From: Michael Tokarev <mjt@tls.msk.ru>
To: Avi Kivity <avi@redhat.com>
Cc: KVM list <kvm@vger.kernel.org>
Subject: Re: *terrible* speed of savevm/loadvm/delvm
Date: Sun, 23 Nov 2008 23:08:06 +0300 [thread overview]
Message-ID: <4929B826.1020907@msgid.tls.msk.ru> (raw)
In-Reply-To: <49295FED.9020602@redhat.com>
Avi Kivity wrote:
> Michael Tokarev wrote:
>>>> As you see, it writes 2 bytes, llseeks to THE SAME
>>>> position, writes next 2 bytes and so on. This takes
>>>> HUGE amount of time, and can be done, in most cases,
>>>> in a single write without any seeks.
[]
> Any idea what is happening? Is it disk bound, or cpu bound?
Yes, see above. llseek(curpos)+write(2bytes) - try doing
that for for a more-or-less large file and you'll see ;)
And it seems that this slowness is here for a long time really.
It's just that change in default write/cache mode made the
problem very obvious.
/mjt
prev parent reply other threads:[~2008-11-23 20:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-12 17:15 *terrible* speed of savevm/loadvm/delvm Michael Tokarev
2008-11-13 12:33 ` Avi Kivity
2008-11-20 19:08 ` Michael Tokarev
2008-11-23 13:51 ` Avi Kivity
2008-11-23 20:08 ` Michael Tokarev [this message]
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