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authorHugh Dickins <hughd@google.com>2011-08-03 16:21:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-08-03 14:25:24 -1000
commitaa3b189551ad8e5cc1d9c663735c131650238278 (patch)
treec789ab5c7f890a6065811d8bba15a784caf9e859 /mm/memcontrol.c
parent54af60421822bb9cb664dd5cd7aac46c01ccfcf8 (diff)
downloadlinux-aa3b189551ad8e5cc1d9c663735c131650238278.tar.bz2
tmpfs: convert mem_cgroup shmem to radix-swap
Remove mem_cgroup_shmem_charge_fallback(): it was only required when we had to move swappage to filecache with GFP_NOWAIT. Remove the GFP_NOWAIT special case from mem_cgroup_cache_charge(), by moving its call out from shmem_add_to_page_cache() to two of thats three callers. But leave it doing mem_cgroup_uncharge_cache_page() on error: although asymmetrical, it's easier for all 3 callers to handle. These two changes would also be appropriate if anyone were to start using shmem_read_mapping_page_gfp() with GFP_NOWAIT. Remove mem_cgroup_get_shmem_target(): mc_handle_file_pte() can test radix_tree_exceptional_entry() to get what it needs for itself. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
-rw-r--r--mm/memcontrol.c66
1 files changed, 9 insertions, 57 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5f84d2351ddb..f4ec4e7ca4cd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -35,7 +35,6 @@
#include <linux/limits.h>
#include <linux/mutex.h>
#include <linux/rbtree.h>
-#include <linux/shmem_fs.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/swapops.h>
@@ -2873,30 +2872,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
return 0;
if (PageCompound(page))
return 0;
- /*
- * Corner case handling. This is called from add_to_page_cache()
- * in usual. But some FS (shmem) precharges this page before calling it
- * and call add_to_page_cache() with GFP_NOWAIT.
- *
- * For GFP_NOWAIT case, the page may be pre-charged before calling
- * add_to_page_cache(). (See shmem.c) check it here and avoid to call
- * charge twice. (It works but has to pay a bit larger cost.)
- * And when the page is SwapCache, it should take swap information
- * into account. This is under lock_page() now.
- */
- if (!(gfp_mask & __GFP_WAIT)) {
- struct page_cgroup *pc;
-
- pc = lookup_page_cgroup(page);
- if (!pc)
- return 0;
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc)) {
- unlock_page_cgroup(pc);
- return 0;
- }
- unlock_page_cgroup(pc);
- }
if (unlikely(!mm))
mm = &init_mm;
@@ -3486,31 +3461,6 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
cgroup_release_and_wakeup_rmdir(&mem->css);
}
-/*
- * A call to try to shrink memory usage on charge failure at shmem's swapin.
- * Calling hierarchical_reclaim is not enough because we should update
- * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
- * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
- * not from the memcg which this page would be charged to.
- * try_charge_swapin does all of these works properly.
- */
-int mem_cgroup_shmem_charge_fallback(struct page *page,
- struct mm_struct *mm,
- gfp_t gfp_mask)
-{
- struct mem_cgroup *mem;
- int ret;
-
- if (mem_cgroup_disabled())
- return 0;
-
- ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
- if (!ret)
- mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
-
- return ret;
-}
-
#ifdef CONFIG_DEBUG_VM
static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
{
@@ -5330,15 +5280,17 @@ static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
pgoff = pte_to_pgoff(ptent);
/* page is moved even if it's not RSS of this task(page-faulted). */
- if (!mapping_cap_swap_backed(mapping)) { /* normal file */
- page = find_get_page(mapping, pgoff);
- } else { /* shmem/tmpfs file. we should take account of swap too. */
- swp_entry_t ent;
- mem_cgroup_get_shmem_target(inode, pgoff, &page, &ent);
+ page = find_get_page(mapping, pgoff);
+
+#ifdef CONFIG_SWAP
+ /* shmem/tmpfs may report page out on swap: account for that too. */
+ if (radix_tree_exceptional_entry(page)) {
+ swp_entry_t swap = radix_to_swp_entry(page);
if (do_swap_account)
- entry->val = ent.val;
+ *entry = swap;
+ page = find_get_page(&swapper_space, swap.val);
}
-
+#endif
return page;
}