| Message ID | cb877f73f4fff8d309611082ec740a7065b1ade0.1676424378.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Change the return value for page isolation functions | expand |
On Wed, Feb 15, 2023 at 06:39:37PM +0800, Baolin Wang wrote: > Now the isolate_movable_page() can only return 0 or -EBUSY, and no users > will care about the negative return value, thus we can convert the > isolate_movable_page() to return a boolean value to make the code more > clear when checking the movable page isolation state. > > No functional changes intended. > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> A couple of nits below, not worth respinning the patch series for: > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > index c88b96b48be7..6b252f519c86 100644 > --- a/include/linux/migrate.h > +++ b/include/linux/migrate.h > @@ -71,7 +71,7 @@ extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, > unsigned long private, enum migrate_mode mode, int reason, > unsigned int *ret_succeeded); > extern struct page *alloc_migration_target(struct page *page, unsigned long private); > -extern int isolate_movable_page(struct page *page, isolate_mode_t mode); > +extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); You can drop the 'extern' here. > +++ b/mm/memory_hotplug.c > @@ -1668,18 +1668,18 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > * We can skip free pages. And we can deal with pages on > * LRU and non-lru movable pages. > */ > - if (PageLRU(page)) { > + if (PageLRU(page)) > isolated = isolate_lru_page(page); > - ret = isolated ? 0 : -EBUSY; > - } else > - ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); > - if (!ret) { /* Success */ > + else > + isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE); > + if (isolated) { /* Success */ I would have dropped the "/* Success */" here. Before, commenting "!ret" is quite sensible, but "isolated" seems obviously success to me. Thanks for doing all this.
On 2/15/2023 11:44 PM, Matthew Wilcox wrote: > On Wed, Feb 15, 2023 at 06:39:37PM +0800, Baolin Wang wrote: >> Now the isolate_movable_page() can only return 0 or -EBUSY, and no users >> will care about the negative return value, thus we can convert the >> isolate_movable_page() to return a boolean value to make the code more >> clear when checking the movable page isolation state. >> >> No functional changes intended. >> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> Acked-by: David Hildenbrand <david@redhat.com> > > Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> > > A couple of nits below, not worth respinning the patch series for: > >> diff --git a/include/linux/migrate.h b/include/linux/migrate.h >> index c88b96b48be7..6b252f519c86 100644 >> --- a/include/linux/migrate.h >> +++ b/include/linux/migrate.h >> @@ -71,7 +71,7 @@ extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, >> unsigned long private, enum migrate_mode mode, int reason, >> unsigned int *ret_succeeded); >> extern struct page *alloc_migration_target(struct page *page, unsigned long private); >> -extern int isolate_movable_page(struct page *page, isolate_mode_t mode); >> +extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); > > You can drop the 'extern' here. > >> +++ b/mm/memory_hotplug.c >> @@ -1668,18 +1668,18 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) >> * We can skip free pages. And we can deal with pages on >> * LRU and non-lru movable pages. >> */ >> - if (PageLRU(page)) { >> + if (PageLRU(page)) >> isolated = isolate_lru_page(page); >> - ret = isolated ? 0 : -EBUSY; >> - } else >> - ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); >> - if (!ret) { /* Success */ >> + else >> + isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE); >> + if (isolated) { /* Success */ > > I would have dropped the "/* Success */" here. Before, commenting > "!ret" is quite sensible, but "isolated" seems obviously success to me. Right. Hope Andrew can help to drop this unnecessary comment:) Thanks for reviewing.
On Wed, 15 Feb 2023 15:44:22 +0000 Matthew Wilcox <willy@infradead.org> wrote: > > extern struct page *alloc_migration_target(struct page *page, unsigned long private); > > -extern int isolate_movable_page(struct page *page, isolate_mode_t mode); > > +extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); > > You can drop the 'extern' here. There are a bunch of them, so a separate patch would be better. --- a/include/linux/migrate.h~a +++ a/include/linux/migrate.h @@ -62,16 +62,16 @@ extern const char *migrate_reason_names[ #ifdef CONFIG_MIGRATION -extern void putback_movable_pages(struct list_head *l); +void putback_movable_pages(struct list_head *l); int migrate_folio_extra(struct address_space *mapping, struct folio *dst, struct folio *src, enum migrate_mode mode, int extra_count); int migrate_folio(struct address_space *mapping, struct folio *dst, struct folio *src, enum migrate_mode mode); -extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, - unsigned long private, enum migrate_mode mode, int reason, - unsigned int *ret_succeeded); -extern struct page *alloc_migration_target(struct page *page, unsigned long private); -extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); +int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, + unsigned long private, enum migrate_mode mode, int reason, + unsigned int *ret_succeeded); +struct page *alloc_migration_target(struct page *page, unsigned long private); +bool isolate_movable_page(struct page *page, isolate_mode_t mode); int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src); @@ -142,8 +142,8 @@ const struct movable_operations *page_mo } #ifdef CONFIG_NUMA_BALANCING -extern int migrate_misplaced_page(struct page *page, - struct vm_area_struct *vma, int node); +int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, + int node); #else static inline int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, int node)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index c88b96b48be7..6b252f519c86 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -71,7 +71,7 @@ extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free, unsigned long private, enum migrate_mode mode, int reason, unsigned int *ret_succeeded); extern struct page *alloc_migration_target(struct page *page, unsigned long private); -extern int isolate_movable_page(struct page *page, isolate_mode_t mode); +extern bool isolate_movable_page(struct page *page, isolate_mode_t mode); int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src); @@ -92,8 +92,8 @@ static inline int migrate_pages(struct list_head *l, new_page_t new, static inline struct page *alloc_migration_target(struct page *page, unsigned long private) { return NULL; } -static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) - { return -EBUSY; } +static inline bool isolate_movable_page(struct page *page, isolate_mode_t mode) + { return false; } static inline int migrate_huge_page_move_mapping(struct address_space *mapping, struct folio *dst, struct folio *src) diff --git a/mm/compaction.c b/mm/compaction.c index d73578af44cc..ad7409f70519 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -976,7 +976,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, locked = NULL; } - if (!isolate_movable_page(page, mode)) + if (isolate_movable_page(page, mode)) goto isolate_success; } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 8604753bc644..a1ede7bdce95 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2515,8 +2515,8 @@ static bool isolate_page(struct page *page, struct list_head *pagelist) if (lru) isolated = isolate_lru_page(page); else - isolated = !isolate_movable_page(page, - ISOLATE_UNEVICTABLE); + isolated = isolate_movable_page(page, + ISOLATE_UNEVICTABLE); if (isolated) { list_add(&page->lru, pagelist); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 5fc2dcf4e3ab..bcb0dc41c2f2 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1668,18 +1668,18 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * We can skip free pages. And we can deal with pages on * LRU and non-lru movable pages. */ - if (PageLRU(page)) { + if (PageLRU(page)) isolated = isolate_lru_page(page); - ret = isolated ? 0 : -EBUSY; - } else - ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); - if (!ret) { /* Success */ + else + isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE); + if (isolated) { /* Success */ list_add_tail(&page->lru, &source); if (!__PageMovable(page)) inc_node_page_state(page, NR_ISOLATED_ANON + page_is_file_lru(page)); } else { + ret = -EBUSY; if (__ratelimit(&migrate_rs)) { pr_warn("failed to isolate pfn %lx\n", pfn); dump_page(page, "isolation failed"); diff --git a/mm/migrate.c b/mm/migrate.c index 2db546a0618c..9a101c7bb8ff 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -58,7 +58,7 @@ #include "internal.h" -int isolate_movable_page(struct page *page, isolate_mode_t mode) +bool isolate_movable_page(struct page *page, isolate_mode_t mode) { struct folio *folio = folio_get_nontail_page(page); const struct movable_operations *mops; @@ -119,14 +119,14 @@ int isolate_movable_page(struct page *page, isolate_mode_t mode) folio_set_isolated(folio); folio_unlock(folio); - return 0; + return true; out_no_isolated: folio_unlock(folio); out_putfolio: folio_put(folio); out: - return -EBUSY; + return false; } static void putback_movable_folio(struct folio *folio)