On Sat, Sep 19, 2020 at 03:47:31PM +0800, Huang Pei wrote: > MIPS page fault path take 3 exceptions (1 TLB Miss + 2 TLB Invalid), but > the second TLB Invalid exception is just triggered by __update_tlb from > do_page_fault writing tlb without _PAGE_VALID set. With this patch, it > only take 1 TLB Miss + 1 TLB Invalid exceptions > > This version removes pte_sw_mkyoung without polluting MM code and makes > page fault delay of MIPS on par with other architecture and covers both > no-RIXI and RIXI MIPS CPUS > > [1]: https://lkml.kernel.org/lkml/1591416169-26666-1-git-send-email > -maobibo@xxxxxxxxxxx/ > --- > V3: > - reformat with whitespace cleaned up following Thomas's advice > V2: > - remove unused asm-generic definition of pte_sw_mkyoung following Mao's > advice > --- > Co-developed-by: Huang Pei <huangpei@xxxxxxxxxxx> > Signed-off-by: Huang Pei <huangpei@xxxxxxxxxxx> > Co-developed-by: Bibo Mao <maobibo@xxxxxxxxxx> > --- > arch/mips/include/asm/pgtable.h | 10 ++++------ > arch/mips/mm/cache.c | 25 +++++++++++++------------ > include/linux/pgtable.h | 8 -------- > mm/memory.c | 3 --- > 4 files changed, 17 insertions(+), 29 deletions(-) > > diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h > index dd7a0f552cac..931fb35730f0 100644 > --- a/arch/mips/include/asm/pgtable.h > +++ b/arch/mips/include/asm/pgtable.h > @@ -27,11 +27,11 @@ struct vm_area_struct; > > #define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \ > _page_cachable_default) > -#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \ > - _page_cachable_default) > +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \ > + __READABLE | _page_cachable_default) you are still doing a white space changes here. > #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \ > - _page_cachable_default) > -#define PAGE_READONLY __pgprot(_PAGE_PRESENT | \ > + __READABLE | _page_cachable_default) > +#define PAGE_READONLY __pgprot(_PAGE_PRESENT | __READABLE | \ I've grepped for usage of PAGE_SHARED and PAGE_READONLY and found arch/mips/kvm/mmu.c and arch/mips/kernel/vdso.c. I wonder 1. Is this usage correct or should we use protection_map[X] ? 2. Are this still correct after the change in this patch ? Right now I'm in favour to fist clean up asm/pgtable.h to get rid of all unneeded PAGE_XXX defines and make mm/cache.c rixi part more readable before applying this patch. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]
