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From: Noah Watkins <jayhawk@cs.ucsc.edu>
To: Tommi Virtanen <tommi.virtanen@dreamhost.com>
Cc: Noah Watkins <jayhawk@soe.ucsc.edu>,
	Colin McCabe <cmccabe@alumni.cmu.edu>,
	Mark Kampe <mark.kampe@dreamhost.com>,
	ceph-devel@vger.kernel.org
Subject: Re: towards a user-mode diagnostic log mechanism
Date: Tue, 10 Jan 2012 17:06:55 -0800	[thread overview]
Message-ID: <4F0CE0AF.6090702@cs.ucsc.edu> (raw)
In-Reply-To: <CAORUGqDmT86qdvpba1EYo6_D7KjAm7eHa_hReRgnw0uOU=8HQQ@mail.gmail.com>

On 1/10/12 5:04 PM, Tommi Virtanen wrote:
> On Tue, Jan 10, 2012 at 16:40, Noah Watkins<jayhawk@cs.ucsc.edu>  wrote:
>>
>> Older Linux kernels force a thread into the kernel when calling gettimeofday
>> adding enormous overhead relative to the newer vsyscall implementations that
>> evaluate gettimeofday within userspace.
>
> So turning debug to full blast on older kernels will be painful. I'm
> personally ok with that, especially when the alternative is
> implementing all of the TSC logic myself. This is really complex code,
> and somebody went through the effort of solving the hard problems for

Yeh, that was just a bit of fyi noise.

> us -- let's use their code!

I definitely agree :)

      reply	other threads:[~2012-01-11  1:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-20  2:42 towards a user-mode diagnostic log mechanism Mark Kampe
2011-12-23 10:04 ` Wido den Hollander
2012-01-06  4:09 ` Colin McCabe
2012-01-07  1:46   ` Mark Kampe
2012-01-10  2:20     ` Colin McCabe
2012-01-10 23:25   ` Tommi Virtanen
     [not found]     ` <4F0CDA9A.4070500@cs.ucsc.edu>
2012-01-11  1:04       ` Tommi Virtanen
2012-01-11  1:06         ` Noah Watkins [this message]

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