unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

mm/writeback: minor clean up for highmem_dirtyable_memory

Browse source 
Since commit a804552b9a ("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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Miaohe Lin 2022-03-22 14:39:31 -07:00 committed by Linus Torvalds
parent eb5279fb7e
commit 854d8e3616
1 changed files with 0 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
mm/page-writeback.c
View file

@ -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