Some additional technical notes on KDE's malloc: Before version 2.3, glibc's malloc implementation guaranteed thread safety in programs linked with lpthread by using a mutex. This is not a bad idea in itself. But it is not the fastest way of locking, which you really notice in applications that use malloc a lot but are not that multi-threaded themselves (like KDE). Doug Lea wrote a really (really) fast malloc implementation (1) that was imported as KDE's malloc by Lubos Lunak (2). They use a spinlock (x86 assembler) as their locking mechanism, which is a lot faster. There are other performance tweaks in it, but all in all there exist as many malloc implementations as opinions out there... ;) This KDE malloc gave a performance gain of about 30% (synthetic benchmark) to about 10% (real world(TM)), so it really was worth it. Glibc 2.3 and up use a spinlock for locking and have received some tuning in their malloc implementation, too (recent glibc's malloc is written by Wolfram Gloger and is based on Doug Lea's malloc, so it is not that different from KDE's malloc right now...) (3). So the performance gain of using KDE's malloc shrinks down to about 5% for glibc 2.3.0 and even less for recent versions. In addition to that: we are using NPTL, which should be quite a bit faster than the old Linux Threads. So although glibc's malloc still has lots of hooks for heavy multi-threading, it should not hurt as much as it did in the past performance-wise. So, to sum it all up: KDE's malloc brought a real performance boost when it was introduced in 2002, but right now, with glibc 2.3 (or 2.4), kernel 2.6 and NPTL, it does not make THAT much of a difference. And if it poses problems (like with glib), it becomes a no-brainer. I know you have already taken it out, this was just a technical comment for some background. ;)
Chris (1) ftp://gee.cs.oswego.edu/pub/misc/ (2) http://lists.kde.org/?l=kde-core-devel&m=101351949010285&w=2 (3) http://www.malloc.de/en/index.html -- http://linuxfromscratch.org/mailman/listinfo/blfs-dev FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page
