[Savannah-hackers-public] Re: [sr #107505] Please reduce gnash git repo size

[Jim Meyering]

Sylvain Beucler wrote:
> On Mon, Oct 25, 2010 at 10:44:00PM +0200, Jim Meyering wrote:
>> Sylvain Beucler wrote:
>>
>> > On Mon, Oct 25, 2010 at 10:30:13PM +0200, Jim Meyering wrote:
>> >> Sylvain Beucler wrote:
>> >> > Do you know about concurrency?  I.e. need we make the repo read-only
>> >> > for developers when we're doing such a repack?
>> >>
>> >> >From what I recall, that's not necessary.
>> >> I think (probably a gross simplification) it creates a big pack of
>> >> whatever's on hand, and then flips a ref (atomic rename) to make the new
>> >> pack's objects live, and then removes the packed (and now logically
>> >> unlinked) objects at its leisure. Any new objects that came in while
>> >> packing are simply not packed.
>> >
>> > I guess I'll try on a copy of the Gnash repo.
>> >
>> > It seems there's some kind of special condition in that project
>> > though, I don't get nearly the same ratio on my projects (admittedly
>> > not nearly as active either :)).
>>
>> Those numbers are typical of a large project that's been converted from
>> e.g., cvs, and whose repository has never been properly compressed.
>
> I committed during various phases of the 'gc' (counting, compressing,
> writing), all the commits were kept, just not packed.
>
> I'll optimize the real gnash.git right now - lots of b/w saved :)

Beware that if you use pack.threads=0 or a value that's too large,
repacking that repo may run out of memory.  When I did it on an 8-core
system with 4GiB of RAM, it failed until I limited it to 2 cores.

> Speaking of git, there are messages from cvs2git piling up in the mail
> system, due to no alias defined for cvs2git, which is now done.  I
> think you disabled the emacs cvs->git repo but not the cron.

Thanks for the heads up.  I've just turned that off.