qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH 3/3] disk: don't read from disk until the guest


From: Avi Kivity
Subject: Re: [Qemu-devel] [PATCH 3/3] disk: don't read from disk until the guest starts
Date: Sun, 12 Sep 2010 12:42:36 +0200
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.8) Gecko/20100806 Fedora/3.1.2-1.fc13 Lightning/1.0b2pre Thunderbird/3.1.2

 On 09/11/2010 05:04 PM, Anthony Liguori wrote:
This fixes a couple nasty problems relating to live migration.

1) When dealing with shared storage with weak coherence (i.e. NFS), even if
    we re-read, we may end up with undesired caching.  By delaying any reads
    until we absolutely have to, we decrease the likelihood of any undesirable
    caching.

2) When dealing with copy-on-read, the local storage acts as a cache.  We need
    to make sure to avoid any reads to avoid polluting the local cache.

+
  static void ide_identify(IDEState *s)
  {
      uint16_t *p;
@@ -105,6 +132,8 @@ static void ide_identify(IDEState *s)
        return;
      }

+    guess_geometry(s);
+

This can cause a disk read, no?  Shouldn't it be made asynchronous?

Or just move it to just before the guest starts?

--
error compiling committee.c: too many arguments to function




reply via email to

[Prev in Thread] Current Thread [Next in Thread]