Re: [PATCH] Put sha1dc on a diet

[Junio C Hamano <gitster@pobox.com>]

On Wed, Mar 1, 2017 at 1:56 PM, Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Wed, 1 Mar 2017, Junio C Hamano wrote:
>
>> 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*]?

Before we get the code into shape suitable for 'next', it is more important to
make sure it operates correctly, adding necessary features if any (e.g. "hash
with or without check" knob) while it is in 'pu', and *1* is to allow
it to progress
faster without having to worry about something we could do mechanically
before making it ready for 'next'.

The performance thing is really "let's see how well it goes". With effort to
optimize still "just has began", I think it is too early to tell if
Linus's "doesn't
really seem to matter" is the case or not.

Queuing such a topic on 'pu' is one effective way to make sure people are
working off of the same codebase.