Commit 99b12e3d authored Jul 25, 2011 by Wu Fengguang Committed by Linus Torvalds Jul 25, 2011

writeback: account NR_WRITTEN at IO completion time



NR_WRITTEN is now accounted at block IO enqueue time, which is not very
accurate as to common understanding.  This moves NR_WRITTEN accounting to
the IO completion time and makes it more consistent with BDI_WRITTEN,
which is used for bandwidth estimation.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 48f170fb

mm/page-writeback.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1141,7 +1141,6 @@ EXPORT_SYMBOL(account_page_dirtied);
		void account_page_writeback(struct page *page)
		{
		inc_zone_page_state(page, NR_WRITEBACK);
		inc_zone_page_state(page, NR_WRITTEN);
		}
		EXPORT_SYMBOL(account_page_writeback);

		@@ -1358,8 +1357,10 @@ int test_clear_page_writeback(struct page *page)
		} else {
		ret = TestClearPageWriteback(page);
		}
		if (ret)
		if (ret) {
		dec_zone_page_state(page, NR_WRITEBACK);
		inc_zone_page_state(page, NR_WRITTEN);
		}
		return ret;
		}

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