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-rw-r--r--mm/swapfile.c77
1 files changed, 61 insertions, 16 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 2cc2972eedaf..8837b22c848d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2909,6 +2909,35 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode)
return 0;
}
+
+/*
+ * Find out how many pages are allowed for a single swap device. There
+ * are two limiting factors:
+ * 1) the number of bits for the swap offset in the swp_entry_t type, and
+ * 2) the number of bits in the swap pte, as defined by the different
+ * architectures.
+ *
+ * In order to find the largest possible bit mask, a swap entry with
+ * swap type 0 and swap offset ~0UL is created, encoded to a swap pte,
+ * decoded to a swp_entry_t again, and finally the swap offset is
+ * extracted.
+ *
+ * This will mask all the bits from the initial ~0UL mask that can't
+ * be encoded in either the swp_entry_t or the architecture definition
+ * of a swap pte.
+ */
+unsigned long generic_max_swapfile_size(void)
+{
+ return swp_offset(pte_to_swp_entry(
+ swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
+}
+
+/* Can be overridden by an architecture for additional checks. */
+__weak unsigned long max_swapfile_size(void)
+{
+ return generic_max_swapfile_size();
+}
+
static unsigned long read_swap_header(struct swap_info_struct *p,
union swap_header *swap_header,
struct inode *inode)
@@ -2944,22 +2973,7 @@ static unsigned long read_swap_header(struct swap_info_struct *p,
p->cluster_next = 1;
p->cluster_nr = 0;
- /*
- * Find out how many pages are allowed for a single swap
- * device. There are two limiting factors: 1) the number
- * of bits for the swap offset in the swp_entry_t type, and
- * 2) the number of bits in the swap pte as defined by the
- * different architectures. In order to find the
- * largest possible bit mask, a swap entry with swap type 0
- * and swap offset ~0UL is created, encoded to a swap pte,
- * decoded to a swp_entry_t again, and finally the swap
- * offset is extracted. This will mask all the bits from
- * the initial ~0UL mask that can't be encoded in either
- * the swp_entry_t or the architecture definition of a
- * swap pte.
- */
- maxpages = swp_offset(pte_to_swp_entry(
- swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
+ maxpages = max_swapfile_size();
last_page = swap_header->info.last_page;
if (!last_page) {
pr_warn("Empty swap-file\n");
@@ -3731,6 +3745,37 @@ static void free_swap_count_continuations(struct swap_info_struct *si)
}
}
+#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
+void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node,
+ gfp_t gfp_mask)
+{
+ struct swap_info_struct *si, *next;
+ if (!(gfp_mask & __GFP_IO) || !memcg)
+ return;
+
+ if (!blk_cgroup_congested())
+ return;
+
+ /*
+ * We've already scheduled a throttle, avoid taking the global swap
+ * lock.
+ */
+ if (current->throttle_queue)
+ return;
+
+ spin_lock(&swap_avail_lock);
+ plist_for_each_entry_safe(si, next, &swap_avail_heads[node],
+ avail_lists[node]) {
+ if (si->bdev) {
+ blkcg_schedule_throttle(bdev_get_queue(si->bdev),
+ true);
+ break;
+ }
+ }
+ spin_unlock(&swap_avail_lock);
+}
+#endif
+
static int __init swapfile_init(void)
{
int nid;