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mm/swapfile.c: optimize code in setup_clusters()

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In the last 'for' loop inside setup_clusters(), using two local variable
'k' and 'j' are obvisouly redundant.  Using 'j' is enough and simpler.

And also move macro SWAP_CLUSTER_COLS close to its only user
setup_clusters().

Link: https://lkml.kernel.org/r/20250205092721.9395-8-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <ryncsn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Baoquan He 2025-02-05 17:27:16 +08:00 committed by Andrew Morton
parent f80ddc148c
commit a46a6bc21c
1 changed files with 9 additions and 10 deletions
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19
mm/swapfile.c
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@ -3127,13 +3127,6 @@ static unsigned long read_swap_header(struct swap_info_struct *si,
return maxpages;
}
#define SWAP_CLUSTER_INFO_COLS \
DIV_ROUND_UP(L1_CACHE_BYTES, sizeof(struct swap_cluster_info))
#define SWAP_CLUSTER_SPACE_COLS \
DIV_ROUND_UP(SWAP_ADDRESS_SPACE_PAGES, SWAPFILE_CLUSTER)
#define SWAP_CLUSTER_COLS \
max_t(unsigned int, SWAP_CLUSTER_INFO_COLS, SWAP_CLUSTER_SPACE_COLS)
static int setup_swap_map_and_extents(struct swap_info_struct *si,
union swap_header *swap_header,
unsigned char *swap_map,
@ -3173,13 +3166,20 @@ static int setup_swap_map_and_extents(struct swap_info_struct *si,
return nr_extents;
}
#define SWAP_CLUSTER_INFO_COLS \
DIV_ROUND_UP(L1_CACHE_BYTES, sizeof(struct swap_cluster_info))
#define SWAP_CLUSTER_SPACE_COLS \
DIV_ROUND_UP(SWAP_ADDRESS_SPACE_PAGES, SWAPFILE_CLUSTER)
#define SWAP_CLUSTER_COLS \
max_t(unsigned int, SWAP_CLUSTER_INFO_COLS, SWAP_CLUSTER_SPACE_COLS)
static struct swap_cluster_info *setup_clusters(struct swap_info_struct *si,
union swap_header *swap_header,
unsigned long maxpages)
{
unsigned long nr_clusters = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
struct swap_cluster_info *cluster_info;
unsigned long i, j, k, idx;
unsigned long i, j, idx;
int cpu, err = -ENOMEM;
cluster_info = kvcalloc(nr_clusters, sizeof(*cluster_info), GFP_KERNEL);
@ -3240,8 +3240,7 @@ static struct swap_cluster_info *setup_clusters(struct swap_info_struct *si,
* Reduce false cache line sharing between cluster_info and
* sharing same address space.
*/
for (k = 0; k < SWAP_CLUSTER_COLS; k++) {
j = k % SWAP_CLUSTER_COLS;
for (j = 0; j < SWAP_CLUSTER_COLS; j++) {
for (i = 0; i < DIV_ROUND_UP(nr_clusters, SWAP_CLUSTER_COLS); i++) {
struct swap_cluster_info *ci;
idx = i * SWAP_CLUSTER_COLS + j;