commit 2024c1df43eae0d2e35663da0c6e8c51290a386e
author Benoît Canet <benoit@irqsave.net> Mon Sep 02 14:14:41 2013 +0200
committer Stefan Hajnoczi <stefanha@redhat.com> Fri Sep 06 15:25:07 2013 +0200
tree fb92213d73ab06a296a0c83797735cd66aae1674
parent 3e9fab690d59ac15956c3733fe0794ce1ae4c4af

block: Add iops_size to do the iops accounting for a given io size.

This feature can be used in case where users are avoiding the iops limit by
doing jumbo I/Os hammering the storage backend.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

blockdev.c

diff --git a/blockdev.c b/blockdev.c
index 76e9308..fe2f318 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -507,7 +507,7 @@
     cfg.buckets[THROTTLE_OPS_WRITE].max =
         qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
 
-    cfg.op_size = 0;
+    cfg.op_size = qemu_opt_get_number(opts, "throttling.iops-size", 0);
 
     if (!check_throttle_config(&cfg, &error)) {
         error_report("%s", error_get_pretty(error));
@@ -774,6 +774,9 @@
     qemu_opt_rename(all_opts, "bps_rd_max", "throttling.bps-read-max");
     qemu_opt_rename(all_opts, "bps_wr_max", "throttling.bps-write-max");
 
+    qemu_opt_rename(all_opts,
+                    "iops_size", "throttling.iops-size");
+
     qemu_opt_rename(all_opts, "readonly", "read-only");
 
     value = qemu_opt_get(all_opts, "cache");
@@ -1273,7 +1276,9 @@
                                bool has_iops_rd_max,
                                int64_t iops_rd_max,
                                bool has_iops_wr_max,
-                               int64_t iops_wr_max, Error **errp)
+                               int64_t iops_wr_max,
+                               bool has_iops_size,
+                               int64_t iops_size, Error **errp)
 {
     ThrottleConfig cfg;
     BlockDriverState *bs;
@@ -1312,7 +1317,9 @@
         cfg.buckets[THROTTLE_OPS_WRITE].max = iops_wr_max;
     }
 
-    cfg.op_size = 0;
+    if (has_iops_size) {
+        cfg.op_size = iops_size;
+    }
 
     if (!check_throttle_config(&cfg, errp)) {
         return;
@@ -2038,6 +2045,10 @@
             .type = QEMU_OPT_NUMBER,
             .help = "total bytes write burst",
         },{
+            .name = "throttling.iops-size",
+            .type = QEMU_OPT_NUMBER,
+            .help = "when limiting by iops max size of an I/O in bytes",
+        },{
             .name = "copy-on-read",
             .type = QEMU_OPT_BOOL,
             .help = "copy read data from backing file into image file",