Messages in this thread | | | Date | Mon, 10 Jan 2022 23:49:02 -0800 | Subject | Re: [PATCH v2 27/28] mm: Add isolate_lru_folio() | From | John Hubbard <> |
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On 1/9/22 20:24, Matthew Wilcox (Oracle) wrote: > Turn isolate_lru_page() into a wrapper around isolate_lru_folio(). > TestClearPageLRU() would have always failed on a tail page, so > returning -EBUSY is the same behaviour. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > arch/powerpc/include/asm/mmu_context.h | 1 - > mm/folio-compat.c | 8 +++++ > mm/internal.h | 3 +- > mm/vmscan.c | 43 ++++++++++++-------------- > 4 files changed, 29 insertions(+), 26 deletions(-)
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
thanks, -- John Hubbard NVIDIA
> > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h > index 9ba6b585337f..b9cab0a11421 100644 > --- a/arch/powerpc/include/asm/mmu_context.h > +++ b/arch/powerpc/include/asm/mmu_context.h > @@ -21,7 +21,6 @@ extern void destroy_context(struct mm_struct *mm); > #ifdef CONFIG_SPAPR_TCE_IOMMU > struct mm_iommu_table_group_mem_t; > > -extern int isolate_lru_page(struct page *page); /* from internal.h */ > extern bool mm_iommu_preregistered(struct mm_struct *mm); > extern long mm_iommu_new(struct mm_struct *mm, > unsigned long ua, unsigned long entries, > diff --git a/mm/folio-compat.c b/mm/folio-compat.c > index 749555a232a8..782e766cd1ee 100644 > --- a/mm/folio-compat.c > +++ b/mm/folio-compat.c > @@ -7,6 +7,7 @@ > #include <linux/migrate.h> > #include <linux/pagemap.h> > #include <linux/swap.h> > +#include "internal.h" > > struct address_space *page_mapping(struct page *page) > { > @@ -151,3 +152,10 @@ int try_to_release_page(struct page *page, gfp_t gfp) > return filemap_release_folio(page_folio(page), gfp); > } > EXPORT_SYMBOL(try_to_release_page); > + > +int isolate_lru_page(struct page *page) > +{ > + if (WARN_RATELIMIT(PageTail(page), "trying to isolate tail page")) > + return -EBUSY; > + return isolate_lru_folio((struct folio *)page); > +} > diff --git a/mm/internal.h b/mm/internal.h > index 9a72d1ecdab4..8b90db90e7f2 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -157,7 +157,8 @@ extern unsigned long highest_memmap_pfn; > /* > * in mm/vmscan.c: > */ > -extern int isolate_lru_page(struct page *page); > +int isolate_lru_page(struct page *page); > +int isolate_lru_folio(struct folio *folio); > extern void putback_lru_page(struct page *page); > extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason); > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index fb9584641ac7..ac2f5b76cdb2 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2168,45 +2168,40 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, > } > > /** > - * isolate_lru_page - tries to isolate a page from its LRU list > - * @page: page to isolate from its LRU list > + * isolate_lru_folio - Try to isolate a folio from its LRU list. > + * @folio: Folio to isolate from its LRU list. > * > - * Isolates a @page from an LRU list, clears PageLRU and adjusts the > - * vmstat statistic corresponding to whatever LRU list the page was on. > + * Isolate a @folio from an LRU list and adjust the vmstat statistic > + * corresponding to whatever LRU list the folio was on. > * > - * Returns 0 if the page was removed from an LRU list. > - * Returns -EBUSY if the page was not on an LRU list. > - * > - * The returned page will have PageLRU() cleared. If it was found on > - * the active list, it will have PageActive set. If it was found on > - * the unevictable list, it will have the PageUnevictable bit set. That flag > + * The folio will have its LRU flag cleared. If it was found on the > + * active list, it will have the Active flag set. If it was found on the > + * unevictable list, it will have the Unevictable flag set. These flags > * may need to be cleared by the caller before letting the page go. > * > - * The vmstat statistic corresponding to the list on which the page was > - * found will be decremented. > - * > - * Restrictions: > + * Context: > * > * (1) Must be called with an elevated refcount on the page. This is a > - * fundamental difference from isolate_lru_pages (which is called > + * fundamental difference from isolate_lru_pages() (which is called > * without a stable reference). > - * (2) the lru_lock must not be held. > - * (3) interrupts must be enabled. > + * (2) The lru_lock must not be held. > + * (3) Interrupts must be enabled. > + * > + * Return: 0 if the folio was removed from an LRU list. > + * -EBUSY if the folio was not on an LRU list. > */ > -int isolate_lru_page(struct page *page) > +int isolate_lru_folio(struct folio *folio) > { > - struct folio *folio = page_folio(page); > int ret = -EBUSY; > > - VM_BUG_ON_PAGE(!page_count(page), page); > - WARN_RATELIMIT(PageTail(page), "trying to isolate tail page"); > + VM_BUG_ON_FOLIO(!folio_ref_count(folio), folio); > > - if (TestClearPageLRU(page)) { > + if (folio_test_clear_lru(folio)) { > struct lruvec *lruvec; > > - get_page(page); > + folio_get(folio); > lruvec = folio_lruvec_lock_irq(folio); > - del_page_from_lru_list(page, lruvec); > + lruvec_del_folio(lruvec, folio); > unlock_page_lruvec_irq(lruvec); > ret = 0; > }
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