The patch titled
mm-modify-swap_map-and-add-swap_has_cache-flag-update
has been added to the -mm tree. Its filename is
mm-modify-swap_map-and-add-swap_has_cache-flag-update.patch
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------------------------------------------------------
Subject: mm-modify-swap_map-and-add-swap_has_cache-flag-update
Several style fix are done....maybe easier to read.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Dhaval Giani <dhaval@xxxxxxxxxxxxxxxxxx>
Cc: YAMAMOTO Takashi <yamamoto@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 67 ++++++++++++++++++++++++++++--------------------
1 file changed, 40 insertions(+), 27 deletions(-)
diff -puN mm/swapfile.c~mm-modify-swap_map-and-add-swap_has_cache-flag-update mm/swapfile.c
--- a/mm/swapfile.c~mm-modify-swap_map-and-add-swap_has_cache-flag-update
+++ a/mm/swapfile.c
@@ -54,17 +54,23 @@ static struct swap_info_struct swap_info
static DEFINE_MUTEX(swapon_mutex);
/* For reference count accounting in swap_map */
+/* enum for swap_map[] handling. internal use only */
+enum {
+ SWAP_MAP = 0, /* ops for reference from swap users */
+ SWAP_CACHE, /* ops for reference from swap cache */
+};
+
static inline int swap_count(unsigned short ent)
{
return ent & SWAP_COUNT_MASK;
}
-static inline int swap_has_cache(unsigned short ent)
+static inline bool swap_has_cache(unsigned short ent)
{
- return ent & SWAP_HAS_CACHE;
+ return !!(ent & SWAP_HAS_CACHE);
}
-static inline unsigned short make_swap_count(int count, int has_cache)
+static inline unsigned short encode_swapmap(int count, bool has_cache)
{
unsigned short ret = count;
@@ -73,6 +79,7 @@ static inline unsigned short make_swap_c
return ret;
}
+
/*
* We need this because the bdev->unplug_fn can sleep and we cannot
* hold swap_lock while calling the unplug_fn. And swap_lock
@@ -306,10 +313,10 @@ checks:
si->lowest_bit = si->max;
si->highest_bit = 0;
}
- if (cache) /* at usual swap-out via vmscan.c */
- si->swap_map[offset] = make_swap_count(0, 1);
+ if (cache == SWAP_CACHE) /* at usual swap-out via vmscan.c */
+ si->swap_map[offset] = encode_swapmap(0, true);
else /* at suspend */
- si->swap_map[offset] = make_swap_count(1, 0);
+ si->swap_map[offset] = encode_swapmap(1, false);
si->cluster_next = offset + 1;
si->flags -= SWP_SCANNING;
@@ -426,7 +433,7 @@ swp_entry_t get_swap_page(void)
swap_list.next = next;
/* This is called for allocating swap entry for cache */
- offset = scan_swap_map(si, 1);
+ offset = scan_swap_map(si, SWAP_CACHE);
if (offset) {
spin_unlock(&swap_lock);
return swp_entry(type, offset);
@@ -451,7 +458,7 @@ swp_entry_t get_swap_page_of_type(int ty
if (si->flags & SWP_WRITEOK) {
nr_swap_pages--;
/* This is called for allocating swap entry, not cache */
- offset = scan_swap_map(si, 0);
+ offset = scan_swap_map(si, SWAP_MAP);
if (offset) {
spin_unlock(&swap_lock);
return swp_entry(type, offset);
@@ -503,16 +510,18 @@ static int swap_entry_free(struct swap_i
{
unsigned long offset = swp_offset(ent);
int count = swap_count(p->swap_map[offset]);
- int has_cache = swap_has_cache(p->swap_map[offset]);
+ bool has_cache;
+
+ has_cache = swap_has_cache(p->swap_map[offset]);
- if (!cache) { /* dropping usage count of swap */
+ if (cache == SWAP_MAP) { /* dropping usage count of swap */
if (count < SWAP_MAP_MAX) {
count--;
- p->swap_map[offset] = make_swap_count(count, has_cache);
+ p->swap_map[offset] = encode_swapmap(count, has_cache);
}
} else { /* dropping swap cache flag */
VM_BUG_ON(!has_cache);
- p->swap_map[offset] = make_swap_count(count, 0);
+ p->swap_map[offset] = encode_swapmap(count, false);
}
/* return code. */
@@ -542,7 +551,7 @@ void swap_free(swp_entry_t entry)
p = swap_info_get(entry);
if (p) {
- swap_entry_free(p, entry, 0);
+ swap_entry_free(p, entry, SWAP_MAP);
spin_unlock(&swap_lock);
}
}
@@ -558,7 +567,7 @@ void swapcache_free(swp_entry_t entry, s
mem_cgroup_uncharge_swapcache(page, entry);
p = swap_info_get(entry);
if (p) {
- swap_entry_free(p, entry, 1);
+ swap_entry_free(p, entry, SWAP_CACHE);
spin_unlock(&swap_lock);
}
return;
@@ -638,7 +647,7 @@ int free_swap_and_cache(swp_entry_t entr
p = swap_info_get(entry);
if (p) {
- if (swap_entry_free(p, entry, 0) == SWAP_HAS_CACHE) {
+ if (swap_entry_free(p, entry, SWAP_MAP) == SWAP_HAS_CACHE) {
page = find_get_page(&swapper_space, entry.val);
if (page && !trylock_page(page)) {
page_cache_release(page);
@@ -1131,7 +1140,7 @@ static int try_to_unuse(unsigned int typ
if (swap_count(*swap_map) == SWAP_MAP_MAX) {
spin_lock(&swap_lock);
- *swap_map = make_swap_count(0, 1);
+ *swap_map = encode_swapmap(0, true);
spin_unlock(&swap_lock);
reset_overflow = 1;
}
@@ -2011,12 +2020,13 @@ void si_swapinfo(struct sysinfo *val)
* - swap-cache reference is requested but there is already one. -> EEXIST
* - swap-cache reference is requested but the entry is not used. -> ENOENT
*/
-static int __swap_duplicate(swp_entry_t entry, int cache)
+static int __swap_duplicate(swp_entry_t entry, bool cache)
{
struct swap_info_struct * p;
unsigned long offset, type;
int result = -EINVAL;
- int count, has_cache;
+ int count;
+ bool has_cache;
if (is_migration_entry(entry))
return -EINVAL;
@@ -2034,25 +2044,28 @@ static int __swap_duplicate(swp_entry_t
count = swap_count(p->swap_map[offset]);
has_cache = swap_has_cache(p->swap_map[offset]);
- if (cache) { /* called for swapcache/swapin-readahead */
+
+ if (cache == SWAP_CACHE) { /* called for swapcache/swapin-readahead */
+
/* set SWAP_HAS_CACHE if there is no cache and entry is used */
if (!has_cache && count) {
- p->swap_map[offset] = make_swap_count(count, 1);
+ p->swap_map[offset] = encode_swapmap(count, true);
result = 0;
- } else if (has_cache)
+ } else if (has_cache) /* someone added cache */
result = -EEXIST;
- else if (!count)
+ else if (!count) /* no users */
result = -ENOENT;
+
} else if (count || has_cache) {
if (count < SWAP_MAP_MAX - 1) {
- p->swap_map[offset] = make_swap_count(count + 1,
- has_cache);
+ p->swap_map[offset] = encode_swapmap(count + 1,
+ has_cache);
result = 0;
} else if (count <= SWAP_MAP_MAX) {
if (swap_overflow++ < 5)
printk(KERN_WARNING
"swap_dup: swap entry overflow\n");
- p->swap_map[offset] = make_swap_count(SWAP_MAP_MAX,
+ p->swap_map[offset] = encode_swapmap(SWAP_MAP_MAX,
has_cache);
result = 0;
}
@@ -2072,7 +2085,7 @@ bad_file:
*/
void swap_duplicate(swp_entry_t entry)
{
- __swap_duplicate(entry, 0);
+ __swap_duplicate(entry, SWAP_MAP);
}
/*
@@ -2085,7 +2098,7 @@ void swap_duplicate(swp_entry_t entry)
*/
int swapcache_prepare(swp_entry_t entry)
{
- return __swap_duplicate(entry, 1);
+ return __swap_duplicate(entry, SWAP_CACHE);
}
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
origin.patch
migration-only-migrate_prep-once-per-move_pages.patch
page-allocator-use-integer-fields-lookup-for-gfp_zone-and-check-for-errors-in-flags-passed-to-the-page-allocator.patch
page-allocator-use-integer-fields-lookup-for-gfp_zone-and-check-for-errors-in-flags-passed-to-the-page-allocator-fix-gfp-zone-patch.patch
mm-add-swap-cache-interface-for-swap-reference.patch
mm-modify-swap_map-and-add-swap_has_cache-flag.patch
mm-modify-swap_map-and-add-swap_has_cache-flag-update.patch
mm-reuse-unused-swap-entry-if-necessary.patch
mm-reuse-unused-swap-entry-if-necessary-update.patch
cgroups-forbid-noprefix-if-mounting-more-than-just-cpuset-subsystem.patch
cgroups-forbid-noprefix-if-mounting-more-than-just-cpuset-subsystem-fix.patch
cgroups-forbid-noprefix-if-mounting-more-than-just-cpuset-subsystem-fix2.patch
memcg-add-file-based-rss-accounting.patch
memcg-add-file-based-rss-accounting-fix-mem_cgroup_update_mapped_file_stat-oops.patch
memcg-remove-mem_cgroup_cache_charge_swapin.patch
memcg-remove-some-redundant-checks.patch
memcg-remove-unneeded-forward-declaration-from-schedh.patch
memcg-fix-swap-accounting.patch
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