| Message ID | 20230131062853.28449-1-Kuan-Ying.Lee@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/doc: Replace isolate_lru_page with folio_isolate_lru | expand |
Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> writes: > Since we introduce folio, replace isolate_lru_page() with > folio_isolate_lru(). > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> > --- > Documentation/mm/page_migration.rst | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) This seems like a good patch to copy to linux-mm - done now. The patch perhaps is a closer match to what's in linux-next, but it seems that, if we're going to update this document, we should reflect the use folios throughout? Thanks, jon > diff --git a/Documentation/mm/page_migration.rst b/Documentation/mm/page_migration.rst > index 11493bad7112..1f8cc175d770 100644 > --- a/Documentation/mm/page_migration.rst > +++ b/Documentation/mm/page_migration.rst > @@ -69,8 +69,8 @@ In kernel use of migrate_pages() > > Lists of pages to be migrated are generated by scanning over > pages and moving them into lists. This is done by > - calling isolate_lru_page(). > - Calling isolate_lru_page() increases the references to the page > + calling folio_isolate_lru(). > + Calling folio_isolate_lru() increases the references to the page > so that it cannot vanish while the page migration occurs. > It also prevents the swapper or other scans from encountering > the page. > @@ -89,7 +89,7 @@ How migrate_pages() works > > migrate_pages() does several passes over its list of pages. A page is moved > if all references to a page are removable at the time. The page has > -already been removed from the LRU via isolate_lru_page() and the refcount > +already been removed from the LRU via folio_isolate_lru() and the refcount > is increased so that the page cannot be freed while page migration occurs. > > Steps: > -- > 2.18.0
On Thu, Feb 02, 2023 at 11:02:11AM -0700, Jonathan Corbet wrote: > Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> writes: > > > Since we introduce folio, replace isolate_lru_page() with > > folio_isolate_lru(). > > > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> > > --- > > Documentation/mm/page_migration.rst | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > This seems like a good patch to copy to linux-mm - done now. > > The patch perhaps is a closer match to what's in linux-next, but it > seems that, if we're going to update this document, we should reflect > the use folios throughout? Most of the current users of migrate_pages() still use isolate_lru_page() so I think that updating page_migration.rst to folios is premature. But when we do the update it also should include the translations. > Thanks, > > jon > > > diff --git a/Documentation/mm/page_migration.rst b/Documentation/mm/page_migration.rst > > index 11493bad7112..1f8cc175d770 100644 > > --- a/Documentation/mm/page_migration.rst > > +++ b/Documentation/mm/page_migration.rst > > @@ -69,8 +69,8 @@ In kernel use of migrate_pages() > > > > Lists of pages to be migrated are generated by scanning over > > pages and moving them into lists. This is done by > > - calling isolate_lru_page(). > > - Calling isolate_lru_page() increases the references to the page > > + calling folio_isolate_lru(). > > + Calling folio_isolate_lru() increases the references to the page > > so that it cannot vanish while the page migration occurs. > > It also prevents the swapper or other scans from encountering > > the page. > > @@ -89,7 +89,7 @@ How migrate_pages() works > > > > migrate_pages() does several passes over its list of pages. A page is moved > > if all references to a page are removable at the time. The page has > > -already been removed from the LRU via isolate_lru_page() and the refcount > > +already been removed from the LRU via folio_isolate_lru() and the refcount > > is increased so that the page cannot be freed while page migration occurs. > > > > Steps: > > -- > > 2.18.0 >
On Thu, Feb 09, 2023 at 03:10:07PM +0200, Mike Rapoport wrote: > On Thu, Feb 02, 2023 at 11:02:11AM -0700, Jonathan Corbet wrote: > > Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> writes: > > > > > Since we introduce folio, replace isolate_lru_page() with > > > folio_isolate_lru(). > > > > > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> > > > --- > > > Documentation/mm/page_migration.rst | 6 +++--- > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > This seems like a good patch to copy to linux-mm - done now. > > > > The patch perhaps is a closer match to what's in linux-next, but it > > seems that, if we're going to update this document, we should reflect > > the use folios throughout? > > Most of the current users of migrate_pages() still use isolate_lru_page() > so I think that updating page_migration.rst to folios is premature. > But when we do the update it also should include the translations. It's a slim majority -- 9 of isolate_lru_pages() and 7 of folio_isolate_lru(). I don't think that changing the documentation is premature; we should document the functions we want people to use. I'd be surprised if isolate_lru_pages() still existed in six months.
On Thu, Feb 09, 2023 at 01:58:09PM +0000, Matthew Wilcox wrote: > On Thu, Feb 09, 2023 at 03:10:07PM +0200, Mike Rapoport wrote: > > On Thu, Feb 02, 2023 at 11:02:11AM -0700, Jonathan Corbet wrote: > > > Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> writes: > > > > > > > Since we introduce folio, replace isolate_lru_page() with > > > > folio_isolate_lru(). > > > > > > > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> > > > > --- > > > > Documentation/mm/page_migration.rst | 6 +++--- > > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > > > This seems like a good patch to copy to linux-mm - done now. > > > > > > The patch perhaps is a closer match to what's in linux-next, but it > > > seems that, if we're going to update this document, we should reflect > > > the use folios throughout? > > > > Most of the current users of migrate_pages() still use isolate_lru_page() > > so I think that updating page_migration.rst to folios is premature. > > But when we do the update it also should include the translations. > > It's a slim majority -- 9 of isolate_lru_pages() and 7 of > folio_isolate_lru(). I don't think that changing the documentation is > premature; we should document the functions we want people to use. > I'd be surprised if isolate_lru_pages() still existed in six months. That's a bit of a problem when documentation describes how things are done rather than how to do them, but I don't have a strong feeling about updating the docs while we are still in the transition period or postponing it until e.g. isolate_lru_page() is gone. But in any case, this should be much more comprehensive update rather than replacing two occurrences out of three in a single file.
diff --git a/Documentation/mm/page_migration.rst b/Documentation/mm/page_migration.rst index 11493bad7112..1f8cc175d770 100644 --- a/Documentation/mm/page_migration.rst +++ b/Documentation/mm/page_migration.rst @@ -69,8 +69,8 @@ In kernel use of migrate_pages() Lists of pages to be migrated are generated by scanning over pages and moving them into lists. This is done by - calling isolate_lru_page(). - Calling isolate_lru_page() increases the references to the page + calling folio_isolate_lru(). + Calling folio_isolate_lru() increases the references to the page so that it cannot vanish while the page migration occurs. It also prevents the swapper or other scans from encountering the page. @@ -89,7 +89,7 @@ How migrate_pages() works migrate_pages() does several passes over its list of pages. A page is moved if all references to a page are removable at the time. The page has -already been removed from the LRU via isolate_lru_page() and the refcount +already been removed from the LRU via folio_isolate_lru() and the refcount is increased so that the page cannot be freed while page migration occurs. Steps:
Since we introduce folio, replace isolate_lru_page() with folio_isolate_lru(). Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> --- Documentation/mm/page_migration.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)