Messages in this thread | | | Date | Fri, 29 Aug 2003 12:03:48 +0200 | From | "J.A. Magallon" <> | Subject | Re: x86, ARM, PARISC, PPC, MIPS and Sparc folks please run this |
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On 08.29, Jamie Lokier wrote: > Dear All, [...] > > I already got a surprise (to me): my Athlon MP is much slower > accessing multiple mappings which are within 32k of each other, than > mappings which are further apart, although it is coherent. The L1 > data cache is 64k. (The explanation is easy: virtually indexed, > physically tagged cache moves data among cache lines, possibly via L2). >
Sorry if this is a stupid question, but have you heard about 64K-aliasing ? We have seen it in P3/P4, do not know if Athlons also suffer it. In short, x86 is crap. It slows like a dog when accessing two memory positions sparated by 2^n (address decoder has two 16 bits adders, instead of 1 32 bits..., cache is 16 bit tagged, etc...)
-- J.A. Magallon <jamagallon@able.es> \ Software is like sex: werewolf.able.es \ It's better when it's free Mandrake Linux release 9.2 (Cooker) for i586 Linux 2.4.22-jam1m (gcc 3.3.1 (Mandrake Linux 9.2 3.3.1-1mdk)) - 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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