Messages in this thread | | | Date | 24 Aug 2000 20:18:00 +0200 | From | (Kai Henningsen) | Subject | Re: SCO: "thread creation is about a thousand times faster than onnati |
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yodaiken@fsmlabs.com wrote on 23.08.00 in <20000823172504.A733@hq.fsmlabs.com>:
> On Wed, Aug 23, 2000 at 10:54:57PM +0200, Andi Kleen wrote: > > The users do not distingush between kernel thread and thread. They just > > want a thread and assume it is lightweight. Linux effectively gives them > > only heavy threads currently, which they usually do not need. > > Linux processes are more lightweight than "threads" on many operating > systems. As Rob Pike pointed out many years ago: a perceived need for > "threads" means that processes are poorly designed.
*Only* if the perceived need comes from performance issues.
Threads are a rather nice programming abstraction *if used right*, and processes (i.e. threads without shared memory) certainly aren't a reasonable replacement, just as you wouldn't want to replace subroutines with processes.
In *this* role, performance is a rather secondary issue (unless it's abysmally bad).
Coroutines can do a lot of this, but as soon as you have hard-to-predict scheduling, or want to block on system calls, you want real threads, not coroutines.
MfG Kai - 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/
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