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Date: Fri, 7 Dec 2012 16:14:40 -0500
From: "Theodore Ts'o" <tytso@mit.edu>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
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Subject: Re: [PATCH, 3.7-rc7, RESEND] fs: revert commit bbdd6808 to fallocate
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On Fri, Dec 07, 2012 at 02:30:19PM -0500, Steven Rostedt wrote:
> How is this similar? By adding this bit, we removed incentive from a
> group of developers that have the means to fix the real issue at hand
> (the performance problem with ext4). Thus, it means that they have a work
> around that's good enough for them, but the rest of us suffer.

That assumes that there **is** a way to claw back the performance
loss, and Chris Mason has demonstrated the performance hit exists with
xfs as well (950 MB/s vs. 400 MB/s; that's more than a factor of two).
Sometimes, you have to make the engineering tradeoffs.  That's why
we're engineers, for goodness sakes.  Sometimes, it's just not
possible to square the circle.

I don't believe that the technique of forcing people who need that
performance to suffer in order to induce them to try to engineer a
solution which may or may not exist is really the best or fairest way
to go about things.

					- Ted