On Dec 12, 2012, at 10:01 AM, Daniel Mezzatto Rodrigues <[email protected]> wrote: > Configuring jemalloc with --enable-munmap made valgrind error messages > vanish! No more error messages as far as I could test. > > Are there any disadvantages of using --enable-munmap? I see that it enables > virtual memory deallocation via munmap. It seens that it was enabled by > default in previous version of jemalloc. Is that correct?
The disadvantage of using --enable-munmap on Linux is that the kernel's heuristics for finding available virtual memory are quite naive, and they routinely result in virtual memory map fragmentation. That wouldn't be a big deal, except that the kernel also uses linear VM map searches for some common operations, so performance can suffer badly for large-memory applications. > Will you change this VALGRIND_MAKE_MEM_UNDEFINED() call in chunk_recycle() so > that configuring jemalloc with --enable-munmap won't be in future versions? Yes, I will fix chunk_recycle() and include the fix in the next jemalloc release. Thank you for your bug report and help in diagnosing the cause. Jason _______________________________________________ jemalloc-discuss mailing list [email protected] http://www.canonware.com/mailman/listinfo/jemalloc-discuss
