On Fri, Feb 11, 2022 at 11:41:30AM -0500, Zi Yan wrote: > From: Zi Yan <[email protected]> > > has_unmovable_pages() is only used in mm/page_isolation.c. Move it from > mm/page_alloc.c and make it static. > > Signed-off-by: Zi Yan <[email protected]> > Reviewed-by: Oscar Salvador <[email protected]>
Reviewed-by: Mike Rapoport <[email protected]> > --- > include/linux/page-isolation.h | 2 - > mm/page_alloc.c | 119 --------------------------------- > mm/page_isolation.c | 119 +++++++++++++++++++++++++++++++++ > 3 files changed, 119 insertions(+), 121 deletions(-) > > diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h > index 572458016331..e14eddf6741a 100644 > --- a/include/linux/page-isolation.h > +++ b/include/linux/page-isolation.h > @@ -33,8 +33,6 @@ static inline bool is_migrate_isolate(int migratetype) > #define MEMORY_OFFLINE 0x1 > #define REPORT_FAILURE 0x2 > > -struct page *has_unmovable_pages(struct zone *zone, struct page *page, > - int migratetype, int flags); > void set_pageblock_migratetype(struct page *page, int migratetype); > int move_freepages_block(struct zone *zone, struct page *page, > int migratetype, int *num_movable); > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cface1d38093..e2c6a67fc386 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8962,125 +8962,6 @@ void *__init alloc_large_system_hash(const char > *tablename, > return table; > } > > -/* > - * This function checks whether pageblock includes unmovable pages or not. > - * > - * PageLRU check without isolation or lru_lock could race so that > - * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable > - * check without lock_page also may miss some movable non-lru pages at > - * race condition. So you can't expect this function should be exact. > - * > - * Returns a page without holding a reference. If the caller wants to > - * dereference that page (e.g., dumping), it has to make sure that it > - * cannot get removed (e.g., via memory unplug) concurrently. > - * > - */ > -struct page *has_unmovable_pages(struct zone *zone, struct page *page, > - int migratetype, int flags) > -{ > - unsigned long iter = 0; > - unsigned long pfn = page_to_pfn(page); > - unsigned long offset = pfn % pageblock_nr_pages; > - > - if (is_migrate_cma_page(page)) { > - /* > - * CMA allocations (alloc_contig_range) really need to mark > - * isolate CMA pageblocks even when they are not movable in fact > - * so consider them movable here. > - */ > - if (is_migrate_cma(migratetype)) > - return NULL; > - > - return page; > - } > - > - for (; iter < pageblock_nr_pages - offset; iter++) { > - page = pfn_to_page(pfn + iter); > - > - /* > - * Both, bootmem allocations and memory holes are marked > - * PG_reserved and are unmovable. We can even have unmovable > - * allocations inside ZONE_MOVABLE, for example when > - * specifying "movablecore". > - */ > - if (PageReserved(page)) > - return page; > - > - /* > - * If the zone is movable and we have ruled out all reserved > - * pages then it should be reasonably safe to assume the rest > - * is movable. > - */ > - if (zone_idx(zone) == ZONE_MOVABLE) > - continue; > - > - /* > - * Hugepages are not in LRU lists, but they're movable. > - * THPs are on the LRU, but need to be counted as #small pages. > - * We need not scan over tail pages because we don't > - * handle each tail page individually in migration. > - */ > - if (PageHuge(page) || PageTransCompound(page)) { > - struct page *head = compound_head(page); > - unsigned int skip_pages; > - > - if (PageHuge(page)) { > - if > (!hugepage_migration_supported(page_hstate(head))) > - return page; > - } else if (!PageLRU(head) && !__PageMovable(head)) { > - return page; > - } > - > - skip_pages = compound_nr(head) - (page - head); > - iter += skip_pages - 1; > - continue; > - } > - > - /* > - * We can't use page_count without pin a page > - * because another CPU can free compound page. > - * This check already skips compound tails of THP > - * because their page->_refcount is zero at all time. > - */ > - if (!page_ref_count(page)) { > - if (PageBuddy(page)) > - iter += (1 << buddy_order(page)) - 1; > - continue; > - } > - > - /* > - * The HWPoisoned page may be not in buddy system, and > - * page_count() is not 0. > - */ > - if ((flags & MEMORY_OFFLINE) && PageHWPoison(page)) > - continue; > - > - /* > - * We treat all PageOffline() pages as movable when offlining > - * to give drivers a chance to decrement their reference count > - * in MEM_GOING_OFFLINE in order to indicate that these pages > - * can be offlined as there are no direct references anymore. > - * For actually unmovable PageOffline() where the driver does > - * not support this, we will fail later when trying to actually > - * move these pages that still have a reference count > 0. > - * (false negatives in this function only) > - */ > - if ((flags & MEMORY_OFFLINE) && PageOffline(page)) > - continue; > - > - if (__PageMovable(page) || PageLRU(page)) > - continue; > - > - /* > - * If there are RECLAIMABLE pages, we need to check > - * it. But now, memory offline itself doesn't call > - * shrink_node_slabs() and it still to be fixed. > - */ > - return page; > - } > - return NULL; > -} > - > #ifdef CONFIG_CONTIG_ALLOC > static unsigned long pfn_max_align_down(unsigned long pfn) > { > diff --git a/mm/page_isolation.c b/mm/page_isolation.c > index f67c4c70f17f..b34f1310aeaa 100644 > --- a/mm/page_isolation.c > +++ b/mm/page_isolation.c > @@ -15,6 +15,125 @@ > #define CREATE_TRACE_POINTS > #include <trace/events/page_isolation.h> > > +/* > + * This function checks whether pageblock includes unmovable pages or not. > + * > + * PageLRU check without isolation or lru_lock could race so that > + * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable > + * check without lock_page also may miss some movable non-lru pages at > + * race condition. So you can't expect this function should be exact. > + * > + * Returns a page without holding a reference. If the caller wants to > + * dereference that page (e.g., dumping), it has to make sure that it > + * cannot get removed (e.g., via memory unplug) concurrently. > + * > + */ > +static struct page *has_unmovable_pages(struct zone *zone, struct page *page, > + int migratetype, int flags) > +{ > + unsigned long iter = 0; > + unsigned long pfn = page_to_pfn(page); > + unsigned long offset = pfn % pageblock_nr_pages; > + > + if (is_migrate_cma_page(page)) { > + /* > + * CMA allocations (alloc_contig_range) really need to mark > + * isolate CMA pageblocks even when they are not movable in fact > + * so consider them movable here. > + */ > + if (is_migrate_cma(migratetype)) > + return NULL; > + > + return page; > + } > + > + for (; iter < pageblock_nr_pages - offset; iter++) { > + page = pfn_to_page(pfn + iter); > + > + /* > + * Both, bootmem allocations and memory holes are marked > + * PG_reserved and are unmovable. We can even have unmovable > + * allocations inside ZONE_MOVABLE, for example when > + * specifying "movablecore". > + */ > + if (PageReserved(page)) > + return page; > + > + /* > + * If the zone is movable and we have ruled out all reserved > + * pages then it should be reasonably safe to assume the rest > + * is movable. > + */ > + if (zone_idx(zone) == ZONE_MOVABLE) > + continue; > + > + /* > + * Hugepages are not in LRU lists, but they're movable. > + * THPs are on the LRU, but need to be counted as #small pages. > + * We need not scan over tail pages because we don't > + * handle each tail page individually in migration. > + */ > + if (PageHuge(page) || PageTransCompound(page)) { > + struct page *head = compound_head(page); > + unsigned int skip_pages; > + > + if (PageHuge(page)) { > + if > (!hugepage_migration_supported(page_hstate(head))) > + return page; > + } else if (!PageLRU(head) && !__PageMovable(head)) { > + return page; > + } > + > + skip_pages = compound_nr(head) - (page - head); > + iter += skip_pages - 1; > + continue; > + } > + > + /* > + * We can't use page_count without pin a page > + * because another CPU can free compound page. > + * This check already skips compound tails of THP > + * because their page->_refcount is zero at all time. > + */ > + if (!page_ref_count(page)) { > + if (PageBuddy(page)) > + iter += (1 << buddy_order(page)) - 1; > + continue; > + } > + > + /* > + * The HWPoisoned page may be not in buddy system, and > + * page_count() is not 0. > + */ > + if ((flags & MEMORY_OFFLINE) && PageHWPoison(page)) > + continue; > + > + /* > + * We treat all PageOffline() pages as movable when offlining > + * to give drivers a chance to decrement their reference count > + * in MEM_GOING_OFFLINE in order to indicate that these pages > + * can be offlined as there are no direct references anymore. > + * For actually unmovable PageOffline() where the driver does > + * not support this, we will fail later when trying to actually > + * move these pages that still have a reference count > 0. > + * (false negatives in this function only) > + */ > + if ((flags & MEMORY_OFFLINE) && PageOffline(page)) > + continue; > + > + if (__PageMovable(page) || PageLRU(page)) > + continue; > + > + /* > + * If there are RECLAIMABLE pages, we need to check > + * it. But now, memory offline itself doesn't call > + * shrink_node_slabs() and it still to be fixed. > + */ > + return page; > + } > + return NULL; > +} > + > static int set_migratetype_isolate(struct page *page, int migratetype, int > isol_flags) > { > struct zone *zone = page_zone(page); > -- > 2.34.1 > -- Sincerely yours, Mike. _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
