Commit 854d8e36 authored by Miaohe Lin's avatar Miaohe Lin Committed by Linus Torvalds
Browse files

mm/writeback: minor clean up for highmem_dirtyable_memory 

Since commit a804552b ("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: default avatarMiaohe Lin <linmiaohe@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent eb5279fb

mm/page-writeback.c

+0 −12
Original line number Diff line number Diff line
@@ -323,18 +323,6 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) 
		}

	}



	/*

	 * 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