Re: [RFC, PATCH 1/3] introduce SYS_CLONE_MASK

Robin Holt
2007-04-09T17:31:04Z

OK. I just got the OK from management. The system we were booting was
for research only. We had NR_CPUS=num_online_cpus()=4096 which were
non-hyperthreaded. With no attached I/O and the tweak I originally
posted plus one change Jack has already gotten accepted, the machine
booted in approx 12 minutes.

Thanks,
Robin

On Mon, Apr 09, 2007 at 10:20:27AM -0600, Eric W. Biederman wrote:
> Roland McGrath <roland@redhat.com> writes:
>
> > I concur with Eric's assessment. Adding new magic bits to the generic
> > clone path seems like a poor way to cope with kernel threads. I think
> > it's better if kernel thread setup gets less like normal user process
> > setup. I also agree with Eric that PPID of 0 is a very natural way for
> > kernel threads to be displayed. We need to know more about the nature
> > of the compatibility issue in procps to judge whether there is good
> > reason to avoid changing it.
>
> I just investigated the procps issue. Using init_task as the parent
> nothing sticks out as being wrong in /proc.
>
> Further when I modified pstree to accept 0 as it's starting pid (from
> which all else would be rooted). All of the kernel threads showed up.
>
> So if anything I it is a feature that kernel threads don't show up
> by default in pstree (when PPID == 0). It isn't a subtle kernel bug.
>
> Eric