| Message ID | 20231130101242.2590384-5-42.hyeyoo@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/zsmalloc: Split zsdesc from struct page | expand |
On Thu, Nov 30, 2023 at 07:12:25PM +0900, Hyeonggon Yoo wrote: > +static __maybe_unused int is_first_zsdesc(struct zsdesc *zsdesc) > +{ > + return PagePrivate(zsdesc_page(zsdesc)); > +} static inline bool is_first_zsdesc(struct zsdesc *zsdesc) { return folio_test_private(zsdesc_folio(zsdesc)); } > -static inline struct page *get_first_page(struct zspage *zspage) > +static __maybe_unused inline struct page *get_first_page(struct zspage *zspage) I don't think you need __maybe_unused with inline. > +static __maybe_unused struct zsdesc *get_first_zsdesc(struct zspage *zspage) > +{ > + struct zsdesc *first_zsdesc = zspage->first_zsdesc; > + > + VM_BUG_ON_PAGE(!is_first_zsdesc(first_zsdesc), zsdesc_page(first_zsdesc)); Do we want a VM_BUG_ON_ZSDESC?
On Mon, Dec 4, 2023 at 12:45 PM Matthew Wilcox <willy@infradead.org> wrote: > > On Thu, Nov 30, 2023 at 07:12:25PM +0900, Hyeonggon Yoo wrote: > > +static __maybe_unused int is_first_zsdesc(struct zsdesc *zsdesc) > > +{ > > + return PagePrivate(zsdesc_page(zsdesc)); > > +} > > static inline bool is_first_zsdesc(struct zsdesc *zsdesc) > { > return folio_test_private(zsdesc_folio(zsdesc)); > } PagePrivate(zsdesc_page(zsdesc)) is fine as zsmalloc always allocates a base page, and then build a chain of base pages. That's not going to change anytime soon. But will drop __maybe_unused and add inline. > > -static inline struct page *get_first_page(struct zspage *zspage) > > +static __maybe_unused inline struct page *get_first_page(struct zspage *zspage) > > I don't think you need __maybe_unused with inline. Right, will adjust in v4. > > +static __maybe_unused struct zsdesc *get_first_zsdesc(struct zspage *zspage) > > +{ > > + struct zsdesc *first_zsdesc = zspage->first_zsdesc; > > + > > + VM_BUG_ON_PAGE(!is_first_zsdesc(first_zsdesc), zsdesc_page(first_zsdesc)); > > Do we want a VM_BUG_ON_ZSDESC? If the kernel starts allocating zsdesc separately, we'll need that. But at now, I don't think we need to implement that yet? Thanks! -- Hyeonggon
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 4c9f9a2cb681..c511539bee8c 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -502,6 +502,11 @@ static __maybe_unused int is_first_page(struct page *page) return PagePrivate(page); } +static __maybe_unused int is_first_zsdesc(struct zsdesc *zsdesc) +{ + return PagePrivate(zsdesc_page(zsdesc)); +} + /* Protected by pool->lock */ static inline int get_zspage_inuse(struct zspage *zspage) { @@ -514,7 +519,7 @@ static inline void mod_zspage_inuse(struct zspage *zspage, int val) zspage->inuse += val; } -static inline struct page *get_first_page(struct zspage *zspage) +static __maybe_unused inline struct page *get_first_page(struct zspage *zspage) { struct page *first_page = zsdesc_page(zspage->first_zsdesc); @@ -522,6 +527,14 @@ static inline struct page *get_first_page(struct zspage *zspage) return first_page; } +static __maybe_unused struct zsdesc *get_first_zsdesc(struct zspage *zspage) +{ + struct zsdesc *first_zsdesc = zspage->first_zsdesc; + + VM_BUG_ON_PAGE(!is_first_zsdesc(first_zsdesc), zsdesc_page(first_zsdesc)); + return first_zsdesc; +} + static inline unsigned int get_first_obj_offset(struct page *page) { return page->page_type; @@ -810,7 +823,7 @@ static struct zspage *get_zspage(struct page *page) return zspage; } -static struct page *get_next_page(struct page *page) +static __maybe_unused struct page *get_next_page(struct page *page) { struct zspage *zspage = get_zspage(page); @@ -820,6 +833,16 @@ static struct page *get_next_page(struct page *page) return (struct page *)page->index; } +static __maybe_unused struct zsdesc *get_next_zsdesc(struct zsdesc *zsdesc) +{ + struct zspage *zspage = get_zspage(zsdesc_page(zsdesc)); + + if (unlikely(ZsHugePage(zspage))) + return NULL; + + return zsdesc->next; +} + /** * obj_to_location - get (<page>, <obj_idx>) from encoded object value * @obj: the encoded object value
get_first_page(), get_next_page(), is_first_page() are frequently used throughout zsmalloc code. As replacing them all at once would be hard to review, add alternative helpers and gradually replace its users to use new functions. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> --- mm/zsmalloc.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)