From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicolas Pitre <nico@fluxnic.net>
Subject: Re: [PATCH 1/2] index-pack: smarter memory usage when resolving deltas
Date: Mon, 12 Apr 2010 11:45:24 -0400 (EDT)
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Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
To: Johannes Sixt <j.sixt@viscovery.net>
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On Mon, 12 Apr 2010, Johannes Sixt wrote:

> Am 4/12/2010 4:57, schrieb Nicolas Pitre:
> > --- a/builtin/index-pack.c
> > +++ b/builtin/index-pack.c
> > @@ -359,34 +359,33 @@ static void *get_data_from_pack(struct object_entry *obj)
> >  {
> >  	off_t from = obj[0].idx.offset + obj[0].hdr_size;
> >  	unsigned long len = obj[1].idx.offset - from;
> > -	unsigned long rdy = 0;
> > -	unsigned char *src, *data;
> > +	unsigned char *data, inbuf[4096];
> 
> With this tiny buffer we make way more pread() calls than we used to,
> right? This hurts emulated pread(), where we do at least 4 syscalls per
> pread(). Shouldn't the buffer be much larger, like min(len,16*4096)?

Well, that is certainly a good compromize.  The buffer would need to be 
malloc()'d and free()'d again though.


Nicolas