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From: Stefan Hajnoczi <stefanha@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
	"Benoît Canet" <benoit@irqsave.net>,
	"Stefan Hajnoczi" <stefanha@redhat.com>,
	"Zhi Yong Wu" <wuzhy@cn.ibm.com>
Subject: [Qemu-devel] [RFC 4/4] block: clean up I/O throttling wait_time code
Date: Thu, 21 Mar 2013 15:49:59 +0100	[thread overview]
Message-ID: <1363877399-16339-5-git-send-email-stefanha@redhat.com> (raw)
In-Reply-To: <1363877399-16339-1-git-send-email-stefanha@redhat.com>

The wait_time variable is in seconds.  Reflect this in a comment and use
NANOSECONDS_PER_SECOND instead of BLOCK_IO_SLICE_TIME * 10 (which
happens to have the right value).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/block.c b/block.c
index fed3b4d..ff862a0 100644
--- a/block.c
+++ b/block.c
@@ -3698,7 +3698,7 @@ static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors,
                 BLOCK_IO_SLICE_TIME;
     bs->slice_end += extension;
     if (wait) {
-        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+        *wait = wait_time * NANOSECONDS_PER_SECOND;
     }
 
     return true;
@@ -3740,7 +3740,7 @@ static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
         return false;
     }
 
-    /* Calc approx time to dispatch */
+    /* Calc approx time to dispatch, in seconds */
     wait_time = (ios_base + 1) / iops_limit;
     if (wait_time > elapsed_time) {
         wait_time = wait_time - elapsed_time;
@@ -3751,7 +3751,7 @@ static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write,
     /* Exceeded current slice, extend it by another slice time */
     bs->slice_end += BLOCK_IO_SLICE_TIME;
     if (wait) {
-        *wait = wait_time * BLOCK_IO_SLICE_TIME * 10;
+        *wait = wait_time * NANOSECONDS_PER_SECOND;
     }
 
     return true;
-- 
1.8.1.4

  parent reply	other threads:[~2013-03-21 14:50 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-21 14:49 [Qemu-devel] [RFC 0/4] block: fix I/O throttling oscillations Stefan Hajnoczi
2013-03-21 14:49 ` [Qemu-devel] [RFC 1/4] block: fix I/O throttling accounting blind spot Stefan Hajnoczi
2013-03-27  8:50   ` Zhi Yong Wu
2013-03-27  9:14     ` Stefan Hajnoczi
2013-03-27 12:49       ` Zhi Yong Wu
2013-03-21 14:49 ` [Qemu-devel] [RFC 2/4] block: keep I/O throttling slice time constant Stefan Hajnoczi
2013-03-21 14:49 ` [Qemu-devel] [RFC 3/4] block: drop duplicated slice extension code Stefan Hajnoczi
2013-03-21 14:49 ` Stefan Hajnoczi [this message]
2013-03-21 15:27 ` [Qemu-devel] [RFC 0/4] block: fix I/O throttling oscillations Benoît Canet
2013-03-21 16:34   ` Stefan Hajnoczi
2013-03-27 12:55 ` Zhi Yong Wu
2013-04-04 12:15 ` Benoît Canet
2013-04-04 16:24   ` Kevin Wolf
2013-04-04 16:30     ` Stefan Hajnoczi

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