|
From: Yeshurun, M. <mei...@in...> - 2005-08-07 09:07:34
|
Hi, I've been using a PIE build of Valgrind 3.0 on a 64 bit platform. So far it's working great, and the extra virtual memory is a life saver. I have just two small questions: 1. Is it normal for a PIE build to be slower? 2. Is it normal for a PIE build to allocate a huge amount of virtual memory (270G) even when running on tiny programs? (I don't really mind, but the Linux administrators made me swear that I would ask you, so please just say yes :) Thanks, Meir -----Original Message----- From: val...@li... [mailto:val...@li...] On Behalf Of Nicholas Nethercote Sent: Friday, August 05, 2005 6:58 PM To: Valgrind Users Subject: [Valgrind-users] Clarification about --enable-pie/--disable-pie Hi, In Valgrind 2.4.0, we built Valgrind as a position-independent executable=20 (PIE) if the toolchain supported it. This turned out to cause quite a few=20 problems -- people having random, inexplicable crashes. So for 3.0.0 we turned it off by default because it was causing too many problems. As a result of all this, it unfortunately seems like=20 --enable-pie/--disable-pie has taken on a mythical status... as though we=20 deliberately shipped a crippled Valgrind and you have to find the special=20 configure option to get it to work, bwaha! So I'm trying to clear up the confusion. Here's a summary: - 3.0.0 does not use PIE by default. This is much more stable. Do not use --enable-pie unless you have to. - Any why would you have to? Because a PIE build can give your program more address space when running under Valgrind, particularly on AMD64. - However, as we have seen, using PIE is a bit flaky and has caused problems on many systems. In short: don't use --enable-pie when configuring Valgrind unless you=20 know you need the extra address space it allows. And if you do use it,=20 don't be shocked if Valgrind crashes. We'd like to fix these problems, but we don't understand them yet. Any=20 information people can shed on them would be great, but as usual, saying "I built with PIE and Valgrind crashes!! What's wrong??" isn't very=20 helpful. The more relevant information you can provide, the better. N ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Valgrind-users mailing list Val...@li... https://lists.sourceforge.net/lists/listinfo/valgrind-users |