Messages in this thread | | | Date | Thu, 24 Apr 2014 22:24:43 +0200 | From | Peter Zijlstra <> | Subject | Re: Real-time scheduling policies and hyper-threading |
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On Fri, Apr 25, 2014 at 12:16:52AM +0400, Kirill Tkhai wrote: > 24.04.2014, 22:59, "Peter Zijlstra" <peterz@infradead.org>: > > [snip] > > >> Does anyone use rt-scheduler for runtime-like cpu-bound tasks? > > > > So in general cpu bound tasks in the RT classes (FIFO/RR/DEADLINE) are > > bad and can make the system go funny. > > > > For general system health it is important that various system tasks > > (kthreads usually) can run. Many of these kthreads run at !rt prios, and > > by having cpu bound tasks in rt prios they don't get to run. > > One more word to this. I had such expirience on 2.6.33 kernel with RT patch > and weak hardware (sparc32). > > Networking was actively used and application did not use any IO operations. > > User needs to set all RT priorities by himself. It's necessary to set RT > priorities at least for softirqs and rcus. RT bandwidth must be switched > off. > > The most giving optimization, which I receive, was after rejection from NAPI > for network adapters and splitting interrupt handler on hard and threadparts. > In this case game with binding for everything strongly improves the picture > for single problem.
Sure, it can be made to work, but you really need to know what you're doing and you get to keep all pieces when it comes apart :-) -- 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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