| Message ID | 20200919074731.22372-1-huangpei@loongson.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V3] MIPS: make userspace mapping young by default | expand |
On Sat, Sep 19, 2020 at 03:47:31PM +0800, Huang Pei wrote: Ping? > 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@loongson.cn/ > --- > 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@loongson.cn> > Signed-off-by: Huang Pei <huangpei@loongson.cn> > Co-developed-by: Bibo Mao <maobibo@loonson.cn> > --- > 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) > #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 | \ > _page_cachable_default) > #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \ > _PAGE_GLOBAL | _page_cachable_default) > @@ -414,8 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte) > return pte; > } > > -#define pte_sw_mkyoung pte_mkyoung > - > #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT > static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; } > > diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c > index 3e81ba000096..ed75f2871aad 100644 > --- a/arch/mips/mm/cache.c > +++ b/arch/mips/mm/cache.c > @@ -159,22 +159,23 @@ static inline void setup_protection_map(void) > { > if (cpu_has_rixi) { > protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > + protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > - protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > + protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > > protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); > - protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); > + protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ); > - protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE); > - protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT); > - protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); > - protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); > + protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | __READABLE); > + protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); > + protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); > + > > } else { > protection_map[0] = PAGE_NONE; > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index e8cbc2e795d5..ef9c5fa8673e 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -377,14 +377,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres > * To be differentiate with macro pte_mkyoung, this macro is used on platforms > * where software maintains page access bit. > */ > -#ifndef pte_sw_mkyoung > -static inline pte_t pte_sw_mkyoung(pte_t pte) > -{ > - return pte; > -} > -#define pte_sw_mkyoung pte_sw_mkyoung > -#endif > - > #ifndef pte_savedwrite > #define pte_savedwrite pte_write > #endif > diff --git a/mm/memory.c b/mm/memory.c > index 602f4283122f..5100ab5bcf77 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2705,7 +2705,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) > } > flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); > entry = mk_pte(new_page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > entry = maybe_mkwrite(pte_mkdirty(entry), vma); > /* > * Clear the pte entry and flush it first, before updating the > @@ -3386,7 +3385,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) > __SetPageUptodate(page); > > entry = mk_pte(page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > if (vma->vm_flags & VM_WRITE) > entry = pte_mkwrite(pte_mkdirty(entry)); > > @@ -3661,7 +3659,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct page *page) > > flush_icache_page(vma, page); > entry = mk_pte(page, vma->vm_page_prot); > - entry = pte_sw_mkyoung(entry); > if (write) > entry = maybe_mkwrite(pte_mkdirty(entry), vma); > /* copy-on-write page */ > -- > 2.17.1 >
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@loongson.cn/ > --- > 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@loongson.cn> > Signed-off-by: Huang Pei <huangpei@loongson.cn> > Co-developed-by: Bibo Mao <maobibo@loonson.cn> > --- > 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.
On Fri, Oct 02, 2020 at 02:35:03PM +0200, Thomas Bogendoerfer wrote: Hi, > 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@loongson.cn/ > > --- > > 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@loongson.cn> > > Signed-off-by: Huang Pei <huangpei@loongson.cn> > > Co-developed-by: Bibo Mao <maobibo@loonson.cn> > > --- > > 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 | \ > sorry, my bad > 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 > for arch/mips/kvm/mmu.c, the comment says: ... /* Also set valid and dirty, so refill handler doesn't have to */ *ptep = pte_mkyoung(pte_mkdirty(pfn_pte(pfn, PAGE_SHARED))); ... the net effect is the same, dirty and valid, so I think it is ok; for arch/mips/kernel/vdso.c, both mappings are kernel mapping, which means the physical memory(or io memory) is already allocated and will not be reclaimed by kernel. > 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. > I think we can clean up rixi part of mm/cache.c after this patch, or within V4; > Thomas. > > -- > Crap can work. Given enough thrust pigs will fly, but it's not necessarily a > good idea. [ RFC1925, 2.3 ]
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) #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 | \ _page_cachable_default) #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \ _PAGE_GLOBAL | _page_cachable_default) @@ -414,8 +414,6 @@ static inline pte_t pte_mkyoung(pte_t pte) return pte; } -#define pte_sw_mkyoung pte_mkyoung - #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; } diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c index 3e81ba000096..ed75f2871aad 100644 --- a/arch/mips/mm/cache.c +++ b/arch/mips/mm/cache.c @@ -159,22 +159,23 @@ static inline void setup_protection_map(void) { if (cpu_has_rixi) { protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); - protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); + protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); - protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); - protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT); - protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT); - protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT); - protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT); + protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); + protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); + protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); + protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); + protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ); - protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC); + protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ); - protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE); - protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT); - protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT); - protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); - protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE); + protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | __READABLE); + protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); + protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT | __READABLE); + protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); + protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | __READABLE); + } else { protection_map[0] = PAGE_NONE; diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index e8cbc2e795d5..ef9c5fa8673e 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -377,14 +377,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres * To be differentiate with macro pte_mkyoung, this macro is used on platforms * where software maintains page access bit. */ -#ifndef pte_sw_mkyoung -static inline pte_t pte_sw_mkyoung(pte_t pte) -{ - return pte; -} -#define pte_sw_mkyoung pte_sw_mkyoung -#endif - #ifndef pte_savedwrite #define pte_savedwrite pte_write #endif diff --git a/mm/memory.c b/mm/memory.c index 602f4283122f..5100ab5bcf77 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2705,7 +2705,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) } flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = mk_pte(new_page, vma->vm_page_prot); - entry = pte_sw_mkyoung(entry); entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* * Clear the pte entry and flush it first, before updating the @@ -3386,7 +3385,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf) __SetPageUptodate(page); entry = mk_pte(page, vma->vm_page_prot); - entry = pte_sw_mkyoung(entry); if (vma->vm_flags & VM_WRITE) entry = pte_mkwrite(pte_mkdirty(entry)); @@ -3661,7 +3659,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct page *page) flush_icache_page(vma, page); entry = mk_pte(page, vma->vm_page_prot); - entry = pte_sw_mkyoung(entry); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* copy-on-write page */
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@loongson.cn/ --- 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@loongson.cn> Signed-off-by: Huang Pei <huangpei@loongson.cn> Co-developed-by: Bibo Mao <maobibo@loonson.cn> --- 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(-)