The patch titled Subject: mm/page_alloc: remove unused fpi_flags in free_pages_prepare() has been added to the -mm mm-unstable branch. Its filename is mm-page_alloc-remove-unused-fpi_flags-in-free_pages_prepare.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-remove-unused-fpi_flags-in-free_pages_prepare.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Zi Yan <ziy@xxxxxxxxxx> Subject: mm/page_alloc: remove unused fpi_flags in free_pages_prepare() Date: Tue, 20 Feb 2024 13:32:17 -0500 Patch series "Enable >0 order folio memory compaction", v7. This patchset enables >0 order folio memory compaction, which is one of the prerequisitions for large folio support[1]. I am aware of that split free pages is necessary for folio migration in compaction, since if >0 order free pages are never split and no order-0 free page is scanned, compaction will end prematurely due to migration returns -ENOMEM. Free page split becomes a must instead of an optimization. lkp ncompare results (on a 8-CPU (Intel Xeon E5-2650 v4 @2.20GHz) 16G VM) for default LRU (-no-mglru) and CONFIG_LRU_GEN are shown at the bottom, copied from V3[4]. In sum, most of vm-scalability applications do not see performance change, and the others see ~4% to ~26% performance boost under default LRU and ~2% to ~6% performance boost under CONFIG_LRU_GEN. Overview === To support >0 order folio compaction, the patchset changes how free pages used for migration are kept during compaction. Free pages used to be split into order-0 pages that are post allocation processed (i.e., PageBuddy flag cleared, page order stored in page->private is zeroed, and page reference is set to 1). Now all free pages are kept in a NR_PAGE_ORDER array of page lists based on their order without post allocation process. When migrate_pages() asks for a new page, one of the free pages, based on the requested page order, is then processed and given out. And THP <2MB would need this feature. [1] https://lore.kernel.org/linux-mm/f8d47176-03a8-99bf-a813-b5942830fd73@xxxxxxx/ [2] https://lore.kernel.org/linux-mm/20231113170157.280181-1-zi.yan@xxxxxxxx/ [3] https://lore.kernel.org/linux-mm/20240123034636.1095672-1-zi.yan@xxxxxxxx/ [4] https://lore.kernel.org/linux-mm/20240202161554.565023-1-zi.yan@xxxxxxxx/ [5] https://lore.kernel.org/linux-mm/20240212163510.859822-1-zi.yan@xxxxxxxx/ [6] https://lore.kernel.org/linux-mm/20240214220420.1229173-1-zi.yan@xxxxxxxx/ [7] https://lore.kernel.org/linux-mm/20240216170432.1268753-1-zi.yan@xxxxxxxx/ This patch (of 4): Commit 0a54864f8dfb ("kasan: remove PG_skip_kasan_poison flag") removes the use of fpi_flags in should_skip_kasan_poison() and fpi_flags is only passed to should_skip_kasan_poison() in free_pages_prepare(). Remove the unused parameter. Link: https://lkml.kernel.org/r/20240220183220.1451315-1-zi.yan@xxxxxxxx Link: https://lkml.kernel.org/r/20240220183220.1451315-2-zi.yan@xxxxxxxx Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Adam Manzanares <a.manzanares@xxxxxxxxxxx> Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Ryan Roberts <ryan.roberts@xxxxxxx> Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx> Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx> Cc: Yu Zhao <yuzhao@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-remove-unused-fpi_flags-in-free_pages_prepare +++ a/mm/page_alloc.c @@ -1061,7 +1061,7 @@ out: * on-demand allocation and then freed again before the deferred pages * initialization is done, but this is not likely to happen. */ -static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) +static inline bool should_skip_kasan_poison(struct page *page) { if (IS_ENABLED(CONFIG_KASAN_GENERIC)) return deferred_pages_enabled(); @@ -1081,10 +1081,10 @@ static void kernel_init_pages(struct pag } static __always_inline bool free_pages_prepare(struct page *page, - unsigned int order, fpi_t fpi_flags) + unsigned int order) { int bad = 0; - bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); + bool skip_kasan_poison = should_skip_kasan_poison(page); bool init = want_init_on_free(); bool compound = PageCompound(page); @@ -1266,7 +1266,7 @@ static void __free_pages_ok(struct page unsigned long pfn = page_to_pfn(page); struct zone *zone = page_zone(page); - if (!free_pages_prepare(page, order, fpi_flags)) + if (!free_pages_prepare(page, order)) return; /* @@ -2343,7 +2343,7 @@ static bool free_unref_page_prepare(stru { int migratetype; - if (!free_pages_prepare(page, order, FPI_NONE)) + if (!free_pages_prepare(page, order)) return false; migratetype = get_pfnblock_migratetype(page, pfn); _ Patches currently in -mm which might be from ziy@xxxxxxxxxx are mm-page_alloc-remove-unused-fpi_flags-in-free_pages_prepare.patch mm-compaction-enable-compacting-0-order-folios.patch mm-compaction-add-support-for-0-order-folio-memory-compaction.patch mm-compaction-optimize-0-order-folio-compaction-with-free-page-split.patch