On 02/10/2015 12:42 PM, Toshi Kani wrote: > On Tue, 2015-02-10 at 10:59 -0800, Dave Hansen wrote: >> On 02/09/2015 02:45 PM, Toshi Kani wrote: >>> Implement huge KVA mapping interfaces on x86. Select >>> HAVE_ARCH_HUGE_VMAP when X86_64 or X86_32 with X86_PAE is set. >>> Without X86_PAE set, the X86_32 kernel has the 2-level page >>> tables and cannot provide the huge KVA mappings. >> >> Not that it's a big deal, but what's the limitation with the 2-level >> page tables on 32-bit? We have a 4MB large page size available there >> and we already use it for the kernel linear mapping. > > ioremap() calls arch-neutral ioremap_page_range() to set up I/O mappings > with PTEs. This patch-set enables ioremap_page_range() to set up PUD & > PMD mappings. With 2-level page table, I do not think this PUD/PMD > mapping code works unless we add some special code. What actually breaks, though? Can't you just disable the pud code via ioremap_pud_enabled()? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>