mm/page-writeback.c: remove outdated comment (d2f31028) · Commits · 戴 / test

There is an orphaned prehistoric comment , which used to be against get_dirty_limits(), the dawn of global_dirtyable_memory(). Back then, the implementation of get_dirty_limits() is complicated and full of magic numbers, so this comment is necessary. But we now use the clear and neat global_dirtyable_memory(), which renders this comment ambiguous and useless. Remove it. Signed-off-by:

Jianyu Zhan <nasa4836@gmail.com> Acked-by:

Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/page-writeback.c

+0 −18

Original line number	Diff line number	Diff line
		@@ -155,24 +155,6 @@ static unsigned long writeout_period_time = 0;
		*/
		#define VM_COMPLETIONS_PERIOD_LEN (3*HZ)

		/*
		* Work out the current dirty-memory clamping and background writeout
		* thresholds.
		*
		* The main aim here is to lower them aggressively if there is a lot of mapped
		* memory around. To avoid stressing page reclaim with lots of unreclaimable
		* pages. It is better to clamp down on writers than to start swapping, and
		* performing lots of scanning.
		*
		* We only allow 1/2 of the currently-unmapped memory to be dirtied.
		*
		* We don't permit the clamping level to fall below 5% - that is getting rather
		* excessive.
		*
		* We make sure that the background writeout level is below the adjusted
		* clamping level.
		*/

		/*
		* In a memory zone, there is a certain amount of pages we consider
		* available for the page cache, which is essentially the number of

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