Re: Performance issue of 'git branch'

On Sun, 26 Jul 2009, Johannes Schindelin wrote:

quoted

It seems to come from libcrypto. I can get rid of it with NO_OPENSSL, and 
that cuts down on the number of system calls in my startup by 16 (getting 
rid of both libcrypto and libdl). I wonder if there is some way to get the 
optimized openssl sha1 routines _without_ that silly ldl thing.

OpenSSL allows for so-called engines implementing certain algorithms.  
These engines are dynamic libraries, loaded via dlopen().

Ah. Ok, that explains it.

It's a bit sad, since the _only_ thing we load all of libcrypto for is the 
(fairly trivial) SHA1 code. 

But at the same time, last time I benchmarked the different SHA1 
libraries, the openssl one was the fastest. I think it has tuned assembly 
language for most architectures. Our regular mozilla-based C code is 
perfectly fine, but it doesn't hold a candle to assembler tuning.

Oh well. 

		Linus