On Mon, 25 May 2020 10:52:37 +0800 Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
> It is not necessary to flush tlb page on all CPUs if suitable PTE
> entry exists already during page fault handling, just updating
> TLB is fine.
>
> Here redefine flush_tlb_fix_spurious_fault as empty on MIPS system.
>
> ...
>
> --- a/arch/mips/include/asm/pgtable.h
> +++ b/arch/mips/include/asm/pgtable.h
> @@ -478,6 +478,8 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
> return __pgprot(prot);
> }
>
> +#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
> +
static inline C would be preferred, if that works. For a number of reasons:
- looks nicer
- more likely to get a code comment (for some reason)
- adds typechecking. So right now a MIPS developer could do
struct wibble a;
struct wobble b;
flush_tlb_fix_spurious_fault(&a, &b);
and there would be no compiler warning. Then the code gets merged
upstream and in come the embarrassing emails!
- avoids unused-var warnings
foo()
{
struct address_space a;
struct vm_area_struct v;
flush_tlb_fix_spurious_fault(&v, &a);
}
will generate unused-variable warnings if
flush_tlb_fix_spurious_fault() is a macro. Making
flush_tlb_fix_spurious_fault() inlined C prevents this.
