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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] [PATCH v2 3/4] block: drop duplicated slice extension code
Date: Fri,  5 Apr 2013 11:32:21 +0200	[thread overview]
Message-ID: <1365154342-10513-4-git-send-email-stefanha@redhat.com> (raw)
In-Reply-To: <1365154342-10513-1-git-send-email-stefanha@redhat.com>

The current slice is extended when an I/O request exceeds the limit.
There is no need to extend the slice every time we check a request.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-By: Benoit Canet <benoit@irqsave.net>
---
 block.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 00eca27..aa16fc4 100644
--- a/block.c
+++ b/block.c
@@ -3867,10 +3867,7 @@ static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors,
     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 {
+    if (now > bs->slice_end) {
         bs->slice_start = now;
         bs->slice_end   = now + BLOCK_IO_SLICE_TIME;
         memset(&bs->slice_submitted, 0, sizeof(bs->slice_submitted));
-- 
1.8.1.4

  parent reply	other threads:[~2013-04-05  9:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-05  9:32 [Qemu-devel] [PATCH v2 0/4] block: fix I/O throttling oscillations Stefan Hajnoczi
2013-04-05  9:32 ` [Qemu-devel] [PATCH v2 1/4] block: fix I/O throttling accounting blind spot Stefan Hajnoczi
2013-04-05  9:32 ` [Qemu-devel] [PATCH v2 2/4] block: keep I/O throttling slice time constant Stefan Hajnoczi
2013-04-05  9:32 ` Stefan Hajnoczi [this message]
2013-04-05  9:32 ` [Qemu-devel] [PATCH v2 4/4] block: clean up I/O throttling wait_time code Stefan Hajnoczi
2013-04-05 12:32 ` [Qemu-devel] [PATCH v2 0/4] block: fix I/O throttling oscillations Kevin Wolf

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