+ mm-writeback-minor-clean-up-for-highmem_dirtyable_memory.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

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

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
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@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@huawei.com 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