From: jim owens <jowens@hp.com>
To: Jeff Garzik <jeff@garzik.org>
Cc: linux-raid@vger.kernel.org
Subject: Re: Converting system to raid
Date: Sat, 11 Apr 2009 13:40:30 -0400 [thread overview]
Message-ID: <49E0D60E.7040904@hp.com> (raw)
In-Reply-To: <49E0BAF9.3090209@garzik.org>
Jeff Garzik wrote:
> jim owens wrote:
>> nanosecond time stamps are a myth!
>
> Not true, in the age of NO_HZ...
While nanosecond time is real on some hardware platforms,
I don't know of any hard disk filesystem that does metadata
updates at that level of granularity and guarantees distinct
timestamps between writes at extremely short intervals.
Even SSD performance would suck if we did that.
The filesystem mod-time might have nanoseconds in it, but
that does not mean 2 writes 100 nanoseconds apart will have
different mod-times.
jim
next prev parent reply other threads:[~2009-04-11 17:40 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-09 23:44 Converting system to raid Timothy D. Lenz
2009-04-10 9:10 ` KwangErn Liew
2009-04-10 9:55 ` CoolCold
2009-04-10 19:43 ` Timothy D. Lenz
2009-04-10 19:53 ` Robin Hill
2009-04-10 20:45 ` Timothy D. Lenz
2009-04-10 20:59 ` Robin Hill
2009-04-10 21:26 ` Timothy D. Lenz
2009-04-10 21:51 ` Robin Hill
2009-04-11 5:29 ` Timothy D. Lenz
2009-04-11 14:29 ` CoolCold
2009-04-11 18:47 ` Timothy D. Lenz
2009-04-12 0:53 ` Timothy D. Lenz
2009-04-12 11:11 ` Robin Hill
2009-04-12 19:55 ` Timothy D. Lenz
2009-04-14 9:30 ` Robin Hill
2009-04-17 0:47 ` Timothy D. Lenz
2009-04-17 7:49 ` Robin Hill
2009-04-11 14:36 ` Robin Hill
2009-04-11 15:04 ` jim owens
2009-04-11 15:44 ` Jeff Garzik
2009-04-11 17:40 ` jim owens [this message]
2009-04-12 11:11 ` Jeff Garzik
2009-04-12 16:43 ` jim owens
2009-04-12 17:18 ` Jeff Garzik
2009-04-10 13:22 ` Robin Hill
2009-04-10 19:22 ` Timothy D. Lenz
2009-04-10 19:50 ` Robin Hill
2009-04-11 4:40 ` Jon Lewis
2009-04-11 7:48 ` Jan Ceuleers
2009-04-11 8:50 ` Goswin von Brederlow
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