| Message ID | 20230727183745.682880-1-ppbuk5246@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | damon: Use pmdp_get instead of drect dereferencing pmd. | expand |
Hi Levi, Thank you for this patch. Nit for the subject, what about s/drect/directly/? Also, let's remove the period at the end. On Fri, 28 Jul 2023 03:37:45 +0900 Levi Yun <ppbuk5246@gmail.com> wrote: > As ptep_get, Use the pmdp_get wrapper when we accessing pmdval > instead of direct dereferencing pmd. Nit: s/Use/use/ and s/direct/directly > > Signed-off-by: Levi Yun <ppbuk5246@gmail.com> > --- > mm/damon/ops-common.c | 2 +- > mm/damon/paddr.c | 2 +- > mm/damon/vaddr.c | 22 ++++++++++++++-------- > 3 files changed, 16 insertions(+), 10 deletions(-) > > diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c > index e940802a15a4..ac1c3fa80f98 100644 > --- a/mm/damon/ops-common.c > +++ b/mm/damon/ops-common.c > @@ -54,7 +54,7 @@ void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr > void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr) > { > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > - struct folio *folio = damon_get_folio(pmd_pfn(*pmd)); > + struct folio *folio = damon_get_folio(pmd_pfn(pmdp_get(pmd))); > > if (!folio) > return; > diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c > index 40801e38fcf0..909db25efb35 100644 > --- a/mm/damon/paddr.c > +++ b/mm/damon/paddr.c > @@ -94,7 +94,7 @@ static bool __damon_pa_young(struct folio *folio, struct vm_area_struct *vma, > mmu_notifier_test_young(vma->vm_mm, addr); > } else { > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > - *accessed = pmd_young(*pvmw.pmd) || > + *accessed = pmd_young(pmdp_get(pvmw.pmd)) || > !folio_test_idle(folio) || > mmu_notifier_test_young(vma->vm_mm, addr); > #else > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 2fcc9731528a..82f7865719fe 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -301,16 +301,19 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, > unsigned long next, struct mm_walk *walk) > { > pte_t *pte; > + pmd_t pmde; > spinlock_t *ptl; > > - if (pmd_trans_huge(*pmd)) { > + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { I don't think we really need to use pmdp_get_lockless() here, since we will do this check again with the lock, and we have the fallback for the intermediate changes. > ptl = pmd_lock(walk->mm, pmd); > - if (!pmd_present(*pmd)) { > + pmde = pmdp_get(pmd); > + > + if (!pmd_present(pmde)) { > spin_unlock(ptl); > return 0; > } > > - if (pmd_trans_huge(*pmd)) { > + if (pmd_trans_huge(pmde)) { > damon_pmdp_mkold(pmd, walk->vma, addr); > spin_unlock(ptl); > return 0; > @@ -434,26 +437,29 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, > { > pte_t *pte; > pte_t ptent; > + pmd_t pmde; This would cause below build warning if CONFIG_TRANSPARENT_HUGEPAGE is not defined. .../mm/damon/vaddr.c:440:8: warning: unused variable 'pmde' [-Wunused-variable] 440 | pmd_t pmde; | ^~~~ > spinlock_t *ptl; > struct folio *folio; > struct damon_young_walk_private *priv = walk->private; > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > - if (pmd_trans_huge(*pmd)) { > + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { Again, pmdp_get() might be enough? > ptl = pmd_lock(walk->mm, pmd); > - if (!pmd_present(*pmd)) { > + pmde = pmdp_get(pmd); > + > + if (!pmd_present(pmde)) { > spin_unlock(ptl); > return 0; > } > > - if (!pmd_trans_huge(*pmd)) { > + if (!pmd_trans_huge(pmde)) { > spin_unlock(ptl); > goto regular_page; > } > - folio = damon_get_folio(pmd_pfn(*pmd)); > + folio = damon_get_folio(pmd_pfn(pmde)); > if (!folio) > goto huge_out; > - if (pmd_young(*pmd) || !folio_test_idle(folio) || > + if (pmd_young(pmde) || !folio_test_idle(folio) || > mmu_notifier_test_young(walk->mm, > addr)) > priv->young = true; > -- > 2.37.2 > Thanks, SJ
Hi SJ. Thanks for looking into this. > Nit for the subject, what about s/drect/directly/? Also, let's remove the > period at the end. > > On Fri, 28 Jul 2023 03:37:45 +0900 Levi Yun <ppbuk5246@gmail.com> wrote: Thanks. But I don't know why period is added thou I sent via git send-email .. > > - if (pmd_trans_huge(*pmd)) { > > + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { > > I don't think we really need to use pmdp_get_lockless() here, since we will do > this check again with the lock, and we have the fallback for the intermediate > changes. Agree. I'll change. Thanks :) > > @@ -434,26 +437,29 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, > > { > > pte_t *pte; > > pte_t ptent; > > + pmd_t pmde; > > This would cause below build warning if CONFIG_TRANSPARENT_HUGEPAGE is not > defined. > > .../mm/damon/vaddr.c:440:8: warning: unused variable 'pmde' [-Wunused-variable] > 440 | pmd_t pmde; > | ^~~~ > > > > spinlock_t *ptl; > > struct folio *folio; > > struct damon_young_walk_private *priv = walk->private; > > > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > > - if (pmd_trans_huge(*pmd)) { > > + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { Oh.. I miss this. Many thanks..! > Thanks, > SJ Many Thanks..! --------- Sincerely, Levi.
Hi Levi, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] [also build test WARNING on linus/master v6.5-rc3 next-20230728] [cannot apply to sj/damon/next] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Levi-Yun/damon-Use-pmdp_get-instead-of-drect-dereferencing-pmd/20230728-024044 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20230727183745.682880-1-ppbuk5246%40gmail.com patch subject: [PATCH] damon: Use pmdp_get instead of drect dereferencing pmd. config: i386-randconfig-i016-20230727 (https://download.01.org/0day-ci/archive/20230728/202307281532.pVsrTsL2-lkp@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce: (https://download.01.org/0day-ci/archive/20230728/202307281532.pVsrTsL2-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202307281532.pVsrTsL2-lkp@intel.com/ All warnings (new ones prefixed by >>): mm/damon/vaddr.c: In function 'damon_young_pmd_entry': >> mm/damon/vaddr.c:440:15: warning: unused variable 'pmde' [-Wunused-variable] 440 | pmd_t pmde; | ^~~~ vim +/pmde +440 mm/damon/vaddr.c 434 435 static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, 436 unsigned long next, struct mm_walk *walk) 437 { 438 pte_t *pte; 439 pte_t ptent; > 440 pmd_t pmde; 441 spinlock_t *ptl; 442 struct folio *folio; 443 struct damon_young_walk_private *priv = walk->private; 444
This build warning is fixed in v2:
https://lore.kernel.org/all/20230727212157.2985025-1-ppbuk5246@gmail.com/
On Fri, Jul 28, 2023 at 9:09 AM kernel test robot <lkp@intel.com> wrote:
>
> Hi Levi,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on akpm-mm/mm-everything]
> [also build test WARNING on linus/master v6.5-rc3 next-20230728]
> [cannot apply to sj/damon/next]
> [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#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Levi-Yun/damon-Use-pmdp_get-instead-of-drect-dereferencing-pmd/20230728-024044
> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link: https://lore.kernel.org/r/20230727183745.682880-1-ppbuk5246%40gmail.com
> patch subject: [PATCH] damon: Use pmdp_get instead of drect dereferencing pmd.
> config: i386-randconfig-i016-20230727 (https://download.01.org/0day-ci/archive/20230728/202307281532.pVsrTsL2-lkp@intel.com/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20230728/202307281532.pVsrTsL2-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202307281532.pVsrTsL2-lkp@intel.com/
>
> All warnings (new ones prefixed by >>):
>
> mm/damon/vaddr.c: In function 'damon_young_pmd_entry':
> >> mm/damon/vaddr.c:440:15: warning: unused variable 'pmde' [-Wunused-variable]
> 440 | pmd_t pmde;
> | ^~~~
>
>
> vim +/pmde +440 mm/damon/vaddr.c
>
> 434
> 435 static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
> 436 unsigned long next, struct mm_walk *walk)
> 437 {
> 438 pte_t *pte;
> 439 pte_t ptent;
> > 440 pmd_t pmde;
> 441 spinlock_t *ptl;
> 442 struct folio *folio;
> 443 struct damon_young_walk_private *priv = walk->private;
> 444
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
>
diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c index e940802a15a4..ac1c3fa80f98 100644 --- a/mm/damon/ops-common.c +++ b/mm/damon/ops-common.c @@ -54,7 +54,7 @@ void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr) { #ifdef CONFIG_TRANSPARENT_HUGEPAGE - struct folio *folio = damon_get_folio(pmd_pfn(*pmd)); + struct folio *folio = damon_get_folio(pmd_pfn(pmdp_get(pmd))); if (!folio) return; diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c index 40801e38fcf0..909db25efb35 100644 --- a/mm/damon/paddr.c +++ b/mm/damon/paddr.c @@ -94,7 +94,7 @@ static bool __damon_pa_young(struct folio *folio, struct vm_area_struct *vma, mmu_notifier_test_young(vma->vm_mm, addr); } else { #ifdef CONFIG_TRANSPARENT_HUGEPAGE - *accessed = pmd_young(*pvmw.pmd) || + *accessed = pmd_young(pmdp_get(pvmw.pmd)) || !folio_test_idle(folio) || mmu_notifier_test_young(vma->vm_mm, addr); #else diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 2fcc9731528a..82f7865719fe 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -301,16 +301,19 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long next, struct mm_walk *walk) { pte_t *pte; + pmd_t pmde; spinlock_t *ptl; - if (pmd_trans_huge(*pmd)) { + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { ptl = pmd_lock(walk->mm, pmd); - if (!pmd_present(*pmd)) { + pmde = pmdp_get(pmd); + + if (!pmd_present(pmde)) { spin_unlock(ptl); return 0; } - if (pmd_trans_huge(*pmd)) { + if (pmd_trans_huge(pmde)) { damon_pmdp_mkold(pmd, walk->vma, addr); spin_unlock(ptl); return 0; @@ -434,26 +437,29 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, { pte_t *pte; pte_t ptent; + pmd_t pmde; spinlock_t *ptl; struct folio *folio; struct damon_young_walk_private *priv = walk->private; #ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (pmd_trans_huge(*pmd)) { + if (pmd_trans_huge(pmdp_get_lockless(pmd))) { ptl = pmd_lock(walk->mm, pmd); - if (!pmd_present(*pmd)) { + pmde = pmdp_get(pmd); + + if (!pmd_present(pmde)) { spin_unlock(ptl); return 0; } - if (!pmd_trans_huge(*pmd)) { + if (!pmd_trans_huge(pmde)) { spin_unlock(ptl); goto regular_page; } - folio = damon_get_folio(pmd_pfn(*pmd)); + folio = damon_get_folio(pmd_pfn(pmde)); if (!folio) goto huge_out; - if (pmd_young(*pmd) || !folio_test_idle(folio) || + if (pmd_young(pmde) || !folio_test_idle(folio) || mmu_notifier_test_young(walk->mm, addr)) priv->young = true;
As ptep_get, Use the pmdp_get wrapper when we accessing pmdval instead of direct dereferencing pmd. Signed-off-by: Levi Yun <ppbuk5246@gmail.com> --- mm/damon/ops-common.c | 2 +- mm/damon/paddr.c | 2 +- mm/damon/vaddr.c | 22 ++++++++++++++-------- 3 files changed, 16 insertions(+), 10 deletions(-)