I didn't spot any issues with this nice clean up so:
Reviewed-by: Alistair Popple <[email protected]> Dan Williams <[email protected]> writes: > Now that fsdax DMA-idle detection no longer depends on catching > transitions of page->_refcount to 1, and all users of pgmap pages get > access to them via pgmap_request_folios(), remove > put_devmap_managed_page_refs() and associated infrastructure. This > includes the pgmap references taken at the beginning of time for each > page because those @pgmap references are now arbitrated via > pgmap_request_folios(). > > Cc: Matthew Wilcox <[email protected]> > Cc: Jan Kara <[email protected]> > Cc: "Darrick J. Wong" <[email protected]> > Cc: Christoph Hellwig <[email protected]> > Cc: John Hubbard <[email protected]> > Cc: Alistair Popple <[email protected]> > Cc: Jason Gunthorpe <[email protected]> > Signed-off-by: Dan Williams <[email protected]> > --- > include/linux/mm.h | 30 ------------------------------ > mm/gup.c | 6 ++---- > mm/memremap.c | 38 -------------------------------------- > mm/swap.c | 2 -- > 4 files changed, 2 insertions(+), 74 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 8bbcccbc5565..c63dfc804f1e 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1082,30 +1082,6 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf); > * back into memory. > */ > > -#if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_FS_DAX) > -DECLARE_STATIC_KEY_FALSE(devmap_managed_key); > - > -bool __put_devmap_managed_page_refs(struct page *page, int refs); > -static inline bool put_devmap_managed_page_refs(struct page *page, int refs) > -{ > - if (!static_branch_unlikely(&devmap_managed_key)) > - return false; > - if (!is_zone_device_page(page)) > - return false; > - return __put_devmap_managed_page_refs(page, refs); > -} > -#else /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */ > -static inline bool put_devmap_managed_page_refs(struct page *page, int refs) > -{ > - return false; > -} > -#endif /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */ > - > -static inline bool put_devmap_managed_page(struct page *page) > -{ > - return put_devmap_managed_page_refs(page, 1); > -} > - > /* 127: arbitrary random number, small enough to assemble well */ > #define folio_ref_zero_or_close_to_overflow(folio) \ > ((unsigned int) folio_ref_count(folio) + 127u <= 127u) > @@ -1202,12 +1178,6 @@ static inline void put_page(struct page *page) > { > struct folio *folio = page_folio(page); > > - /* > - * For some devmap managed pages we need to catch refcount transition > - * from 2 to 1: > - */ > - if (put_devmap_managed_page(&folio->page)) > - return; > folio_put(folio); > } > > diff --git a/mm/gup.c b/mm/gup.c > index ce00a4c40da8..e49b1f46faa5 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -87,8 +87,7 @@ static inline struct folio *try_get_folio(struct page > *page, int refs) > * belongs to this folio. > */ > if (unlikely(page_folio(page) != folio)) { > - if (!put_devmap_managed_page_refs(&folio->page, refs)) > - folio_put_refs(folio, refs); > + folio_put_refs(folio, refs); > goto retry; > } > > @@ -184,8 +183,7 @@ static void gup_put_folio(struct folio *folio, int refs, > unsigned int flags) > refs *= GUP_PIN_COUNTING_BIAS; > } > > - if (!put_devmap_managed_page_refs(&folio->page, refs)) > - folio_put_refs(folio, refs); > + folio_put_refs(folio, refs); > } > > /** > diff --git a/mm/memremap.c b/mm/memremap.c > index 368ff41c560b..53fe30bb79bb 100644 > --- a/mm/memremap.c > +++ b/mm/memremap.c > @@ -94,19 +94,6 @@ bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned > long pfn) > return false; > } > > -static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id) > -{ > - const struct range *range = &pgmap->ranges[range_id]; > - > - return (range->start + range_len(range)) >> PAGE_SHIFT; > -} > - > -static unsigned long pfn_len(struct dev_pagemap *pgmap, unsigned long > range_id) > -{ > - return (pfn_end(pgmap, range_id) - > - pfn_first(pgmap, range_id)) >> pgmap->vmemmap_shift; > -} > - > static void pageunmap_range(struct dev_pagemap *pgmap, int range_id) > { > struct range *range = &pgmap->ranges[range_id]; > @@ -138,10 +125,6 @@ void memunmap_pages(struct dev_pagemap *pgmap) > int i; > > percpu_ref_kill(&pgmap->ref); > - if (pgmap->type != MEMORY_DEVICE_PRIVATE && > - pgmap->type != MEMORY_DEVICE_COHERENT) > - for (i = 0; i < pgmap->nr_range; i++) > - percpu_ref_put_many(&pgmap->ref, pfn_len(pgmap, i)); > > wait_for_completion(&pgmap->done); > > @@ -267,9 +250,6 @@ static int pagemap_range(struct dev_pagemap *pgmap, > struct mhp_params *params, > memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], > PHYS_PFN(range->start), > PHYS_PFN(range_len(range)), pgmap); > - if (pgmap->type != MEMORY_DEVICE_PRIVATE && > - pgmap->type != MEMORY_DEVICE_COHERENT) > - percpu_ref_get_many(&pgmap->ref, pfn_len(pgmap, range_id)); > return 0; > > err_add_memory: > @@ -584,21 +564,3 @@ void pgmap_release_folios(struct folio *folio, int > nr_folios) > for (iter = folio, i = 0; i < nr_folios; iter = folio_next(folio), i++) > folio_put(iter); > } > - > -#ifdef CONFIG_FS_DAX > -bool __put_devmap_managed_page_refs(struct page *page, int refs) > -{ > - if (page->pgmap->type != MEMORY_DEVICE_FS_DAX) > - return false; > - > - /* > - * fsdax page refcounts are 1-based, rather than 0-based: if > - * refcount is 1, then the page is free and the refcount is > - * stable because nobody holds a reference on the page. > - */ > - if (page_ref_sub_return(page, refs) == 1) > - wake_up_var(page); > - return true; > -} > -EXPORT_SYMBOL(__put_devmap_managed_page_refs); > -#endif /* CONFIG_FS_DAX */ > diff --git a/mm/swap.c b/mm/swap.c > index 955930f41d20..0742b84fbf17 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -1003,8 +1003,6 @@ void release_pages(struct page **pages, int nr) > unlock_page_lruvec_irqrestore(lruvec, flags); > lruvec = NULL; > } > - if (put_devmap_managed_page(&folio->page)) > - continue; > if (folio_put_testzero(folio)) > free_zone_device_page(&folio->page); > continue;
