Messages in this thread |  | | Date | Thu, 26 Aug 2010 23:25:39 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [RFC PATCH 00/11] sched: CFS low-latency features |
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On Thu, 26 Aug 2010, Peter Zijlstra wrote: > > Fudging fork seems dubious at best, it seems generated by the use of > timer_create(.evp->sigev_notify = SIGEV_THREAD), which is a really > broken thing to do, it has very ill defined semantics and is utterly > unable to properly cope with error cases. Furthermore its trivial to > actually correctly implement the desired behaviour, so I'm really > skeptical on this front; friends don't let friends use SIGEV_THREAD.
SIGEV_THREAD is the best proof that the whole posix timer interface was comitte[e]d under the influence of not to be revealed mind-altering substances.
I completely object to add timer specific wakeup magic and support for braindead fork orgies to the kernel proper. All that mess can be fixed in user space by using sensible functionality.
Providing support for misdesigned crap just for POSIX compliance reasons and to make some of the blind abusers of that very same crap happy would be a completely stupid decision.
In fact that would make a brilliant precedence case for forcing the kernel to solve user space madness at the expense of kernel complexity. If we follow down that road we get requests for extra functionality for AIO, networking and whatever in a split second with no real good reason to reject them anymore.
Thanks,
tglx
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