From: Tim Chen <tim.c.chen@linux.intel.com>
To: Jeremy Fitzhardinge <jeremy@goop.org>, zach@vmware.com
Cc: Virtualization Mailing List <virtualization@lists.osdl.org>,
linux-kernel@vger.kernel.org
Subject: Re: system call time increase when turning on CONFIG_PARAVIRT
Date: Wed, 07 Mar 2007 16:02:04 -0800 [thread overview]
Message-ID: <1173312124.8383.35.camel@localhost.localdomain> (raw)
In-Reply-To: <45E8BE79.40200@goop.org>
On Fri, 2007-03-02 at 16:16 -0800, Jeremy Fitzhardinge wrote:
>
> Yes, the intent is that running a CONFIG_PARAVIRT kernel on native
> hardware will have negligible performance hit compared to running a
> non-paravirt kernel.
>
> J
It turned out that VDSO was turned off by CONFIG_PARAVIRT option,
causing the system call to use inefficient int 0x80 which led to the
increase system_call time I was seeing. I noted that Ingo has caught
this problem and proposed a patch to correct this issue in another mail
thread.
Tim
next prev parent reply other threads:[~2007-03-08 0:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1172866274.4898.14.camel@localhost.localdomain>
2007-03-02 21:54 ` system call time increase when turning on CONFIG_PARAVIRT Jeremy Fitzhardinge
2007-03-02 23:11 ` Tim Chen
2007-03-03 0:16 ` Jeremy Fitzhardinge
2007-03-03 7:00 ` Zachary Amsden
2007-03-08 0:02 ` Tim Chen [this message]
2007-03-08 0:55 ` Jeremy Fitzhardinge
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