Re: [PATCH] Put sha1dc on a diet

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 1, 2017, 21:56 UTC
Message-ID: <alpine.DEB.2.20.1703012227010.3767@virtualbox>
In-Reply-To: <xmqq37ewhji1.fsf@gitster.mtv.corp.google.com>

Hi,

On Wed, 1 Mar 2017, Junio C Hamano wrote:

Show 7 quoted lines

> Linus Torvalds <torvalds@linux-foundation.org> writes:
> 
> > That said, I think that it would be lovely to just default to
> > USE_SHA1DC and just put the whole attack behind us. Yes, it's slower.
> > No, it doesn't really seem to matter that much in practice.
> 
> Yes.  It would be a very good goal.

So let me get this straight: not only do we now implicitly want to bump the required C compiler to C99 without any grace period worth mentioning [*1*], we are also all of a sudden no longer worried about a double digit percentage drop of speed [*2*]?

Puzzled, Johannes

Footnote *1*: I know, it is easy to forget that some developers cannot choose their tools, or even their hardware. In the past, we seemed to take appropriate care, though.

Footnote *2*: With real-world repositories of notable size, that performance regression hurts. A lot. We just spent time to get the speed of SHA-1 down by a couple percent and it was a noticeable improvement here.