Messages in this thread | | | Date | Fri, 12 Oct 2007 21:34:36 -0400 | From | Gustavo Chain <> | Subject | Re: [PATCH] Reserve N process to root |
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El Fri, 12 Oct 2007 09:29:10 +0300 Al Boldi <a1426z@gawab.com> escribió:
> Kyle Moffett wrote: > > On Oct 12, 2007, at 01:37:23, Al Boldi wrote: > > > You have a point, and resource-controllers can probably control > > > DoS a lot better, but the they also incur more overhead. Think > > > of this "lockout prevention" patch as a near zero overhead safety > > > valve. > > > > But why do you need to add "lockout prevention" if it already > > exists? > > I said this before, but I'll say it again: it's about overhead! > > > With CFS' extremely efficient per-user-scheduling (hopefully > > soon to be the default) there are only two forms of lockout by non- > > root processes: (1) Running out of PIDs in the box's PID-space > > (think tens or hundreds of thousands of processes), or (2) Swap- > > storming the box to death. To put it bluntly trying to reserve free > > PID slots is attacking the wrong end of the problem and your so > > called "lockout prevention" could very easily ensure that 10 PIDs > > are available even if the user has swapstormed the box with the > > PIDs he does have. > > I think you are reading this wrong. It's not about reserving PIDs, > it's about exceeding the max-threads limit. This limit is global and > affects every user including root, which is good, as this allows the > sysadmin to fence the system into a controllable state. So once the > system reaches the fence, sysadmin-intervention allows root to exceed > the fence. > > Again, this is much nicer with real resource-controllers, but again > it's also more overhead.
Just an _if()_ ?
may be enable it as an option in kernel config ?
> > Thanks! > > -- > Al > > - > 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/
-- Gustavo Chaín Dumit Alumno de Ingeniería de Ejecución Informática Pontificia Universidad Católica de Valparaiso http://aleph.homeunix.com/~gchain - 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/
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