On Mon, Jul 12, 2010 at 06:52:28PM +0900, Minchan Kim wrote: > Hello. > > On Mon, Jul 12, 2010 at 5:32 PM, Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote: > > Russell, > > > > Hi, > > > > Kukjin Kim wrote: > >> Russell wrote: > >> > So, memory starts at 0x20000000 and finishes at 0x25000000. That's > > fine. > >> > That doesn't mean the section size is 16MB. > >> > > >> > As I've already said, the section size has _nothing_ what so ever to do > >> > with the size of memory, or the granularity of the size of memory. By > >> > way of illustration, it is perfectly legal to have a section size of > >> > 256MB but only have 1MB in a section and this is perfectly legal. So > >> > sections do not have to be completely filled. > >> > > >> Actually, as you know, the hole's area of mem_map is freed from bootmem if > > a > >> section has a hole when initializing sparse memory. > >> > >> I identified that a section doesn't need to be a contiguous area of > > physical > >> memory when reading your comment with the fact that the mem_map of a > > section > >> can be smaller than the size of a section. > >> > >> I found, however, the kernel panics when modifying min_free_kbytes file in > >> the proc filesystem if a section has a hole. > >> > >> While processing the change of min_free_kbytes in the kernel, page > >> descriptors in a hole of an online section is accessed. > > > > As I said, following error happens. > > It would be helpful to me if any opinions or comments. > > > > Could you test below patch? > Also, you should select ARCH_HAS_HOLES_MEMORYMODEL in your config. But hang on. Where are the hole(s)? The DRAM setup is: 0x20000000-0x25000000, 0x40000000-0x50000000, 0x50000000-0x58000000 which with SECTION_SIZE_BITS set to 28 gives three sections of memory, and each sparsemem section does not have a hole. No zone should cross a sparsemem section boundary. Moreover, our pfn_valid() now returns false for any and all invalid PFNs. -- 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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