Re: [PATCH 2/2] Implement a simple delta_base cache

On Sat, 17 Mar 2007, Morten Welinder wrote:

quoted

        samples  %        app name                 symbol name
        41527    15.6550  git                      strlen

Almost 16% in strlen?  Ugh!

That's a lot of strings, or perhaps very long strings.  Or a profiling bug.

It's likely real, and the problem is likely lots of small strings.

Each git tree entry is:

	"<octal mode> name\0" <20-byte sha1>

so you do have a *lot* of strlen() calls when doing any tree parsing. And 
for some inexplicable reason, glibc thinks strings are long on average, so 
it has a fancy algorithm to do 8 bytes at a time and tries to do things 
aligned etc.

The size of strlen() on x86-64 with glibc is 232 bytes. I'm not kidding.

			Linus