Re: Alan Cox quote? (was: Re: accounting for threads)

george anzinger
2001-06-20T16:43:14Z

Alexander Viro wrote:
>
> On 20 Jun 2001, Jes Sorensen wrote:
>
> > Not to mention how complex it is to get locking right in an efficient
> > manner. Programming threads is not that much different from kernel SMP
> > programming, except that in userland you get a core dump and retry, in
> > the kernel you get an OOPS and an fsck and retry.
>
> Arrgh. As long as we have that "SMP makes locking harder" myth floating
> around we _will_ get problems. Kernel UP programming is not different
> from SMP one. It is multithreaded. And amount of genuine SMP bugs is
> very small compared to ones that had been there on UP since way back.
> And yes, programming threads is the same thing. No arguments here.
>
Correct, IF the UP kernel is preemptable. As long as it is not (and SMP
is ignored) threads are harder BECAUSE they are preemptable.

George