Hi, On Thu, 02 Feb 2006 15:40:39 -0500 fire-eyes <[EMAIL PROTECTED]> wrote:
> Myself I tried ntpl (and also ntplonly at someones suggestion). It is > supposed to offer better thread support, especially if you have an SMP > or dual core system. I have an SMP system. It's just more lightweight by using (more) kernel mechanisms. It leverages the binding between threads and processes. This of course means that one can only profit if one uses multithreading apps. > Maybe it was just for me, but this turned into a total disaster. I later > found that it was due to setting ntplonly, which apparently disables > old, non-ntpl support entirely. Which is very very bad for apps that > don't yet support ntpl, or something like that. Well, it's bad for apps that weren't compiled with nptl support. Usually, there's not much that keeps an app utilizing the old linuxthreads from using NPTL instead. But due to this being part of glibc, it obviously doesn't work for programs linked statically or against an older glibc. > My suggestion is to talk to gentoo devs, and decide for yourself if you > think it's worth it. And by all means stay away from ntplonly. I'm doing fine with nptlonly for some years now. (not *that* many years, of course :-) > Today my system is ntpl (without ntplonly), on an SMP system, and I > don't notice any improvement at ALL. Which is VERY annoying considering > the complete insanity I went through for about a week. Well, maybe you aren't using multithreaded apps? Or the threading overhead is neglegible? For me it makes a huge difference on my pentium-200mmx (yes...) running VDR (my mediacenter-box), which is heavily threaded. All other apps I'm using don't use threads (in fact, some do but arre using more high-level threading implementations aside from linuxthreads and NPTL). Lots of apps I'm using are still just forking processes and talking via IPC. > Yes, I know only some apps support ntpl, but the impression given to me > was that it would speed up the whole system. Which is certainly not true. OK, but that was a too high expectation. It's never been advertised as high-performance general tool. And since you knew there are only some apps making profit of threads, you should have known that the effect was likely to be small. I can recommend NPTL for situations where threading really matters. And it only speeds threading, so whether using it or not is a matter of analyzing your application landscape... BTW, I don't suggest switching to NPTL either. If one starts a new Gentoo installation, I think it would be a good idea to use NPTL right from the start (and even try nptlonly). Switching from linuxthreads to nptlonly brings some risks mentioned above. So a "emerge -e world" may be a good idea in the case one goes down that road. -hwh -- gentoo-user@gentoo.org mailing list
