Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >> Philippe Gerum wrote: >>> Jan Kiszka wrote: >>>> Gilles Chanteperdrix wrote: >>>>> Jan Kiszka wrote: >>>>>> Gilles Chanteperdrix wrote: >>>>>>> Jan Kiszka wrote: >>>>>>>> Hi Gilles, >>>>>>>> >>>>>>>> how much XENO_OPT_SYS_STACKPOOLSZ do I need to run switchtest for >>>>>>>> default settings? At least on x86-64, the default 32K is not enough. >>>>>>>> Unless we talk about GB ;), maybe it makes sense to adjust the default >>>>>>>> size accordingly. >>>>>>> It depends on the arguments you pass to switchtest. >>>>>> None, ie. the default settings. >>>>> Then 6 kernel-space tasks are created. Since switchtest is not the >>>> 6*4 is 20k... Ah, the well-known allocator overhead, I guess. Will try >>>> with >= 40k. >>>> >>> Actually, it is not really an overhead, but rather the fact that it wants at >>> least two initially free pages per heap. >> That would make 22K. The problem is that the management overhead is >> rounded up to another full page, requiring a 8K allocation per 4K >> request. Reminds me of TLSF - if I only had the time... :) > > When allocating 4K, only 4K are allocated. > > I think the problem could rather be that you are running switchtest on a > multi-cpu system, in which same the number of cpu tasks created is 6 by cpu.
That was in fact the problem here. OK, so we should just consider adjusting the pool default for 8K-stack archs (PowerPC64, Blackfin, and maybe also x86-64). Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux _______________________________________________ Xenomai-core mailing list [email protected] https://mail.gna.org/listinfo/xenomai-core
