Messages in this thread | | | Subject | Re: PATCH(?): linux-2.4.4-pre2: fork should run child first | Date | Thu, 12 Apr 2001 08:38:35 -0400 | From | Horst von Brand <> |
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"Adam J. Richter" <adam@yggdrasil.com> said:
[...]
> I suppose that running the child first also has a minor > advantage for clone() in that it should make programs that spawn lots > of threads to do little bits of work behave better on machines with a > small number of processors, since the threads that do so little work that > they accomplish they finish within their time slice will not pile up > before they have a chance to run. So, rather than give the parent's CPU > priority to the child only if CLONE_VFORK is not set, I have decided to > do a bit of machete surgery and have the child always inherit all of the > parent's CPU priority all of the time. It simplifies the code and > probably saves a few clock cycles (and before you say that this will > cost a context switch, consider that the child will almost always run > at least one time slice anyhow).
And opens the system up to DoS attacks: You can't have a process fork(2) at will and so increase its (aggregate) CPU priority. -- Dr. Horst H. von Brand mailto:vonbrand@inf.utfsm.cl Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513 - 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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