<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Dec 12, 2012, at 10:07 AM, Jason Evans <<a href="mailto:jasone@canonware.com">jasone@canonware.com</a>> wrote:</div><blockquote type="cite">On Dec 12, 2012, at 10:01 AM, Daniel Mezzatto Rodrigues <<a href="mailto:danielm@buscape-inc.com">danielm@buscape-inc.com</a>> wrote:<br><blockquote type="cite">Configuring jemalloc with --enable-munmap made valgrind error messages vanish! No more error messages as far as I could test.<br><br>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?<br></blockquote><br>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.<br><br><blockquote type="cite">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?<br></blockquote><br>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.<br></blockquote><div><br></div>If you want to be totally sure that the fix is correct, you can apply the following and test without the --enable-munmap option:</div><div><br></div><div><span class="Apple-tab-span" style="white-space:pre"> </span><a href="http://www.canonware.com/cgi-bin/gitweb.cgi?p=jemalloc.git;a=commitdiff;h=1271185b87fcf54afb37dc05e7e0c58e5fb8f06a">http://www.canonware.com/cgi-bin/gitweb.cgi?p=jemalloc.git;a=commitdiff;h=1271185b87fcf54afb37dc05e7e0c58e5fb8f06a</a></div><div><br></div><div>Thanks,</div><div>Jason</div></body></html>