Re: [Valgrind-developers] drd 2007-02-27

[Nicholas N. <nj...@cs...>]

On Tue, 27 Feb 2007, Bart Van Assche wrote:

> A new drd version is available at the following location:
> http://home.euphonynet.be/bvassche/valgrind/valgrind-6618-drd-2007-02-27.patch.gz

Good work :)

> - Started optimizing the bitmap implementation in drd -- drd now works
> several times faster for clients with 10 threads or more. More work
> has to be done in this area however. (Only bm_clear() and
> bm_has_access() have been optimized. According to cachegrind,
> VG_(OSet_Next)() is now the function that consumes most CPU cycles.)

Cachegrind doesn't tell you cycles, only instructions and cache misses. 
Often they correlate to cycles pretty well but not always.

If OSet is too slow, you could try using VgHashTable (see 
pub_tool_hashtable.h).  It has a similar interface and so you might be able 
to switch over easily.  It's faster in some cases, especially for iteration.
Or, you could try to reduce the number of times you iterate over the data 
structure :)

Nick