| Message ID | 20221123051319.1312582-1-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | documentation/mm: Update pmd_present() in arch_pgtable_helpers.rst | expand |
On 23.11.22 06:13, Anshuman Khandual wrote: > Although pmd_present() might seem to indicate a valid and mapped pmd entry, > in reality it returns true when pmd_page() points to a valid page in memory > , regardless whether the pmd entry is mapped or not. Andrea Arcangeli had > earlier explained [1] the required semantics for pmd_present(). This just > updates the documentation for pmd_present() as required. > > [1] https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ > > Cc: Jonathan Corbet <corbet@lwn.net> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Mike Rapoport <rppt@kernel.org> > Cc: linux-mm@kvack.org > Cc: linux-doc@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > This applies on v6.1-rc6 > > The latest trigger was from an earlier discussion here. > > https://lore.kernel.org/all/53c0c955-7afe-905b-468a-cd7ac81238c5@arm.com/ > > Documentation/mm/arch_pgtable_helpers.rst | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Documentation/mm/arch_pgtable_helpers.rst b/Documentation/mm/arch_pgtable_helpers.rst > index cbaee9e59241..fd2a19df884e 100644 > --- a/Documentation/mm/arch_pgtable_helpers.rst > +++ b/Documentation/mm/arch_pgtable_helpers.rst > @@ -94,7 +94,7 @@ PMD Page Table Helpers > +---------------------------+--------------------------------------------------+ > | pmd_trans_huge | Tests a Transparent Huge Page (THP) at PMD | > +---------------------------+--------------------------------------------------+ > -| pmd_present | Tests a valid mapped PMD | > +| pmd_present | Tests whether pmd_page() points to valid memory | > +---------------------------+--------------------------------------------------+ > | pmd_young | Tests a young PMD | > +---------------------------+--------------------------------------------------+ Acked-by: David Hildenbrand <david@redhat.com>
diff --git a/Documentation/mm/arch_pgtable_helpers.rst b/Documentation/mm/arch_pgtable_helpers.rst index cbaee9e59241..fd2a19df884e 100644 --- a/Documentation/mm/arch_pgtable_helpers.rst +++ b/Documentation/mm/arch_pgtable_helpers.rst @@ -94,7 +94,7 @@ PMD Page Table Helpers +---------------------------+--------------------------------------------------+ | pmd_trans_huge | Tests a Transparent Huge Page (THP) at PMD | +---------------------------+--------------------------------------------------+ -| pmd_present | Tests a valid mapped PMD | +| pmd_present | Tests whether pmd_page() points to valid memory | +---------------------------+--------------------------------------------------+ | pmd_young | Tests a young PMD | +---------------------------+--------------------------------------------------+
Although pmd_present() might seem to indicate a valid and mapped pmd entry, in reality it returns true when pmd_page() points to a valid page in memory , regardless whether the pmd entry is mapped or not. Andrea Arcangeli had earlier explained [1] the required semantics for pmd_present(). This just updates the documentation for pmd_present() as required. [1] https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: linux-mm@kvack.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- This applies on v6.1-rc6 The latest trigger was from an earlier discussion here. https://lore.kernel.org/all/53c0c955-7afe-905b-468a-cd7ac81238c5@arm.com/ Documentation/mm/arch_pgtable_helpers.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)