#include <linux/swap_slots.h>
#include <linux/sort.h>
-#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <linux/swapops.h>
#include <linux/swap_cgroup.h>
{
struct percpu_cluster *cluster;
struct swap_cluster_info *ci;
- bool found_free;
unsigned long tmp, max;
new_cluster:
} else if (!cluster_list_empty(&si->discard_clusters)) {
/*
* we don't have free cluster but have some clusters in
- * discarding, do discard now and reclaim them
+ * discarding, do discard now and reclaim them, then
+ * reread cluster_next_cpu since we dropped si->lock
*/
swap_do_scheduled_discard(si);
- *scan_base = *offset = si->cluster_next;
+ *scan_base = this_cpu_read(*si->cluster_next_cpu);
+ *offset = *scan_base;
goto new_cluster;
} else
return false;
}
- found_free = false;
-
/*
* Other CPUs can use our cluster if they can't find a free cluster,
* check if there is still free entry in the cluster
tmp = cluster->next;
max = min_t(unsigned long, si->max,
(cluster_next(&cluster->index) + 1) * SWAPFILE_CLUSTER);
- if (tmp >= max) {
- cluster_set_null(&cluster->index);
- goto new_cluster;
- }
- ci = lock_cluster(si, tmp);
- while (tmp < max) {
- if (!si->swap_map[tmp]) {
- found_free = true;
- break;
+ if (tmp < max) {
+ ci = lock_cluster(si, tmp);
+ while (tmp < max) {
+ if (!si->swap_map[tmp])
+ break;
+ tmp++;
}
- tmp++;
+ unlock_cluster(ci);
}
- unlock_cluster(ci);
- if (!found_free) {
+ if (tmp >= max) {
cluster_set_null(&cluster->index);
goto new_cluster;
}
cluster->next = tmp + 1;
*offset = tmp;
*scan_base = tmp;
- return found_free;
+ return true;
}
static void __del_from_avail_list(struct swap_info_struct *p)
}
}
+static void set_cluster_next(struct swap_info_struct *si, unsigned long next)
+{
+ unsigned long prev;
+
+ if (!(si->flags & SWP_SOLIDSTATE)) {
+ si->cluster_next = next;
+ return;
+ }
+
+ prev = this_cpu_read(*si->cluster_next_cpu);
+ /*
+ * Cross the swap address space size aligned trunk, choose
+ * another trunk randomly to avoid lock contention on swap
+ * address space if possible.
+ */
+ if ((prev >> SWAP_ADDRESS_SPACE_SHIFT) !=
+ (next >> SWAP_ADDRESS_SPACE_SHIFT)) {
+ /* No free swap slots available */
+ if (si->highest_bit <= si->lowest_bit)
+ return;
+ next = si->lowest_bit +
+ prandom_u32_max(si->highest_bit - si->lowest_bit + 1);
+ next = ALIGN_DOWN(next, SWAP_ADDRESS_SPACE_PAGES);
+ next = max_t(unsigned int, next, si->lowest_bit);
+ }
+ this_cpu_write(*si->cluster_next_cpu, next);
+}
+
static int scan_swap_map_slots(struct swap_info_struct *si,
unsigned char usage, int nr,
swp_entry_t slots[])
unsigned long last_in_cluster = 0;
int latency_ration = LATENCY_LIMIT;
int n_ret = 0;
-
- if (nr > SWAP_BATCH)
- nr = SWAP_BATCH;
+ bool scanned_many = false;
/*
* We try to cluster swap pages by allocating them sequentially
*/
si->flags += SWP_SCANNING;
- scan_base = offset = si->cluster_next;
+ /*
+ * Use percpu scan base for SSD to reduce lock contention on
+ * cluster and swap cache. For HDD, sequential access is more
+ * important.
+ */
+ if (si->flags & SWP_SOLIDSTATE)
+ scan_base = this_cpu_read(*si->cluster_next_cpu);
+ else
+ scan_base = si->cluster_next;
+ offset = scan_base;
/* SSD algorithm */
if (si->cluster_info) {
- if (scan_swap_map_try_ssd_cluster(si, &offset, &scan_base))
- goto checks;
- else
+ if (!scan_swap_map_try_ssd_cluster(si, &offset, &scan_base))
goto scan;
- }
-
- if (unlikely(!si->cluster_nr--)) {
+ } else if (unlikely(!si->cluster_nr--)) {
if (si->pages - si->inuse_pages < SWAPFILE_CLUSTER) {
si->cluster_nr = SWAPFILE_CLUSTER - 1;
goto checks;
unlock_cluster(ci);
swap_range_alloc(si, offset, 1);
- si->cluster_next = offset + 1;
slots[n_ret++] = swp_entry(si->type, offset);
/* got enough slots or reach max slots? */
if (si->cluster_info) {
if (scan_swap_map_try_ssd_cluster(si, &offset, &scan_base))
goto checks;
- else
- goto done;
- }
- /* non-ssd case */
- ++offset;
-
- /* non-ssd case, still more slots in cluster? */
- if (si->cluster_nr && !si->swap_map[offset]) {
+ } else if (si->cluster_nr && !si->swap_map[++offset]) {
+ /* non-ssd case, still more slots in cluster? */
--si->cluster_nr;
goto checks;
}
+ /*
+ * Even if there's no free clusters available (fragmented),
+ * try to scan a little more quickly with lock held unless we
+ * have scanned too many slots already.
+ */
+ if (!scanned_many) {
+ unsigned long scan_limit;
+
+ if (offset < scan_base)
+ scan_limit = scan_base;
+ else
+ scan_limit = si->highest_bit;
+ for (; offset <= scan_limit && --latency_ration > 0;
+ offset++) {
+ if (!si->swap_map[offset])
+ goto checks;
+ }
+ }
+
done:
+ set_cluster_next(si, offset + 1);
si->flags -= SWP_SCANNING;
return n_ret;
if (unlikely(--latency_ration < 0)) {
cond_resched();
latency_ration = LATENCY_LIMIT;
+ scanned_many = true;
}
}
offset = si->lowest_bit;
if (unlikely(--latency_ration < 0)) {
cond_resched();
latency_ration = LATENCY_LIMIT;
+ scanned_many = true;
}
offset++;
}
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);
}
static unsigned char __swap_entry_free(struct swap_info_struct *p,
- swp_entry_t entry, unsigned char usage)
+ swp_entry_t entry)
{
struct swap_cluster_info *ci;
unsigned long offset = swp_offset(entry);
+ unsigned char usage;
ci = lock_cluster_or_swap_info(p, offset);
- usage = __swap_entry_free_locked(p, offset, usage);
+ usage = __swap_entry_free_locked(p, offset, 1);
unlock_cluster_or_swap_info(p, ci);
if (!usage)
free_swap_slot(entry);
p = _swap_info_get(entry);
if (p)
- __swap_entry_free(p, entry, 1);
+ __swap_entry_free(p, entry);
}
/*
p = _swap_info_get(entry);
if (p) {
- count = __swap_entry_free(p, entry, 1);
+ count = __swap_entry_free(p, entry);
if (count == SWAP_HAS_CACHE &&
!swap_page_trans_huge_swapped(p, entry))
__try_to_reclaim_swap(p, swp_offset(entry),
unsigned long addr, swp_entry_t entry, struct page *page)
{
struct page *swapcache;
- struct mem_cgroup *memcg;
spinlock_t *ptl;
pte_t *pte;
int ret = 1;
if (unlikely(!page))
return -ENOMEM;
- if (mem_cgroup_try_charge(page, vma->vm_mm, GFP_KERNEL,
- &memcg, false)) {
- ret = -ENOMEM;
- goto out_nolock;
- }
-
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
if (unlikely(!pte_same_as_swp(*pte, swp_entry_to_pte(entry)))) {
- mem_cgroup_cancel_charge(page, memcg, false);
ret = 0;
goto out;
}
pte_mkold(mk_pte(page, vma->vm_page_prot)));
if (page == swapcache) {
page_add_anon_rmap(page, vma, addr, false);
- mem_cgroup_commit_charge(page, memcg, true, false);
} else { /* ksm created a completely new copy */
page_add_new_anon_rmap(page, vma, addr, false);
- mem_cgroup_commit_charge(page, memcg, false, false);
lru_cache_add_active_or_unevictable(page, vma);
}
swap_free(entry);
activate_page(page);
out:
pte_unmap_unlock(pte, ptl);
-out_nolock:
if (page != swapcache) {
unlock_page(page);
put_page(page);
pte_unmap(pte);
swap_map = &si->swap_map[offset];
- vmf.vma = vma;
- vmf.address = addr;
- vmf.pmd = pmd;
- page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, &vmf);
+ page = lookup_swap_cache(entry, vma, addr);
+ if (!page) {
+ vmf.vma = vma;
+ vmf.address = addr;
+ vmf.pmd = pmd;
+ page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE,
+ &vmf);
+ }
if (!page) {
if (*swap_map == 0 || *swap_map == SWAP_MAP_BAD)
goto try_next;
struct vm_area_struct *vma;
int ret = 0;
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (vma->anon_vma) {
ret = unuse_vma(vma, type, frontswap,
}
cond_resched();
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return ret;
}
mutex_unlock(&swapon_mutex);
free_percpu(p->percpu_cluster);
p->percpu_cluster = NULL;
+ free_percpu(p->cluster_next_cpu);
+ p->cluster_next_cpu = NULL;
vfree(swap_map);
kvfree(cluster_info);
kvfree(frontswap_map);
struct swap_info_struct *si = v;
struct file *file;
int len;
+ unsigned int bytes, inuse;
if (si == SEQ_START_TOKEN) {
- seq_puts(swap,"Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
+ seq_puts(swap,"Filename\t\t\t\tType\t\tSize\t\tUsed\t\tPriority\n");
return 0;
}
+ bytes = si->pages << (PAGE_SHIFT - 10);
+ inuse = si->inuse_pages << (PAGE_SHIFT - 10);
+
file = si->swap_file;
len = seq_file_path(swap, file, " \t\n\\");
- seq_printf(swap, "%*s%s\t%u\t%u\t%d\n",
+ seq_printf(swap, "%*s%s\t%u\t%s%u\t%s%d\n",
len < 40 ? 40 - len : 1, " ",
S_ISBLK(file_inode(file)->i_mode) ?
"partition" : "file\t",
- si->pages << (PAGE_SHIFT - 10),
- si->inuse_pages << (PAGE_SHIFT - 10),
+ bytes, bytes < 10000000 ? "\t" : "",
+ inuse, inuse < 10000000 ? "\t" : "",
si->prio);
return 0;
}
* write only restriction. Hence zoned block devices are not
* suitable for swapping. Disallow them here.
*/
- if (blk_queue_is_zoned(p->bdev->bd_queue))
+ if (blk_queue_is_zoned(p->bdev->bd_disk->queue))
return -EINVAL;
p->flags |= SWP_BLKDEV;
} else if (S_ISREG(inode->i_mode)) {
unsigned long ci, nr_cluster;
p->flags |= SWP_SOLIDSTATE;
+ p->cluster_next_cpu = alloc_percpu(unsigned int);
+ if (!p->cluster_next_cpu) {
+ error = -ENOMEM;
+ goto bad_swap_unlock_inode;
+ }
/*
* select a random position to start with to help wear leveling
* SSD
*/
- p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
+ for_each_possible_cpu(cpu) {
+ per_cpu(*p->cluster_next_cpu, cpu) =
+ 1 + prandom_u32_max(p->highest_bit);
+ }
nr_cluster = DIV_ROUND_UP(maxpages, SWAPFILE_CLUSTER);
cluster_info = kvcalloc(nr_cluster, sizeof(*cluster_info),
bad_swap:
free_percpu(p->percpu_cluster);
p->percpu_cluster = NULL;
+ free_percpu(p->cluster_next_cpu);
+ p->cluster_next_cpu = NULL;
if (inode && S_ISBLK(inode->i_mode) && p->bdev) {
set_blocksize(p->bdev, p->old_block_size);
blkdev_put(p->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
spin_lock(&si->cont_lock);
offset &= ~PAGE_MASK;
- page = list_entry(head->lru.next, struct page, lru);
+ page = list_next_entry(head, lru);
map = kmap_atomic(page) + offset;
if (count == SWAP_MAP_MAX) /* initial increment from swap_map */
*/
while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) {
kunmap_atomic(map);
- page = list_entry(page->lru.next, struct page, lru);
+ page = list_next_entry(page, lru);
BUG_ON(page == head);
map = kmap_atomic(page) + offset;
}
if (*map == SWAP_CONT_MAX) {
kunmap_atomic(map);
- page = list_entry(page->lru.next, struct page, lru);
+ page = list_next_entry(page, lru);
if (page == head) {
ret = false; /* add count continuation */
goto out;
}
*map += 1;
kunmap_atomic(map);
- page = list_entry(page->lru.prev, struct page, lru);
- while (page != head) {
+ while ((page = list_prev_entry(page, lru)) != head) {
map = kmap_atomic(page) + offset;
*map = COUNT_CONTINUED;
kunmap_atomic(map);
- page = list_entry(page->lru.prev, struct page, lru);
}
ret = true; /* incremented */
BUG_ON(count != COUNT_CONTINUED);
while (*map == COUNT_CONTINUED) {
kunmap_atomic(map);
- page = list_entry(page->lru.next, struct page, lru);
+ page = list_next_entry(page, lru);
BUG_ON(page == head);
map = kmap_atomic(page) + offset;
}
if (*map == 0)
count = 0;
kunmap_atomic(map);
- page = list_entry(page->lru.prev, struct page, lru);
- while (page != head) {
+ while ((page = list_prev_entry(page, lru)) != head) {
map = kmap_atomic(page) + offset;
*map = SWAP_CONT_MAX | count;
count = COUNT_CONTINUED;
kunmap_atomic(map);
- page = list_entry(page->lru.prev, struct page, lru);
}
ret = count == COUNT_CONTINUED;
}
}
#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node,
- gfp_t gfp_mask)
+void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
{
struct swap_info_struct *si, *next;
- if (!(gfp_mask & __GFP_IO) || !memcg)
+ int nid = page_to_nid(page);
+
+ if (!(gfp_mask & __GFP_IO))
return;
if (!blk_cgroup_congested())
return;
spin_lock(&swap_avail_lock);
- plist_for_each_entry_safe(si, next, &swap_avail_heads[node],
- avail_lists[node]) {
+ plist_for_each_entry_safe(si, next, &swap_avail_heads[nid],
+ avail_lists[nid]) {
if (si->bdev) {
- blkcg_schedule_throttle(bdev_get_queue(si->bdev),
- true);
+ blkcg_schedule_throttle(bdev_get_queue(si->bdev), true);
break;
}
}
projects / linux-2.6-microblaze.git / blobdiff