memcgroup: fix hang with shmem/tmpfs

[linux-2.6-omap-h63xx.git] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index 0f246c44a5744ec5aac0930c7896923e96bcb215..85bed948fafc8aecb22daf1f68023b91080a30f4 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -912,9 +912,13 @@ found:
        error = 1;
        if (!inode)
                goto out;
-       error = radix_tree_preload(GFP_KERNEL);
+       /* Precharge page while we can wait, compensate afterwards */
+       error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
        if (error)
                goto out;
+       error = radix_tree_preload(GFP_KERNEL);
+       if (error)
+               goto uncharge;
        error = 1;
 
        spin_lock(&info->lock);
@@ -947,6 +951,8 @@ found:
                shmem_swp_unmap(ptr);
        spin_unlock(&info->lock);
        radix_tree_preload_end();
+uncharge:
+       mem_cgroup_uncharge_page(page);
 out:
        unlock_page(page);
        page_cache_release(page);
@@ -1308,6 +1314,13 @@ repeat:
                        spin_unlock(&info->lock);
                        unlock_page(swappage);
                        page_cache_release(swappage);
+                       if (error == -ENOMEM) {
+                               /* allow reclaim from this memory cgroup */
+                               error = mem_cgroup_cache_charge(NULL,
+                                       current->mm, gfp & ~__GFP_HIGHMEM);
+                               if (error)
+                                       goto failed;
+                       }
                        goto repeat;
                }
        } else if (sgp == SGP_READ && !filepage) {
@@ -1353,6 +1366,17 @@ repeat:
                                goto failed;
                        }
 
+                       /* Precharge page while we can wait, compensate after */
+                       error = mem_cgroup_cache_charge(filepage, current->mm,
+                                                       gfp & ~__GFP_HIGHMEM);
+                       if (error) {
+                               page_cache_release(filepage);
+                               shmem_unacct_blocks(info->flags, 1);
+                               shmem_free_blocks(inode, 1);
+                               filepage = NULL;
+                               goto failed;
+                       }
+
                        spin_lock(&info->lock);
                        entry = shmem_swp_alloc(info, idx, sgp);
                        if (IS_ERR(entry))
@@ -1364,6 +1388,7 @@ repeat:
                        if (error || swap.val || 0 != add_to_page_cache_lru(
                                        filepage, mapping, idx, GFP_NOWAIT)) {
                                spin_unlock(&info->lock);
+                               mem_cgroup_uncharge_page(filepage);
                                page_cache_release(filepage);
                                shmem_unacct_blocks(info->flags, 1);
                                shmem_free_blocks(inode, 1);
@@ -1372,6 +1397,7 @@ repeat:
                                        goto failed;
                                goto repeat;
                        }
+                       mem_cgroup_uncharge_page(filepage);
                        info->flags |= SHMEM_PAGEIN;
                }