Re: SCO: "thread creation is about a thousand times faster than on native Linux"

From: Andi Kleen (ak@suse.de)
Date: Wed Aug 23 2000 - 12:38:14 EST


On Wed, Aug 23, 2000 at 06:29:28PM +0100, Tigran Aivazian wrote:
> It is plausible that individual _lwp_create(2) is faster than individual
> clone(CLONE_VM) one (possibly between 5x and 10x times, the 1000x figure
> is ridiculous). However, one should look a bit further and ask if native
> kernel-level UW7 lwps are delivering the same set of rich functionality as
> Linux clone'd tasks. IMHO, they simply don't. So one has to add all the
> overhead of turning a "raw" lwp into a useful and useable thread, e.g. as
> used by userspace thread concept. If you do that, no doubt you will find
> that Linux performance is greater than of any commercial alternatives.

The main problem Linux clone has over LWPs is the extensive memory resource
usage (~8.5K on x86, 16+somethingK on 64bit for the kernel stacks)

To solve that it would be very nice to have Mach like continuations in
Linux (multiple kernel threads sharing a kernel stack)

Also the LinuxThreads library does horrible things at pthread_create time,
like doing a full context switch to the manager thread and cloning from
there (mostly to work around signal/waitpid() problems in the kernel)

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Aug 23 2000 - 21:00:09 EST