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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Nicolas Pitre <nico@cam.org>
Cc: "Shawn O. Pearce" <spearce@spearce.org>,
	Junio C Hamano <junkio@cox.net>,
	git@vger.kernel.org
Subject: Re: [PATCH] Limit the size of the new delta_base_cache
Date: Mon, 19 Mar 2007 10:07:43 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.64.0703191004560.6730@woody.linux-foundation.org> (raw)
In-Reply-To: <alpine.LFD.0.83.0703191218190.18328@xanadu.home>



On Mon, 19 Mar 2007, Nicolas Pitre wrote:
> 
> In fact, the bigger is the object, the more effective will be the cache.  

Yes. BUT ONLY IF THE CACHE ISN'T SIZE-LIMITED!

Once you limit the size of the cache, you change the whole equation.

It's usually *more* expensive to re-parse two half-sized objects than it 
is to parse one large object. So if you have to choose between 
throwing out two small objects or throwing out one large one, you 
should choose the single large one.

Which totally throws your argument out of the window. It's simply not true 
any more: the cache will *not* be more effective the larger the objects 
are, because you are ignoring the fact that adding a large object will 
*remove* many small ones.

So if I were Junio, I wouldn't accept your patch as it is now. Your 
argument is simply fundamentally flawed.

		Linus

  parent reply	other threads:[~2007-03-19 17:08 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-19  5:14 [PATCH] Limit the size of the new delta_base_cache Shawn O. Pearce
2007-03-19 16:10 ` Linus Torvalds
2007-03-19 16:41   ` Nicolas Pitre
2007-03-19 16:54     ` Nicolas Pitre
2007-03-19 17:18       ` Linus Torvalds
2007-03-19 17:07     ` Linus Torvalds [this message]
2007-03-19 17:17       ` Linus Torvalds
2007-03-19 18:08         ` Nicolas Pitre
  -- strict thread matches above, loose matches on Subject: below --
2007-03-19  4:48 Shawn O. Pearce

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