On Tue, Aug 18, 2009 at 7:18 AM, Peng Du<imdup...@gmail.com> wrote: > Hello, everyone > > A newbie question, according to Valgrind's manual for the lackey tool: > > "It (lackey) could be made to run a lot faster by doing a slightly more > sophisticated job of the instrumentation ..." > > Now I need a very simple memory read/write counting tool, just like > lackey. But the tool has to be fast. > > Can anyone elaborate a little on how to make lackey A LOT FASTER? Or > has anyone done so? If yes, do you mind sharing the source?
I see two possibilities: - Currently there is one C function call per original instruction. You could batch these up to a degree, eg. count multiple instructions with a single C function call. Cachegrind does something like this. - You could use inline (Vex IR) instrumentation rather than C function calls. See VEX/pub/libvex_ir.h for details of Vex IR. You could also do both of these together. Doing so is left as an exercise to the reader. Even if you do all that, the tool would still have a significant slowdown -- the limit case is Nulgrind (--tool=none) which does no instrumentation and typically has a 5x slow-down. I don't know if that is fast enough for your purposes. You could look at Pin or DynamoRIO as alternative instrumentation frameworks that are better suited to simple tools such as the one you need. Pin in particular may have such a tool included in its distribution. Or you could look at hardware program counters, if they provide the information you need. Nick ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
