Corey, On Fri, Jan 9, 2009 at 1:29 AM, Corey Ashford <cjash...@linux.vnet.ibm.com> wrote: > Hi Stephan, > > As you might have guessed, one of our goals has been to be able to run the > libpfm examples cleanly on Power. > > multiplex.c gives odd error messages about calls to pfm_write_pmds and > pfm_write_pmcs depending on the options given. I tracked this down to the > allocation of the all_pmcs array on line 1146: > > all_pmcs = calloc(1, sizeof(pfarg_pmc_t)*total_events); > Yes, that's way too simplistic. I am not surprised it does not work. It won't even work on Pentium 4.
multiplex.c is a very old program. It was added to demonstrate how one could do user-level multiplexing. Obviously, it needs a serious refresh. As a workaround, we could use pfm_get_num_pmcs() for the multiplier: all_pmcs = calloc(pfm_get_num_pmcs() * num_sets, sizeof(parg_pmc_t)) And do something similar for the other vectors. > The number of PKCs on to allocate on Power is not directly related to the > total events. In this case, there are four total events, but we need 6 pmc > registers (3 for each set). On Power, it's always 3 registers per set. I > would guess that other architectures might have similar issues. > > Because not enough space is allocated, we end up overwriting memory that is > located after the array, causing corruption of memory. This results in > various bad things happening, as you might imagine. > > As a temporary work-around, I changed the multiplier from total_events to > just '20'. This fixed the problem and the test runs correctly, at least > with the default options. > > Any ideas about a better fix than this? > > Regards, > > - Corey > > Corey Ashford > Software Engineer > IBM Linux Technology Center, Linux Toolchain > Beaverton, OR > 503-578-3507 > cjash...@us.ibm.com > > ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB _______________________________________________ perfmon2-devel mailing list perfmon2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/perfmon2-devel
