| Message ID | 20220409073846.22286-5-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | A few cleanup and fixup patches for migration | expand |
Hi Miaohe,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on hnaz-mm/master]
[also build test ERROR on linus/master v5.18-rc1 next-20220408]
[cannot apply to linux/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028
base: https://github.com/hnaz/linux-mm master
config: powerpc64-randconfig-r015-20220408 (https://download.01.org/0day-ci/archive/20220409/202204091914.psVO4TrI-lkp@intel.com/config)
compiler: powerpc64-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/73a982570cc62313c55cc5cbc2dd7acf40601474
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028
git checkout 73a982570cc62313c55cc5cbc2dd7acf40601474
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/mm/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
arch/powerpc/mm/hugetlbpage.c: In function 'follow_huge_pd':
>> arch/powerpc/mm/hugetlbpage.c:537:25: error: too few arguments to function '__migration_entry_wait'
537 | __migration_entry_wait(mm, ptep, ptl);
| ^~~~~~~~~~~~~~~~~~~~~~
In file included from arch/powerpc/mm/hugetlbpage.c:20:
include/linux/swapops.h:233:13: note: declared here
233 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
| ^~~~~~~~~~~~~~~~~~~~~~
vim +/__migration_entry_wait +537 arch/powerpc/mm/hugetlbpage.c
^1da177e4c3f41 arch/ppc64/mm/hugetlbpage.c Linus Torvalds 2005-04-16 507
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 508 struct page *follow_huge_pd(struct vm_area_struct *vma,
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 509 unsigned long address, hugepd_t hpd,
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 510 int flags, int pdshift)
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 511 {
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 512 pte_t *ptep;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 513 spinlock_t *ptl;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 514 struct page *page = NULL;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 515 unsigned long mask;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 516 int shift = hugepd_shift(hpd);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 517 struct mm_struct *mm = vma->vm_mm;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 518
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 519 retry:
ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 520 /*
ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 521 * hugepage directory entries are protected by mm->page_table_lock
ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 522 * Use this instead of huge_pte_lockptr
ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 523 */
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 524 ptl = &mm->page_table_lock;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 525 spin_lock(ptl);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 526
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 527 ptep = hugepte_offset(hpd, address, pdshift);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 528 if (pte_present(*ptep)) {
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 529 mask = (1UL << shift) - 1;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 530 page = pte_page(*ptep);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 531 page += ((address & mask) >> PAGE_SHIFT);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 532 if (flags & FOLL_GET)
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 533 get_page(page);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 534 } else {
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 535 if (is_hugetlb_entry_migration(*ptep)) {
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 536 spin_unlock(ptl);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 @537 __migration_entry_wait(mm, ptep, ptl);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 538 goto retry;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 539 }
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 540 }
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 541 spin_unlock(ptl);
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 542 return page;
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 543 }
50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 544
On 2022/4/9 19:38, kernel test robot wrote: > Hi Miaohe, > > Thank you for the patch! Yet something to improve: > > [auto build test ERROR on hnaz-mm/master] > [also build test ERROR on linus/master v5.18-rc1 next-20220408] > [cannot apply to linux/master] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch] > > url: https://github.com/intel-lab-lkp/linux/commits/Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028 > base: https://github.com/hnaz/linux-mm master > config: powerpc64-randconfig-r015-20220408 (https://download.01.org/0day-ci/archive/20220409/202204091914.psVO4TrI-lkp@intel.com/config) > compiler: powerpc64-linux-gcc (GCC) 11.2.0 > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/73a982570cc62313c55cc5cbc2dd7acf40601474 > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Miaohe-Lin/A-few-cleanup-and-fixup-patches-for-migration/20220409-154028 > git checkout 73a982570cc62313c55cc5cbc2dd7acf40601474 > # save the config file to linux build tree > mkdir build_dir > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/mm/ > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> Oh, powerpc variant is left undone. Will fix it. Thanks! > > All errors (new ones prefixed by >>): > > arch/powerpc/mm/hugetlbpage.c: In function 'follow_huge_pd': >>> arch/powerpc/mm/hugetlbpage.c:537:25: error: too few arguments to function '__migration_entry_wait' > 537 | __migration_entry_wait(mm, ptep, ptl); > | ^~~~~~~~~~~~~~~~~~~~~~ > In file included from arch/powerpc/mm/hugetlbpage.c:20: > include/linux/swapops.h:233:13: note: declared here > 233 | extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > | ^~~~~~~~~~~~~~~~~~~~~~ > > > vim +/__migration_entry_wait +537 arch/powerpc/mm/hugetlbpage.c > > ^1da177e4c3f41 arch/ppc64/mm/hugetlbpage.c Linus Torvalds 2005-04-16 507 > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 508 struct page *follow_huge_pd(struct vm_area_struct *vma, > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 509 unsigned long address, hugepd_t hpd, > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 510 int flags, int pdshift) > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 511 { > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 512 pte_t *ptep; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 513 spinlock_t *ptl; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 514 struct page *page = NULL; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 515 unsigned long mask; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 516 int shift = hugepd_shift(hpd); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 517 struct mm_struct *mm = vma->vm_mm; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 518 > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 519 retry: > ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 520 /* > ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 521 * hugepage directory entries are protected by mm->page_table_lock > ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 522 * Use this instead of huge_pte_lockptr > ed515b6898c367 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2018-06-01 523 */ > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 524 ptl = &mm->page_table_lock; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 525 spin_lock(ptl); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 526 > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 527 ptep = hugepte_offset(hpd, address, pdshift); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 528 if (pte_present(*ptep)) { > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 529 mask = (1UL << shift) - 1; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 530 page = pte_page(*ptep); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 531 page += ((address & mask) >> PAGE_SHIFT); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 532 if (flags & FOLL_GET) > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 533 get_page(page); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 534 } else { > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 535 if (is_hugetlb_entry_migration(*ptep)) { > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 536 spin_unlock(ptl); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 @537 __migration_entry_wait(mm, ptep, ptl); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 538 goto retry; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 539 } > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 540 } > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 541 spin_unlock(ptl); > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 542 return page; > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 543 } > 50791e6de0b5f2 arch/powerpc/mm/hugetlbpage.c Aneesh Kumar K.V 2017-07-06 544 >
On 09.04.22 09:38, Miaohe Lin wrote: > __migration_entry_wait and migration_entry_wait_on_locked assume pte is > always mapped from caller. But this is not the case when it's called from > migration_entry_wait_huge and follow_huge_pmd. And a parameter unmap to > indicate whether pte needs to be unmapped to fix this issue. Hm. migration_entry_wait_on_locked documents "@ptep: mapped pte pointer. Will return with the ptep unmapped. Only required for pte entries, pass NULL for pmd entries." Setting ptep implies that we have a *mapped pte* pointer that requires unmap. If some code sets that although that's not guaranteed, that calling code is wrong and needs to be fixed to not pass a ptep. hugetlbfs never requires a map/unmap. I really don't see we there is need to adjust migration_entry_wait_on_locked(): just don't pass a ptep as documented. What's really nasty here is that hugetlbfs actually mostly works on PMD/PUD, but we call it PTEs. One corner case might be CONT PTEs, but they are also accessed without a map+unmap. Regarding __migration_entry_wait(), I think we should just stop using it for hugetlbfs and have a proper hugetlbfs variant that calls hugetlb_migration_entry_wait(ptep == NULL), and knows that although we're handling ptes, we're usually not actually holding ptes in our hands that need a map+unmap. Something like (including some cleanups mm parameter): diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 32d517a28969..898c407ad8f7 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -234,8 +234,8 @@ extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, spinlock_t *ptl); extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address); -extern void migration_entry_wait_huge(struct vm_area_struct *vma, - struct mm_struct *mm, pte_t *pte); +extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl); +extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte); #else static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) { @@ -261,8 +261,9 @@ static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, spinlock_t *ptl) { } static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address) { } +static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { } static inline void migration_entry_wait_huge(struct vm_area_struct *vma, - struct mm_struct *mm, pte_t *pte) { } + pte_t *pte) { } static inline int is_writable_migration_entry(swp_entry_t entry) { return 0; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 48740e6c3476..2b38eaaa2e60 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5622,7 +5622,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, */ entry = huge_ptep_get(ptep); if (unlikely(is_hugetlb_entry_migration(entry))) { - migration_entry_wait_huge(vma, mm, ptep); + migration_entry_wait_huge(vma, ptep); return 0; } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) return VM_FAULT_HWPOISON_LARGE | @@ -6770,7 +6770,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, } else { if (is_hugetlb_entry_migration(pte)) { spin_unlock(ptl); - __migration_entry_wait(mm, (pte_t *)pmd, ptl); + __migration_entry_wait_huge((pte_t *)pmd, ptl); goto retry; } /* diff --git a/mm/migrate.c b/mm/migrate.c index 231907e89b93..84b685a235fe 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -315,11 +315,26 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, __migration_entry_wait(mm, ptep, ptl); } +void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) +{ + swp_entry_t entry; + pte_t pte; + + spin_lock(ptl); + pte = huge_ptep_get(ptep); + + if (unlikely(!is_hugetlb_entry_migration(pte))) + spin_unlock(ptl); + else + migration_entry_wait_on_locked(pte_to_swp_entry(pte), NULL, ptl); +} + void migration_entry_wait_huge(struct vm_area_struct *vma, struct mm_struct *mm, pte_t *pte) { - spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); - __migration_entry_wait(mm, pte, ptl); + spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->mm, pte); + + __migration_entry_wait_huge(pte, ptl); } #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
On 2022/4/11 19:41, David Hildenbrand wrote: > On 09.04.22 09:38, Miaohe Lin wrote: >> __migration_entry_wait and migration_entry_wait_on_locked assume pte is >> always mapped from caller. But this is not the case when it's called from >> migration_entry_wait_huge and follow_huge_pmd. And a parameter unmap to >> indicate whether pte needs to be unmapped to fix this issue. > > Hm. > > > migration_entry_wait_on_locked documents > > "@ptep: mapped pte pointer. Will return with the ptep unmapped. Only > required for pte entries, pass NULL for pmd entries." > > Setting ptep implies that we have a *mapped pte* pointer that requires unmap. > If some code sets that although that's not guaranteed, that calling code > is wrong and needs to be fixed to not pass a ptep. > > > hugetlbfs never requires a map/unmap. I really don't see we there is need to > adjust migration_entry_wait_on_locked(): just don't pass a ptep as documented. > > What's really nasty here is that hugetlbfs actually mostly works on PMD/PUD, > but we call it PTEs. One corner case might be CONT PTEs, but they are also > accessed without a map+unmap. > > Regarding __migration_entry_wait(), I think we should just stop using it for > hugetlbfs and have a proper hugetlbfs variant that calls > hugetlb_migration_entry_wait(ptep == NULL), and knows that although we're > handling ptes, we're usually not actually holding ptes in our hands > that need a map+unmap. > > > Something like (including some cleanups mm parameter): This really helps! Many thanks! Will try to do this in next version. :) > > > diff --git a/include/linux/swapops.h b/include/linux/swapops.h > index 32d517a28969..898c407ad8f7 100644 > --- a/include/linux/swapops.h > +++ b/include/linux/swapops.h > @@ -234,8 +234,8 @@ extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > spinlock_t *ptl); > extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, > unsigned long address); > -extern void migration_entry_wait_huge(struct vm_area_struct *vma, > - struct mm_struct *mm, pte_t *pte); > +extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl); > +extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte); > #else > static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) > { > @@ -261,8 +261,9 @@ static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, > spinlock_t *ptl) { } > static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, > unsigned long address) { } > +static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { } > static inline void migration_entry_wait_huge(struct vm_area_struct *vma, > - struct mm_struct *mm, pte_t *pte) { } > + pte_t *pte) { } > static inline int is_writable_migration_entry(swp_entry_t entry) > { > return 0; > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 48740e6c3476..2b38eaaa2e60 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -5622,7 +5622,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, > */ > entry = huge_ptep_get(ptep); > if (unlikely(is_hugetlb_entry_migration(entry))) { > - migration_entry_wait_huge(vma, mm, ptep); > + migration_entry_wait_huge(vma, ptep); > return 0; > } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) > return VM_FAULT_HWPOISON_LARGE | > @@ -6770,7 +6770,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, > } else { > if (is_hugetlb_entry_migration(pte)) { > spin_unlock(ptl); > - __migration_entry_wait(mm, (pte_t *)pmd, ptl); > + __migration_entry_wait_huge((pte_t *)pmd, ptl); > goto retry; > } > /* > diff --git a/mm/migrate.c b/mm/migrate.c > index 231907e89b93..84b685a235fe 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -315,11 +315,26 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, > __migration_entry_wait(mm, ptep, ptl); > } > > +void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) > +{ > + swp_entry_t entry; > + pte_t pte; > + > + spin_lock(ptl); > + pte = huge_ptep_get(ptep); > + > + if (unlikely(!is_hugetlb_entry_migration(pte))) > + spin_unlock(ptl); > + else > + migration_entry_wait_on_locked(pte_to_swp_entry(pte), NULL, ptl); > +} > + > void migration_entry_wait_huge(struct vm_area_struct *vma, > struct mm_struct *mm, pte_t *pte) > { > - spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); > - __migration_entry_wait(mm, pte, ptl); > + spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->mm, pte); > + > + __migration_entry_wait_huge(pte, ptl); > } > > #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION >
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 2707bfd43a0d..2c4de1972f99 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -41,7 +41,7 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping, extern int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page, int extra_count); void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, - spinlock_t *ptl); + spinlock_t *ptl, bool unmap); void folio_migrate_flags(struct folio *newfolio, struct folio *folio); void folio_migrate_copy(struct folio *newfolio, struct folio *folio); int folio_migrate_mapping(struct address_space *mapping, diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 32d517a28969..3e6a293f88e0 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -231,7 +231,7 @@ static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) } extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, - spinlock_t *ptl); + spinlock_t *ptl, bool unmap); extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address); extern void migration_entry_wait_huge(struct vm_area_struct *vma, @@ -258,7 +258,7 @@ static inline int is_migration_entry(swp_entry_t swp) } static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, - spinlock_t *ptl) { } + spinlock_t *ptl, bool unmap) { } static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address) { } static inline void migration_entry_wait_huge(struct vm_area_struct *vma, diff --git a/mm/filemap.c b/mm/filemap.c index 3a5ffb5587cd..02f2d920c8cf 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1392,6 +1392,7 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, * @ptep: mapped pte pointer. Will return with the ptep unmapped. Only required * for pte entries, pass NULL for pmd entries. * @ptl: already locked ptl. This function will drop the lock. + * @unmap: indicating whether ptep need to be unmapped. * * Wait for a migration entry referencing the given page to be removed. This is * equivalent to put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE) except @@ -1405,7 +1406,7 @@ static inline int folio_wait_bit_common(struct folio *folio, int bit_nr, * there. */ void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, - spinlock_t *ptl) + spinlock_t *ptl, bool unmap) { struct wait_page_queue wait_page; wait_queue_entry_t *wait = &wait_page.wait; @@ -1442,10 +1443,9 @@ void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep, * a valid reference to the page, and it must take the ptl to remove the * migration entry. So the page is valid until the ptl is dropped. */ - if (ptep) - pte_unmap_unlock(ptep, ptl); - else - spin_unlock(ptl); + spin_unlock(ptl); + if (unmap && ptep) + pte_unmap(ptep); for (;;) { unsigned int flags; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index fb5a549169ce..3fc61a437c2a 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6778,7 +6778,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, } else { if (is_hugetlb_entry_migration(pte)) { spin_unlock(ptl); - __migration_entry_wait(mm, (pte_t *)pmd, ptl); + __migration_entry_wait(mm, (pte_t *)pmd, ptl, false); goto retry; } /* diff --git a/mm/migrate.c b/mm/migrate.c index 044656a14ae2..0bdf27fbc45b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -287,7 +287,7 @@ void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked) * When we return from this function the fault will be retried. */ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, - spinlock_t *ptl) + spinlock_t *ptl, bool unmap) { pte_t pte; swp_entry_t entry; @@ -301,10 +301,12 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, if (!is_migration_entry(entry)) goto out; - migration_entry_wait_on_locked(entry, ptep, ptl); + migration_entry_wait_on_locked(entry, ptep, ptl, unmap); return; out: - pte_unmap_unlock(ptep, ptl); + spin_unlock(ptl); + if (unmap) + pte_unmap(ptep); } void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, @@ -312,14 +314,14 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, { spinlock_t *ptl = pte_lockptr(mm, pmd); pte_t *ptep = pte_offset_map(pmd, address); - __migration_entry_wait(mm, ptep, ptl); + __migration_entry_wait(mm, ptep, ptl, true); } void migration_entry_wait_huge(struct vm_area_struct *vma, struct mm_struct *mm, pte_t *pte) { spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); - __migration_entry_wait(mm, pte, ptl); + __migration_entry_wait(mm, pte, ptl, false); } #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION @@ -330,7 +332,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) ptl = pmd_lock(mm, pmd); if (!is_pmd_migration_entry(*pmd)) goto unlock; - migration_entry_wait_on_locked(pmd_to_swp_entry(*pmd), NULL, ptl); + migration_entry_wait_on_locked(pmd_to_swp_entry(*pmd), NULL, ptl, false); return; unlock: spin_unlock(ptl);
__migration_entry_wait and migration_entry_wait_on_locked assume pte is always mapped from caller. But this is not the case when it's called from migration_entry_wait_huge and follow_huge_pmd. And a parameter unmap to indicate whether pte needs to be unmapped to fix this issue. Fixes: 30dad30922cc ("mm: migration: add migrate_entry_wait_huge()") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- include/linux/migrate.h | 2 +- include/linux/swapops.h | 4 ++-- mm/filemap.c | 10 +++++----- mm/hugetlb.c | 2 +- mm/migrate.c | 14 ++++++++------ 5 files changed, 17 insertions(+), 15 deletions(-)