Restore Cced. On Fri, Jan 21, 2011 at 2:24 AM, KyongHo Cho <pullip.linux@xxxxxxxxx> wrote: > On Thu, Jan 20, 2011 at 11:28 PM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote: >> On Thu, Jan 20, 2011 at 06:45:39PM +0900, KyongHo Cho wrote: >>> Sparsemem allows that a bank of memory spans over several adjacent >>> sections if the start address and the end address of the bank >>> belong to different sections. >>> When gathering statictics of physical memory in mem_init() and >>> show_mem(), this possiblity was not considered. >> >> Please write down the result if we doesn't consider this patch. >> I can understand what happens but for making good description and review, >> merging easily, it would be better to write down the result without >> the patch explicitly. >> > As we know that each section has its own memmap and > a contiguous chunk of physical memory that is represented by 'bank' in meminfo > can be larger than the size of a section. > "page++" in the current implementation can access invalid memory area. > The size of the section is 256 MiB in ARM and the number of banks in > meminfo is 8. > This means that the maximum size of the physical memory cannot be grow than 2GiB > to avoid this problem in the current implementation. > Thus we need to fix the calculation of the last page descriptor in > terms of sections. > > This patch determines the last page descriptor in a memmap with > min(last_pfn_of_bank, last_pfn_of_current_section) > If there remains physical memory not consumed, it calculates the last > page descriptor > with min(last_pfn_of_bank, last_pfn_of_next_section). > >> >> Hmm.. new ifndef magic makes code readability bad. >> Couldn't we do it by simple pfn iterator not page and pfn_valid check? >> > True. > We need to consider the implementation again. > I think the previous implementation gave the importance to the > efficiency but to the readability. > Please consider readability and consistency with other architectures if we can do. :) Thanks. -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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