Subject: Re: Linux RT signals emulation (PowerPC vs i386)
To: Emmanuel Dreyfus <p99dreyf@criens.u-psud.fr>
From: Jaromír <jdolecek@netbsd.org>
List: tech-kern
Date: 03/18/2001 16:54:17
Emmanuel Dreyfus wrote:
> Hence the question: do NetBSD/i386 make any use of Linux RT signals? It
> seems to me that it does treat all signals as been standards signals,
> not RT signals. If this is true, is it because of the lack of RT signals
> support from NetBSD? And it seems that NetBSD/i386 emulation is able to
> run Linux's JDK-1.3.0, hence emulation of RT signals as standard signals
> does not seems to be a real problem. Is it? I remember I've readen
> something like glibc does not use RT signal because of the kernel
> version returned by emulated uname(). Is it true? (ie: does Linux i386
> binaries avoid using RT signals on NetBSD because of the kernel version
> returned by uname?)

Yeah, Linux RT signals are not really supported on NetBSD.

You are right about the uname thing; glibc/linuxthreads won't use rt
signals unless kernel version is >= 2.1.70 (NetBSD fakes version
2.0.38), see glibc/sysdeps/unix/sysv/linux/testrtsig.h:kernel_has_rtsig() and
glibc/linuxthreads/pthread.c:init_rtsigs().

So yes, linuxthreads should not use RT signals on NetBSD. Some RT stubs
may be still be necessary probably, however.

Jaromir
-- 
Jaromir Dolecek <jdolecek@NetBSD.org>      http://www.ics.muni.cz/~dolecek/
 ***  Wanna a real operating system ? Go and get NetBSD, dammit!  ***