| Message ID | 20191018101248.33727-13-steven.price@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Generic page walk and ptdump | expand |
Steven Price <steven.price@arm.com> 於 2019年10月19日 週六 下午4:12寫道： > > Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range > for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as > a hole, because it lacks a vma. > > This means each arch has re-implemented page table walking when needed, > for example in the per-arch ptdump walker. > > Remove the requirement to have a vma except when trying to split huge > pages. > > Signed-off-by: Steven Price <steven.price@arm.com> > --- > mm/pagewalk.c | 25 +++++++++++++++++-------- > 1 file changed, 17 insertions(+), 8 deletions(-) > > diff --git a/mm/pagewalk.c b/mm/pagewalk.c > index fc4d98a3a5a0..4139e9163aee 100644 > --- a/mm/pagewalk.c > +++ b/mm/pagewalk.c > @@ -38,7 +38,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, > do { > again: > next = pmd_addr_end(addr, end); > - if (pmd_none(*pmd) || !walk->vma) { > + if (pmd_none(*pmd)) { > if (ops->pte_hole) > err = ops->pte_hole(addr, next, walk); > if (err) > @@ -61,9 +61,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, > if (!ops->pte_entry) > continue; > > - split_huge_pmd(walk->vma, pmd, addr); > - if (pmd_trans_unstable(pmd)) > - goto again; > + if (walk->vma) { > + split_huge_pmd(walk->vma, pmd, addr); > + if (pmd_trans_unstable(pmd)) > + goto again; > + } else if (pmd_leaf(*pmd)) { > + continue; > + } > + > err = walk_pte_range(pmd, addr, next, walk); > if (err) > break; > @@ -84,7 +89,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, > do { > again: > next = pud_addr_end(addr, end); > - if (pud_none(*pud) || !walk->vma) { > + if (pud_none(*pud)) { > if (ops->pte_hole) > err = ops->pte_hole(addr, next, walk); > if (err) > @@ -98,9 +103,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, > break; > } > > - split_huge_pud(walk->vma, pud, addr); > - if (pud_none(*pud)) > - goto again; > + if (walk->vma) { > + split_huge_pud(walk->vma, pud, addr); > + if (pud_none(*pud)) > + goto again; > + } else if (pud_leaf(*pud)) { > + continue; > + } > > if (ops->pmd_entry || ops->pte_entry) > err = walk_pmd_range(pud, addr, next, walk); > -- > 2.20.1 > It's good to me. Tested-by: Zong Li <zong.li@sifive.com>
diff --git a/mm/pagewalk.c b/mm/pagewalk.c index fc4d98a3a5a0..4139e9163aee 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -38,7 +38,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, do { again: next = pmd_addr_end(addr, end); - if (pmd_none(*pmd) || !walk->vma) { + if (pmd_none(*pmd)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -61,9 +61,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, if (!ops->pte_entry) continue; - split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; + if (walk->vma) { + split_huge_pmd(walk->vma, pmd, addr); + if (pmd_trans_unstable(pmd)) + goto again; + } else if (pmd_leaf(*pmd)) { + continue; + } + err = walk_pte_range(pmd, addr, next, walk); if (err) break; @@ -84,7 +89,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, do { again: next = pud_addr_end(addr, end); - if (pud_none(*pud) || !walk->vma) { + if (pud_none(*pud)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -98,9 +103,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, break; } - split_huge_pud(walk->vma, pud, addr); - if (pud_none(*pud)) - goto again; + if (walk->vma) { + split_huge_pud(walk->vma, pud, addr); + if (pud_none(*pud)) + goto again; + } else if (pud_leaf(*pud)) { + continue; + } if (ops->pmd_entry || ops->pte_entry) err = walk_pmd_range(pud, addr, next, walk);
Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as a hole, because it lacks a vma. This means each arch has re-implemented page table walking when needed, for example in the per-arch ptdump walker. Remove the requirement to have a vma except when trying to split huge pages. Signed-off-by: Steven Price <steven.price@arm.com> --- mm/pagewalk.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-)