The function just return 2 results, so use a 'switch' to deal with its result is unnecessary, and simplify it to a bool func as Vlastimil suggested.
Also removed 'goto' in using by reusing list_move(). Signed-off-by: Alex Shi <alex....@linux.alibaba.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Hugh Dickins <hu...@google.com> Cc: Yu Zhao <yuz...@google.com> Cc: Vlastimil Babka <vba...@suse.cz> Cc: Michal Hocko <mho...@suse.com> Cc: linux...@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/compaction.c | 2 +- mm/vmscan.c | 53 ++++++++++++++++++++++++------------------------- 2 files changed, 27 insertions(+), 28 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index b68931854253..8d71ffebe6cb 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -988,7 +988,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (unlikely(!get_page_unless_zero(page))) goto isolate_fail; - if (__isolate_lru_page_prepare(page, isolate_mode) != 0) + if (!__isolate_lru_page_prepare(page, isolate_mode)) goto isolate_fail_put; /* Try isolate the page */ diff --git a/mm/vmscan.c b/mm/vmscan.c index c6f94e55c3fe..7f32c1979804 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1540,7 +1540,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone, */ int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode) { - int ret = -EBUSY; + int ret = false; /* Only take pages on the LRU. */ if (!PageLRU(page)) @@ -1590,7 +1590,7 @@ int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode) if ((mode & ISOLATE_UNMAPPED) && page_mapped(page)) return ret; - return 0; + return true; } /* @@ -1674,35 +1674,34 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, * only when the page is being freed somewhere else. */ scan += nr_pages; - switch (__isolate_lru_page_prepare(page, mode)) { - case 0: + if (!__isolate_lru_page_prepare(page, mode)) { + /* else it is being freed elsewhere */ + list_move(&page->lru, src); + continue; + } + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) { + list_move(&page->lru, src); + continue; + } + + if (!TestClearPageLRU(page)) { /* - * Be careful not to clear PageLRU until after we're - * sure the page is not being freed elsewhere -- the - * page release code relies on it. + * This page may in other isolation path, + * but we still hold lru_lock. */ - if (unlikely(!get_page_unless_zero(page))) - goto busy; - - if (!TestClearPageLRU(page)) { - /* - * This page may in other isolation path, - * but we still hold lru_lock. - */ - put_page(page); - goto busy; - } - - nr_taken += nr_pages; - nr_zone_taken[page_zonenum(page)] += nr_pages; - list_move(&page->lru, dst); - break; - - default: -busy: - /* else it is being freed elsewhere */ + put_page(page); list_move(&page->lru, src); + continue; } + + nr_taken += nr_pages; + nr_zone_taken[page_zonenum(page)] += nr_pages; + list_move(&page->lru, dst); } /* -- 2.29.GIT