If you are envisaging to modify valgrind, you could take some inspiration from the way callgrind can dynamically activate/de-activate tracing.
See callgrind manual command line options and client requests for more details Philippe On Wed, 2023-02-08 at 17:47 +1100, Eliot Moss wrote: > On 2/8/2023 4:10 PM, SAI GOVARDHAN M C PES1UG19EC255PESU ECE Student wrote: > > Hi, > > > > We are students working on memory access analysis, using the Lackey tool in > > Valgrind. > > Our memory trace results in a large log file, and we need the trace from > > discrete points of > > execution (between 40-60%). > > Instead of logging completely, and splitting manually, is there a way we > > can modify the Lackey > > command to pick from a desired point in the execution? > > > > For reference, the command we use is > > $ valgrind --tool=lackey --trace-mem=yes --log-file=/path_to_log ./program > > > > We need to modify this to command to trace from 40-60% of the program > > If you know the approximate number of memory accesses, you could do something > as simple as: > > valgrind ... | tail +n XXX | head -n YYY > > to start after XXX lines of output and stop after producing YYY lines. You > could do something more sophisticated using, say, gawk, to trigger on a > particular address being accessed, e.g., as an instruction fetch. > > This will all slow things down a bit, but might accomplish your goals. > > I'm not claiming there isn't some sophisticated way to tell valgrind when > to start tracing, either. Also, nobody is stopping you from customizing > the tool yourself :-) ... a mere exercise in programming, no? > > Best wishes - EM > > > _______________________________________________ > Valgrind-users mailing list > Valgrind-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/valgrind-users _______________________________________________ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
