On 10/02/2012 09:27 AM, Pierre-Luc Provencal wrote: > Hello, > > I am new at using valgrind. I first tried it on a relatively small program, > and everything worked ok. > > When I try it with a much larger program (19MB), I get a SIGSEGV before the > main() is actually called. It looks like the program crashes while calling in > the constructor functions. This is a 32-bit program run on a CentOs 6.2 > 64-bit system. The system has 8 GB memory. The address that is being used > when the crash occurs is: Access not within mapped region at address > 0xFECB7114. Which is near 4 GB, but should be ok on a 8 GB system.
What is large is not necessarily the 19MB program, but the use of almost 4GiB of address space. 0xFECB7114 is within 20MB or so of the architectural limit on a 32-bit address. In addition to the architectural limit, the software which provides a 32-bit environment on a 64-bit machine imposes an even lower limit on a 32-bit address. There is a large gain in speed if some high 32-bit addresses can be reserved for use by the operating system and libc, instead of making the entire 4GiB range available to the 32-bit "client" (memcheck, including the program being checked.) The reserved amount is at least 256KiB, but might be enough to cover 20MiB, which would tend to explain some of the problems you see. In any case, please run "cat /proc/<PID>/maps" (where <PID> is the numerical process ID) and show us what the mappings look like for addresses 0xFE000000 and above, when the program hits the memcheck error (or shortly before.) -- ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ Valgrind-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/valgrind-users
