The patch titled Subject: mm/writeback: minor clean up for highmem_dirtyable_memory has been added to the -mm tree. Its filename is mm-writeback-minor-clean-up-for-highmem_dirtyable_memory.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-writeback-minor-clean-up-for-highmem_dirtyable_memory.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-writeback-minor-clean-up-for-highmem_dirtyable_memory.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/writeback: minor clean up for highmem_dirtyable_memory Since commit a804552b9a15 ("mm/page-writeback.c: fix dirty_balance_reserve subtraction from dirtyable memory"), local variable x can not be negative. And it can not overflow when it is the total number of dirtyable highmem pages. Thus remove the unneeded comment and overflow check. Link: https://lkml.kernel.org/r/20220224115416.46089-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page-writeback.c | 12 ------------ 1 file changed, 12 deletions(-) --- a/mm/page-writeback.c~mm-writeback-minor-clean-up-for-highmem_dirtyable_memory +++ a/mm/page-writeback.c @@ -324,18 +324,6 @@ static unsigned long highmem_dirtyable_m } /* - * Unreclaimable memory (kernel memory or anonymous memory - * without swap) can bring down the dirtyable pages below - * the zone's dirty balance reserve and the above calculation - * will underflow. However we still want to add in nodes - * which are below threshold (negative values) to get a more - * accurate calculation but make sure that the total never - * underflows. - */ - if ((long)x < 0) - x = 0; - - /* * Make sure that the number of highmem pages is never larger * than the number of the total dirtyable memory. This can only * occur in very strange VM situations but we want to make sure _ Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are mm-memremap-avoid-calling-kasan_remove_zero_shadow-for-device-private-memory.patch filemap-remove-find_get_pages.patch mm-writeback-minor-clean-up-for-highmem_dirtyable_memory.patch mm-use-helper-function-range_in_vma.patch mm-use-helper-macro-min-and-max-in-unmap_mapping_range_tree.patch mm-sparse-make-mminit_validate_memmodel_limits-static.patch mm-vmalloc-remove-unneeded-function-forward-declaration.patch mm-mmzoneh-remove-unused-macros.patch mm-memory-failurec-minor-clean-up-for-memory_failure_dev_pagemap.patch mm-memory-failurec-catch-unexpected-efault-from-vma_address.patch mm-memory-failurec-rework-the-signaling-logic-in-kill_proc.patch mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch mm-memory-failurec-remove-pageslab-check-in-hwpoison_filter_dev.patch mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch mm-memory-failurec-remove-obsolete-comment-in-__soft_offline_page.patch mm-memory-failurec-remove-unnecessary-pagetranstail-check.patch mm-hwpoison-inject-support-injecting-hwpoison-to-free-page.patch mm-hugetlb-use-helper-macro-__attr_rw.patch mm-oom_kill-remove-unneeded-is_memcg_oom-check.patch mm-ksm-use-helper-macro-__attr_rw.patch mm-balloon_compaction-make-balloon-page-compaction-callbacks-static.patch mm-memory_hotplug-remove-obsolete-comment-of-__add_pages.patch mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal.patch mm-memory_hotplug-clean-up-try_offline_node.patch mm-memory_hotplug-fix-misplaced-comment-in-offline_pages.patch mm-highmem-remove-unnecessary-done-label.patch mm-hmmc-remove-unneeded-local-variable-ret.patch kernel-ksysfsc-use-helper-macro-__attr_rw.patch kernel-resource-fix-kfree-of-bootmem-memory-again.patch