[PATCH 6/7][TRIVIAL][resend] mm: cleanup page reclaim comment error

Subsystems: memory management, memory management - mglru (multi-gen lru), memory management - reclaim, the rest

STALE5229d REVIEWED: 4 (2M)

3 review trailers.

2 messages, 2 authors, 2012-06-15 · open the first message on its own page

[PATCH 6/7][TRIVIAL][resend] mm: cleanup page reclaim comment error

From: Wanpeng Li <hidden>
Date: 2012-06-15 13:20:18

From: Wanpeng Li <redacted>

Since there are five lists in LRU cache, the array nr in get_scan_count
should be:

nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
nr[2] = file inactive pages to scan; nr[3] = file active pages to scan

Signed-off-by: Wanpeng Li <redacted>
Acked-by: KOSAKI Motohiro <redacted>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Rik van Riel <redacted>

---
 mm/vmscan.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eeb3bc9..ed823df 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c

@@ -1567,7 +1567,8 @@ static int vmscan_swappiness(struct scan_control *sc)
  * by looking at the fraction of the pages scanned we did rotate back
  * onto the active list instead of evict.
  *
- * nr[0] = anon pages to scan; nr[1] = file pages to scan
+ * nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
+ * nr[2] = file inactive pages to scan; nr[3] = file active pages to scan
  */
 static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
 			   unsigned long *nr)

-- 
1.7.9.5

Re: [PATCH 6/7][TRIVIAL][resend] mm: cleanup page reclaim comment error

From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2012-06-15 15:02:27

On Fri, Jun 15, 2012 at 09:19:45PM +0800, Wanpeng Li wrote:

quoted hunk

From: Wanpeng Li <redacted>

Since there are five lists in LRU cache, the array nr in get_scan_count
should be:

nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
nr[2] = file inactive pages to scan; nr[3] = file active pages to scan

Signed-off-by: Wanpeng Li <redacted>
Acked-by: KOSAKI Motohiro <redacted>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Rik van Riel <redacted>

---
 mm/vmscan.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eeb3bc9..ed823df 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c

@@ -1567,7 +1567,8 @@ static int vmscan_swappiness(struct scan_control *sc)
  * by looking at the fraction of the pages scanned we did rotate back
  * onto the active list instead of evict.
  *
- * nr[0] = anon pages to scan; nr[1] = file pages to scan
+ * nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
+ * nr[2] = file inactive pages to scan; nr[3] = file active pages to scan
  */

Does including this in the comment have any merit in the first place?
We never access nr[0] or nr[1] etc. anywhere with magic numbers.  It's
a local function with one callsite, the passed array is declared and
accessed exclusively by what is defined in enum lru_list, where is the
point in repeating the enum items?.  I'd rather the next change to
this comment would be its removal.

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