The patch titled Subject: mm/page_alloc: avoid unneeded alike_pages calculation has been added to the -mm mm-unstable branch. Its filename is mm-page_alloc-avoid-unneeded-alike_pages-calculation.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-avoid-unneeded-alike_pages-calculation.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: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/page_alloc: avoid unneeded alike_pages calculation Date: Tue, 1 Aug 2023 20:37:23 +0800 When free_pages is 0, alike_pages is not used. So alike_pages calculation can be avoided by checking free_pages early to save cpu cycles. Also fix typo 'comparable'. It should be 'compatible' here. Link: https://lkml.kernel.org/r/20230801123723.2225543-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-avoid-unneeded-alike_pages-calculation +++ a/mm/page_alloc.c @@ -1833,6 +1833,10 @@ static void steal_suitable_fallback(stru free_pages = move_freepages_block(zone, page, start_type, &movable_pages); + /* moving whole block can fail due to zone boundary conditions */ + if (!free_pages) + goto single_page; + /* * Determine how many pages are compatible with our allocation. * For movable allocation, it's the number of movable pages which @@ -1854,14 +1858,9 @@ static void steal_suitable_fallback(stru else alike_pages = 0; } - - /* moving whole block can fail due to zone boundary conditions */ - if (!free_pages) - goto single_page; - /* * If a sufficient number of pages in the block are either free or of - * comparable migratability as our allocation, claim the whole block. + * compatible migratability as our allocation, claim the whole block. */ if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || page_group_by_mobility_disabled) _ Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page.patch mm-memory-failure-fix-potential-unexpected-return-value-from-unpoison_memory.patch mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch mm-mm_initc-update-obsolete-comment-in-get_pfn_range_for_nid.patch mm-memory-failure-fix-unexpected-return-value-in-soft_offline_page.patch mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch mm-memory-failure-remove-unneeded-page-state-check-in-shake_page.patch memory-tier-use-helper-function-destroy_memory_type.patch mm-memory-failure-remove-unneeded-inline-annotation.patch mm-mm_initc-remove-obsolete-macro-hash_small.patch mm-page_alloc-avoid-false-page-outside-zone-error-info.patch memory-tier-rename-destroy_memory_type-to-put_memory_type.patch mm-remove-obsolete-comment-above-struct-per_cpu_pages.patch mm-memcg-minor-cleanup-for-mem_cgroup_id_max.patch mm-memory-failure-remove-unneeded-pagehuge-check.patch mm-memory-failure-ensure-moving-hwpoison-flag-to-the-raw-error-pages.patch mm-memory-failure-dont-account-hwpoison_filter-filtered-pages.patch mm-memory-failure-use-local-variable-huge-to-check-hugetlb-page.patch mm-memory-failure-remove-unneeded-header-files.patch mm-memory-failure-minor-cleanup-for-comments-and-codestyle.patch mm-memory-failure-fetch-compound-head-after-extra-page-refcnt-is-held.patch mm-memory-failure-fix-race-window-when-trying-to-get-hugetlb-folio.patch mm-huge_memory-use-rmap_none-when-calling-page_add_anon_rmap.patch mm-memcg-fix-obsolete-comment-above-mem_cgroup_max_reclaim_loops.patch mm-memcg-minor-cleanup-for-mc_handle_present_pte.patch memory-tier-use-helper-macro-__attr_rw.patch mm-fix-obsolete-function-name-above-debug_pagealloc_enabled_static.patch mm-mprotect-fix-obsolete-function-name-in-change_pte_range.patch mm-memcg-fix-obsolete-function-name-in-mem_cgroup_protection.patch mm-memory-failure-add-pageoffline-check.patch mm-page_alloc-avoid-unneeded-alike_pages-calculation.patch