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mm/swapfile.c: simplify the calculation of n_goal

PATCH Applied Wei Yang 1 participant 2 messages Mar 25, 2020

Subsystems (2)
Memory management MM swap
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Wei Yang

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#0 lore raw

PATCH 1/2 mm/swapfile.c: simplify the calculation of n_goal

Use min3() to simplify the comparison and make it more self-explaining.

Signed-off-by Wei Yang <[email protected]>
---
 mm/swapfile.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
mm/swapfile.c +1 -5
index 2c33ff456ed5..85b151d73128 100644
@@ -1004,11 +1004,7 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
 	if (avail_pgs <= 0)
 		goto noswap;
 
-	if (n_goal > SWAP_BATCH)
-		n_goal = SWAP_BATCH;
-
-	if (n_goal > avail_pgs)
-		n_goal = avail_pgs;
+	n_goal = min3((long)n_goal, (long)SWAP_BATCH, avail_pgs);
 
 	atomic_long_sub(n_goal * size, &nr_swap_pages);
Signature · 1 line
2.23.0
author
#1 lore raw

PATCH 2/2 mm/swapfile.c: remove the extra check in scan_swap_map_slots()

scan_swap_map_slots() is only called by scan_swap_map() and get_swap_pages(). Both ensure nr would not exceed SWAP_BATCH.

Just remove it.

Signed-off-by Wei Yang <[email protected]>
---
 mm/swapfile.c | 3 ---
 1 file changed, 3 deletions(-)
mm/swapfile.c +0 -3
index 85b151d73128..6b6e41967bf3 100644
@@ -740,9 +740,6 @@ static int scan_swap_map_slots(struct swap_info_struct *si,
 	int latency_ration = LATENCY_LIMIT;
 	int n_ret = 0;
 
-	if (nr > SWAP_BATCH)
-		nr = SWAP_BATCH;
-
 	/*
 	 * We try to cluster swap pages by allocating them sequentially
 	 * in swap.  Once we've allocated SWAPFILE_CLUSTER pages this
Signature · 1 line
2.23.0