle_group_member.throttle_state) {
+        blk_io_limits_disable(s.target);
+    }
     qobject_unref(open_opts);
     blk_unref(s.target);
     if (s.src) {