Messages in this thread | | | Date | Thu, 28 Oct 2004 10:17:31 +0100 (WEST) | Subject | Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4 | From | "Rui Nuno Capela" <> |
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Ingo Molnar wrote: > > * Rui Nuno Capela wrote: > >> The following table compares the state between my RT-U3 and RT-V0.4.3 >> configurations, regarding only the mentioned options: >> >> option RT-U3.0 RT-V0.4.3 >> ---------------------------- ---------- --------- >> CONFIG_DEBUG_SLAB n n >> CONFIG_DEBUG_PREEMPT y y >> CONFIG_DEBUG_SPINLOCK_SLEEP n - >> CONFIG_PREEMPT_TIMING n n >> CONFIG_RWSEM_DEADLOCK_DETECT - y >> CONFIG_FRAME_POINTER y y >> CONFIG_DEBUG_STACKOVERFLOW y y >> CONFIG_DEBUG_STACK_USAGE n n >> CONFIG_DEBUG_PAGEALLOC n n >> >> (dash "-" means that the option is not available in the config). >> >> As you can see, it can only be CONFIG_RWSEM_DEADLOCK_DETECT, being new >> in RT-V0.4.3, that is probably affecting on RT-V0.4.3. I'll try to >> rebuild and test all over without it, and see if it gets any better. > > note that DEBUG_PREEMPT got more expensive in the -V kernels. I'd > suggest to disable all the 'y' ones in both the -U and -V kernel and > compare them then. > > but especially the userspace overhead seems to be significantly higher > in the -V kernel so i'm not quite sure it can all be attributed to > debugging overhead. We'll see. > > also, how does the context-switching rate compare between the two tests? > This test is pretty steady when it's running, so the context-switch > rates can be directly compared, correct? >
OK. That was it. After switching off CONFIG_RWSEM_DEADLOCK_DETECT on RT-V0.4.3, I can say that it's now on par to RT-U3.
Later today, I will conduct some extendeded testing, where I'll able to compare the jackd performance between vanilla, RT-U3 and RT-V0.4.3, on my UP laptop. All kernel configurations will be stripped off from all the debug options.
I will take note of xrun rate, jackd scheduling delay histogram, and cpu usage. Context switch rate will be also acquainted.
Anything else? -- rncbc aka Rui Nuno Capela rncbc@rncbc.org
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