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From: =?iso-8859-1?Q?Michael_Gr=F8nager?= <gronager@ceptacle.com>
In-Reply-To: <CAAS2fgQ+zc_ji+8hzA8kvfBPTSpYVEsDSB6=6k8cC6R9vdfcdg@mail.gmail.com>
Date: Wed, 1 Feb 2012 16:50:46 +0100
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	<CAAS2fgQ+zc_ji+8hzA8kvfBPTSpYVEsDSB6=6k8cC6R9vdfcdg@mail.gmail.com>
To: Gregory Maxwell <gmaxwell@gmail.com>
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Announcement: libcoin
Precedence: list

Hi Gregory,

I played with the database sync as well to get further speedups, but in =
the latest version I could only get about 1% extra from this.=20

In the Satoshi client there is a bunch of sleeps and mutexes (put in =
there with great generosity)  for making threads run smoother and to =
avoid deadlock I guess.

The big change in speed came from moving from the threading based setup =
to the async based setup, so I think these are the culprit. Further, as =
I also write somewhere in the wiki. I can measure that 50% of the time =
is consumed in verify, so there is not much left to optimize now. =
Actually, Berkeley DB does a quite decent job in caching reads so not =
even a cache should help.

Cheers,

M

On 01/02/2012, at 15:59, Gregory Maxwell wrote:

> On Wed, Feb 1, 2012 at 9:18 AM, Michael Gr=F8nager =
<gronager@ceptacle.com> wrote:
>> The libcoin/bitcoind client downloads the entire block chain 3.5 =
times faster than the bitcoin/bitcoind client. This is less than 90 =
minutes on a modern laptop!
>=20
> Very interesting. Do you know where this speedup came from?  It's not
> typical for straight refactors that don't change datastructures and
> the like to see such big speedups.
>=20
> I see you have commented out code that disables fsync, which was my
> first guess since I get big speedups from doing similar things.

Michael Gronager, PhD
Director, Ceptacle
Jens Juels Gade 33
2100 Copenhagen E
Mobile: +45 31 45 14 01
E-mail: gronager@ceptacle.com
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