Messages in this thread | | | From | "Bob Picco" <> | Date | Sun, 10 Dec 2006 14:47:30 -0500 | Subject | Re: [RFC] [PATCH] virtual memmap on sparsemem v3 [0/4] introduction |
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Hiroyuki KAMEZAWA wrote: [Fri Dec 08 2006, 01:56:08AM EST] Hi Kame, > Hi, virtual mem_map on sparsemem/generic patch version 3. > > I myself likes this patch. > But someone may feels this patch is intrusive and scattered. > please pointing out. > > Changes v2 -> v3 > - make map/unmap function for general purpose. (for my purpose ;) > - drop memory hotplug support. will be posted after this goes in. > - change pfn_to_page()/page_to_pfn() defintions. > - add CONFIT_SPARSEMEM_VMEMMAP_STATIC config. > - several clean ups. > - drop optimized pfn_valid() patch will be posted later after this goes in. > - add #error to check vmem_map alignment. > > Changes v1 -> v2: > - support memory hotplug case. > - uses static address for vmem_map (ia64) > - added optimized pfn_valid() for ia64 (experimental) > > Intro: > When using SPARSEMEM, pfn_to_page()/page_to_pfn() accesses global big table > of mem_section. if SPARSEMEM_EXTREME, this is 2-level table lookup. Did you gather any performance numbers comparing VIRTUAL_MEM_MAP+SPARSEMEM to SPARSEMEM+EXTREME? I did some quick but inconclusive (small machine) ones when you first posted. There was perhaps a slight degradation in VIRTUAL_MEM_MAP+SPARSEMEM.
bob > > If we can map mem_section->mem_map in (virtually) linear address, we can expect > optimzed pfn <-> page translation. > > Virtual mem_map is not useful for 32bit archs. This uses huge virtual > address range. > > -Kame - 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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