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From: John Arbuckle <1914667@bugs.launchpad.net>
To: qemu-devel@nongnu.org
Subject: [Bug 1914667] Re: High cpu usage when guest is idle on qemu-system-i386
Date: Fri, 05 Feb 2021 01:40:23 -0000	[thread overview]
Message-ID: <161248922373.2846.17006090225355491407.malone@gac.canonical.com> (raw)
In-Reply-To: 161248158218.12871.10682279346002918371.malonedeb@soybean.canonical.com

For version 5.2 of qemu-system-i386 the instruction the guest is busy
executing over and over again is this: addb %al, (%eax)

For version 2.10.1 this is the instruction that is being executed when the guest is idle:
add %al,(%eax)

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1914667

Title:
  High cpu usage when guest is idle on qemu-system-i386

Status in QEMU:
  New

Bug description:
  When running Windows XP in qemu-system-i386, the cpu usage of QEMU is
  about 100% even when the guest CPU usage is close to 2%. The host cpu
  usage should be low when the guest cpu usage is low.

  Command: qemu-system-i386 -hda <Windows XP HD image>

  Using this command also shows around 100% host CPU usage:
  qemu-system-i386 -m 700 -hda <Windows XP HD image> -usb -device usb-audio -net nic,model=rtl8139 -net user -hdb mountable.img -soundhw pcspk

  Using the Penryn CPU option also saw this problem:
  qemu-system-i386 -hda <Windows XP HD image> -m 700 -cpu Penryn-v1

  Using "-cpu pentium2" saw the same high host cpu usage.

  
  My Info:
  M1 MacBook Air
  Mac OS 11.1
  qemu-system-i386 version 5.2 (1ba089f2255bfdb071be3ce6ac6c3069e8012179)
  Windows XP SP3 Build 2600

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  parent reply	other threads:[~2021-02-05  1:51 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-04 23:33 [Bug 1914667] [NEW] High cpu usage when guest is idle on qemu-system-i386 John Arbuckle
2021-02-05  0:25 ` [Bug 1914667] " John Arbuckle
2021-02-05  1:40 ` John Arbuckle [this message]
2021-02-10 18:50 ` John Arbuckle
2021-02-11  0:09 ` John Arbuckle
2021-05-12 17:59 ` Thomas Huth
2021-07-12  4:17 ` Launchpad Bug Tracker

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