From: Mike Kravetz <mike.krav...@oracle.com> Date: Sun, 18 Dec 2016 16:42:52 -0800
> On 12/17/2016 07:12 PM, David Miller wrote: >> From: Mike Kravetz <mike.krav...@oracle.com> >> Date: Fri, 16 Dec 2016 10:35:28 -0800 >> >>> @@ -166,6 +166,7 @@ bool kern_addr_valid(unsigned long addr); >>> #define _PAGE_EXEC_4V _AC(0x0000000000000080,UL) /* Executable Page >>> */ >>> #define _PAGE_W_4V _AC(0x0000000000000040,UL) /* Writable */ >>> #define _PAGE_SOFT_4V _AC(0x0000000000000030,UL) /* Software bits >>> */ >>> +#define _PAGE_SHR_CTX_4V _AC(0x0000000000000020,UL) /* Shared Context >>> */ >>> #define _PAGE_PRESENT_4V _AC(0x0000000000000010,UL) /* Present >>> */ >>> #define _PAGE_RESV_4V _AC(0x0000000000000008,UL) /* Reserved >>> */ >>> #define _PAGE_SZ16GB_4V _AC(0x0000000000000007,UL) /* 16GB Page >>> */ >> >> You really don't need this. >> >> The VMA is available, and you can obtain the information you need >> about whether this is a shared mapping or not from the. It just isn't >> being passed down into things like set_huge_pte_at(). Simply make it >> do so. >> > > I was more concerned about the page table walk code at tlb/tsb miss time. > Specifically, the code after tsb_miss_page_table_walk_sun4v_fastpath in > tsb.S. AFAICT, the tsb entries should have been created when the pte entries > were created. Yet, this code is still walking the page table and creating > tsb entries. We do not have a pointer to the vma here, and I thought it > would be somewhat difficult to get access. This is the reason why I went > down the path of a page flag. You are right, you will need a page flag for that part.
