On 04.06.24 06:24, alexs@xxxxxxxxxx wrote:
From: "Alex Shi (tencent)" <alexs@xxxxxxxxxx> To replace pages_identical() func and further reduce the 'page' using in try_to_merge_one_page function. Signed-off-by: Alex Shi (tencent) <alexs@xxxxxxxxxx> --- include/linux/mm.h | 17 +++++++++++++++++ mm/ksm.c | 2 +- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 9849dfda44d4..2d1f16ffc6ac 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4164,6 +4164,23 @@ static inline void setup_nr_node_ids(void) {}extern int memcmp_pages(struct page *page1, struct page *page2); +static inline int identical_folio(struct folio *folio1, struct folio *folio2)+{ + int i, nr1, nr2, ret = 0; + + nr1 = folio_nr_pages(folio1); + nr2 = folio_nr_pages(folio2); + if (nr1 != nr2) + return 0; + + for (i = 0; i < nr1; i++) { + ret = memcmp_pages(folio_page(folio1, i), folio_page(folio2, i)); + if (ret) + break; + } + + return !ret; +}
We never get there with large folios. So handling large folios is completely unnecessary.
Keep it simple: either VM_WARN_ON_ONCE when a large folio is passed, or simply return "false". Then, check only a single page.
-- Cheers, David / dhildenb
