Re: Questions on GSoC 2019 Ideas

[Thomas Gummerer <t.gummerer@gmail.com>]

On 03/01, Duy Nguyen wrote:
> On Fri, Mar 1, 2019 at 5:20 AM Christian Couder
> <christian.couder@gmail.com> wrote:
> >
> > Hi Matheus,
> >
> > On Thu, Feb 28, 2019 at 10:46 PM Matheus Tavares Bernardino
> > <matheus.bernardino@usp.br> wrote:
> > >
> > > I've been in the mailing list for a couple weeks now, mainly working
> > > on my gsoc micro-project[1] and in other patches that derived from it.
> > > I also have been contributing to the Linux Kernel for half an year,
> > > but am now mainly just supporting other students here at USP.
> > >
> > > I have read the ideas page for the GSoC 2019 and many of them interest
> > > me. Also, looking around git-dev materials on the web, I got to the
> > > GSoC 2012 ideas page. And this one got my attention:
> > > https://github.com/peff/git/wiki/SoC-2012-Ideas#improving-parallelism-in-various-commands
> > >
> > > I'm interested in parallel computing and that has been my research
> > > topic for about an year now. So I would like to ask what's the status
> > > of this GSoC idea. I've read git-grep and saw that it is already
> > > parallel, but I was wondering if there is any other section in git in
> > > which it was already considered to bring parallelism, seeking to
> > > achieve greater performance. And also, if this could, perhaps, be a
> > > GSoC project.
> >
> > I vaguely remember that we thought at one point that all the low
> > hanging fruits had already been taken in this area but I might be
> > wrong.
> 
> We still have to remove some global variables, which is quite easy to
> do, before one could actually add mutexes and stuff to allow multiple
> pack access. I don't know though if the removing global variables is
> that exciting for GSoC, or if both tasks could fit in one GSoC. The
> adding parallel access is not that hard, I think, once you know
> packfile.c and sha1-file.c relatively well. It's mostly dealing with
> caches and all the sliding access windows safely.

I'm not very familiar with what's required here, but reading the above
makes me think it's likely too much for a GSoC project.  I think I'd
be happy with a project that declares removing the global variables as
the main goal, and adding parallelism as a potential bonus.

I'm a bit wary of a too large proposal here, as we've historically
overestimated what kind of project is achievable over a summer (I've
been there myself, as my GSoC project was also more than I was able to
do in a summer :)).  I'd rather have a project whose goal is rather
small and can be expanded later, than having something that could
potentially take more than 3 months, where the student (or their
mentors) have to finish it after GSoC.

> -- 
> Duy