mm, swap, get_swap_pages: use entry_size instead of cluster in parameter
As suggested by Matthew Wilcox, it is better to use "int entry_size"
instead of "bool cluster" as parameter to specify whether to operate for
huge or normal swap entries. Because this improve the flexibility to
support other swap entry size. And Dave Hansen thinks that this
improves code readability too.
So in this patch, the "bool cluster" parameter of get_swap_pages() is
replaced by "int entry_size".
And nr_swap_entries() trick is used to reduce the binary size when
!CONFIG_TRANSPARENT_HUGE_PAGE.
text data bss dec hex filename
base 24215 2028 340 26583 67d7 mm/swapfile.o
head 24123 2004 340 26467 6763 mm/swapfile.o
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: "Huang, Ying" <[email protected]>
Suggested-by: Matthew Wilcox <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Cc: Daniel Jordan <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Dan Williams <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 043645e..b30dd06 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -940,18 +940,18 @@ static unsigned long scan_swap_map(struct swap_info_struct *si,
}
-int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
+int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
{
- unsigned long nr_pages = cluster ? SWAPFILE_CLUSTER : 1;
+ unsigned long size = swap_entry_size(entry_size);
struct swap_info_struct *si, *next;
long avail_pgs;
int n_ret = 0;
int node;
/* Only single cluster request supported */
- WARN_ON_ONCE(n_goal > 1 && cluster);
+ WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
- avail_pgs = atomic_long_read(&nr_swap_pages) / nr_pages;
+ avail_pgs = atomic_long_read(&nr_swap_pages) / size;
if (avail_pgs <= 0)
goto noswap;
@@ -961,7 +961,7 @@ int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
if (n_goal > avail_pgs)
n_goal = avail_pgs;
- atomic_long_sub(n_goal * nr_pages, &nr_swap_pages);
+ atomic_long_sub(n_goal * size, &nr_swap_pages);
spin_lock(&swap_avail_lock);
@@ -988,14 +988,14 @@ int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
spin_unlock(&si->lock);
goto nextsi;
}
- if (cluster) {
+ if (size == SWAPFILE_CLUSTER) {
if (!(si->flags & SWP_FILE))
n_ret = swap_alloc_cluster(si, swp_entries);
} else
n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
n_goal, swp_entries);
spin_unlock(&si->lock);
- if (n_ret || cluster)
+ if (n_ret || size == SWAPFILE_CLUSTER)
goto check_out;
pr_debug("scan_swap_map of si %d failed to find offset\n",
si->type);
@@ -1021,7 +1021,7 @@ int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
check_out:
if (n_ret < n_goal)
- atomic_long_add((long)(n_goal - n_ret) * nr_pages,
+ atomic_long_add((long)(n_goal - n_ret) * size,
&nr_swap_pages);
noswap:
return n_ret;
