Re: [RFD PATCH 0/3] Free all the memory!

From: Eric Wong <e@80x24.org>
Date: May 18, 2016, 07:23 UTC
Message-ID: <20160518072329.GA1723@dcvr.yhbt.net>
In-Reply-To: <CAGZ79kaJoAxqtsTuErQSgJiVeD_vdZ1MQXKr-LTtyro-FbscTQ@mail.gmail.com>

Stefan Beller <sbeller@google.com> wrote:

Show 7 quoted lines

> Eric Wong writes:
> > I haven't checked for git, but I suspect we get speedups by not
> > calling free().  I've never needed to profile git, but free() at
> > exit has been a measurable bottleneck in other projects I've
> > worked on.  Often, free() was more expensive than *alloc().
> 
> Thanks for reiterating that original response I got back then :)

Heh, I suspected I missed some of the original discussion.

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> > #ifdef FREE_ALL_MEMORY
> > static inline void optional_free(void *ptr) {}
> > #else
> > #  define FREE_ALL_MEMORY (0)
> > #  define optional_free(ptr) free(ptr)
> > #endif
> 
> Shouldn't that be "#ifndef" instead? I really like the
> "optional_free", I'll keep it in mind!

Yes, I got my conditionals backwards. That's what I get for being awake way past my bedtime :x

We may also want to find a way to annotate *alloc calls as "lifetime" so they can pair with optional_free. Maybe sparse can help with that?