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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 30E6A40008 X-Stat-Signature: odfo8daiqeb8ukiwa6ds4o1w9rgpbwrt X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1745917394-769085 X-HE-Meta: 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 Mwp4j5mx 8xxNW4xw5Z/VTnxtW7VNdfubk/cThR3eqbuzjm5TjyPmigQRWIORb1El17BHueHPsi/tLBjObbOHl40Ji/JGjIW6yfAIrHskKX+WoKO7q0ALOCLUQxBZMGCTU0t4iMaWJz93sApW0Ody2EJSIVxBqzPEMDrbkQLC4jCJM7AEkq80kGRo= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 29/04/25 12:36 pm, Lance Yang wrote: > Hey Dev, > > Hmm... I also hit the same compilation errors: > > In file included from ./include/linux/kasan.h:37, >                  from ./include/linux/slab.h:260, >                  from ./include/linux/crypto.h:19, >                  from arch/x86/kernel/asm-offsets.c:9: > ./include/linux/pgtable.h: In function ‘modify_prot_start_ptes’: > ./include/linux/pgtable.h:905:15: error: implicit declaration of > function ‘ptep_modify_prot_start’ [-Werror=implicit-function-declaration] >   905 |         pte = ptep_modify_prot_start(vma, addr, ptep); >       |               ^~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h:905:15: error: incompatible types when > assigning to type ‘pte_t’ from type ‘int’ > ./include/linux/pgtable.h:909:27: error: incompatible types when > assigning to type ‘pte_t’ from type ‘int’ >   909 |                 tmp_pte = ptep_modify_prot_start(vma, addr, ptep); >       |                           ^~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h: In function ‘modify_prot_commit_ptes’: > ./include/linux/pgtable.h:925:17: error: implicit declaration of > function ‘ptep_modify_prot_commit’ [-Werror=implicit-function-declaration] >   925 |                 ptep_modify_prot_commit(vma, addr, ptep, > old_pte, pte); >       |                 ^~~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h: At top level: > ./include/linux/pgtable.h:1360:21: error: conflicting types for > ‘ptep_modify_prot_start’; have ‘pte_t(struct vm_area_struct *, long > unsigned int,  pte_t *)’ >  1360 | static inline pte_t ptep_modify_prot_start(struct > vm_area_struct *vma, >       |                     ^~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h:905:15: note: previous implicit declaration of > ‘ptep_modify_prot_start’ with type ‘int()’ >   905 |         pte = ptep_modify_prot_start(vma, addr, ptep); >       |               ^~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h:1371:20: warning: conflicting types for > ‘ptep_modify_prot_commit’; have ‘void(struct vm_area_struct *, long > unsigned int,  pte_t *, pte_t,  pte_t)’ >  1371 | static inline void ptep_modify_prot_commit(struct > vm_area_struct *vma, >       |                    ^~~~~~~~~~~~~~~~~~~~~~~ > ./include/linux/pgtable.h:1371:20: error: static declaration of > ‘ptep_modify_prot_commit’ follows non-static declaration > ./include/linux/pgtable.h:925:17: note: previous implicit declaration of > ‘ptep_modify_prot_commit’ with type ‘void(struct vm_area_struct *, long > unsigned int,  pte_t *, pte_t,  pte_t)’ >   925 |                 ptep_modify_prot_commit(vma, addr, ptep, > old_pte, pte); >       |                 ^~~~~~~~~~~~~~~~~~~~~~~ >   CC /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/objtool/ > libstring.o >   CC /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/objtool/ > libctype.o >   CC /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/objtool/ > str_error_r.o >   CC /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/objtool/ > librbtree.o > cc1: some warnings being treated as errors > make[2]: *** [scripts/Makefile.build:98: arch/x86/kernel/asm-offsets.s] > Error 1 > make[1]: *** [/home/runner/work/mm-test-robot/mm-test-robot/linux/ > Makefile:1280: prepare0] Error 2 > make[1]: *** Waiting for unfinished jobs.... >   LD /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/objtool/ > objtool-in.o >   LINK /home/runner/work/mm-test-robot/mm-test-robot/linux/tools/ > objtool/objtool > make: *** [Makefile:248: __sub-make] Error 2 > > Well, modify_prot_start_ptes() calls ptep_modify_prot_start(), but x86 > does not define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION. To avoid > implicit declaration errors, the architecture-independent > ptep_modify_prot_start() must be defined before modify_prot_start_ptes(). > > With the changes below, things work correctly now ;) Ah thanks! My bad :( > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 10cdb87ccecf..d9d6c49bb914 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -895,44 +895,6 @@ static inline void wrprotect_ptes(struct mm_struct > *mm, unsigned long addr, >  } >  #endif > > -/* See the comment for ptep_modify_prot_start */ > -#ifndef modify_prot_start_ptes > -static inline pte_t modify_prot_start_ptes(struct vm_area_struct *vma, > -        unsigned long addr, pte_t *ptep, unsigned int nr) > -{ > -    pte_t pte, tmp_pte; > - > -    pte = ptep_modify_prot_start(vma, addr, ptep); > -    while (--nr) { > -        ptep++; > -        addr += PAGE_SIZE; > -        tmp_pte = ptep_modify_prot_start(vma, addr, ptep); > -        if (pte_dirty(tmp_pte)) > -            pte = pte_mkdirty(pte); > -        if (pte_young(tmp_pte)) > -            pte = pte_mkyoung(pte); > -    } > -    return pte; > -} > -#endif > - > -/* See the comment for ptep_modify_prot_commit */ > -#ifndef modify_prot_commit_ptes > -static inline void modify_prot_commit_ptes(struct vm_area_struct *vma, > unsigned long addr, > -        pte_t *ptep, pte_t old_pte, pte_t pte, unsigned int nr) > -{ > -    for (;;) { > -        ptep_modify_prot_commit(vma, addr, ptep, old_pte, pte); > -        if (--nr == 0) > -            break; > -        ptep++; > -        addr += PAGE_SIZE; > -        old_pte = pte_next_pfn(old_pte); > -        pte = pte_next_pfn(pte); > -    } > -} > -#endif > - >  /* >   * On some architectures hardware does not set page access bit when > accessing >   * memory page, it is responsibility of software setting this bit. It > brings > @@ -1375,6 +1337,45 @@ static inline void ptep_modify_prot_commit(struct > vm_area_struct *vma, >      __ptep_modify_prot_commit(vma, addr, ptep, pte); >  } >  #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */ > + > +/* See the comment for ptep_modify_prot_start */ > +#ifndef modify_prot_start_ptes > +static inline pte_t modify_prot_start_ptes(struct vm_area_struct *vma, > +        unsigned long addr, pte_t *ptep, unsigned int nr) > +{ > +    pte_t pte, tmp_pte; > + > +    pte = ptep_modify_prot_start(vma, addr, ptep); > +    while (--nr) { > +        ptep++; > +        addr += PAGE_SIZE; > +        tmp_pte = ptep_modify_prot_start(vma, addr, ptep); > +        if (pte_dirty(tmp_pte)) > +            pte = pte_mkdirty(pte); > +        if (pte_young(tmp_pte)) > +            pte = pte_mkyoung(pte); > +    } > +    return pte; > +} > +#endif > + > +/* See the comment for ptep_modify_prot_commit */ > +#ifndef modify_prot_commit_ptes > +static inline void modify_prot_commit_ptes(struct vm_area_struct *vma, > unsigned long addr, > +        pte_t *ptep, pte_t old_pte, pte_t pte, unsigned int nr) > +{ > +    for (;;) { > +        ptep_modify_prot_commit(vma, addr, ptep, old_pte, pte); > +        if (--nr == 0) > +            break; > +        ptep++; > +        addr += PAGE_SIZE; > +        old_pte = pte_next_pfn(old_pte); > +        pte = pte_next_pfn(pte); > +    } > +} > +#endif > + >  #endif /* CONFIG_MMU */ > >  /* > -- > > Thanks, > Lance > > On 2025/4/29 13:23, Dev Jain wrote: >> This patchset optimizes the mprotect() system call for large folios >> by PTE-batching. >> >> We use the following test cases to measure performance, mprotect()'ing >> the mapped memory to read-only then read-write 40 times: >> >> Test case 1: Mapping 1G of memory, touching it to get PMD-THPs, then >> pte-mapping those THPs >> Test case 2: Mapping 1G of memory with 64K mTHPs >> Test case 3: Mapping 1G of memory with 4K pages >> >> Average execution time on arm64, Apple M3: >> Before the patchset: >> T1: 7.9 seconds   T2: 7.9 seconds   T3: 4.2 seconds >> >> After the patchset: >> T1: 2.1 seconds   T2: 2.2 seconds   T3: 4.2 seconds >> >> Observing T1/T2 and T3 before the patchset, we also remove the regression >> introduced by ptep_get() on a contpte block. And, for large folios we get >> an almost 74% performance improvement. >> >> v1->v2: >>   - Rebase onto mm-unstable (6ebffe676fcf: util_macros.h: make the >> header more resilient) >>   - Abridge the anon-exclusive condition (Lance Yang) >> >> Dev Jain (7): >>    mm: Refactor code in mprotect >>    mm: Optimize mprotect() by batch-skipping PTEs >>    mm: Add batched versions of ptep_modify_prot_start/commit >>    arm64: Add batched version of ptep_modify_prot_start >>    arm64: Add batched version of ptep_modify_prot_commit >>    mm: Batch around can_change_pte_writable() >>    mm: Optimize mprotect() through PTE-batching >> >>   arch/arm64/include/asm/pgtable.h |  10 ++ >>   arch/arm64/mm/mmu.c              |  21 +++- >>   include/linux/mm.h               |   4 +- >>   include/linux/pgtable.h          |  42 ++++++++ >>   mm/gup.c                         |   2 +- >>   mm/huge_memory.c                 |   4 +- >>   mm/memory.c                      |   6 +- >>   mm/mprotect.c                    | 165 ++++++++++++++++++++----------- >>   mm/pgtable-generic.c             |  16 ++- >>   9 files changed, 198 insertions(+), 72 deletions(-) >> >