lkml.org 
[lkml]   [2006]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: 2048 CPUs [was: Re: New filesystem for Linux]
Hi!

> >>If some rogue threads (and it may not even be intetional) call the same
> >>syscall stressing the one spinlock all the time, other syscalls needing
> >>the same spinlock may stall.
> >
> >Fortunately, they'll unstall with probability of 1... so no, I do not
> >think this is real problem.
>
> You can't tell that CPUs behave exactly probabilistically --- it may
> happen that one gets out of the wait loop always too late.

Well, I don't need them to be _exactly_ probabilistical.

Anyway, if you have 2048 CPUs... you can perhaps get some non-broken
ones.

> >If someone takes semaphore in syscall (we do), same problem may
> >happen, right...? Without need for 2048 cpus. Maybe semaphores/mutexes
> >are fair (or mostly fair) these days, but rwlocks may not be or
> >something.
>
> Scheduler increases priority of sleeping process, so starving process
> should be waken up first. But if there are so many processes, that
>process

I do not think this is how Linux scheduler works.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-11-10 10:05    [W:4.619 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site