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-rw-r--r--block/blk-ioc.c2
-rw-r--r--fs/fscache/page.c2
-rw-r--r--include/linux/radix-tree.h1
-rw-r--r--lib/radix-tree.c41
-rw-r--r--mm/filemap.c2
-rw-r--r--mm/shmem.c2
-rw-r--r--mm/swap_state.c4
7 files changed, 46 insertions, 8 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 4464c82..46cd7bd 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -367,7 +367,7 @@ struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
if (!icq)
return NULL;
- if (radix_tree_preload(gfp_mask) < 0) {
+ if (radix_tree_maybe_preload(gfp_mask) < 0) {
kmem_cache_free(et->icq_cache, icq);
return NULL;
}
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 8702b73..73899c1 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -913,7 +913,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,
(1 << FSCACHE_OP_WAITING) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
- ret = radix_tree_preload(gfp & ~__GFP_HIGHMEM);
+ ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM);
if (ret < 0)
goto nomem_free;
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index ffc444c..4039407 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -231,6 +231,7 @@ unsigned long radix_tree_next_hole(struct radix_tree_root *root,
unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
int radix_tree_preload(gfp_t gfp_mask);
+int radix_tree_maybe_preload(gfp_t gfp_mask);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,
unsigned long index, unsigned int tag);
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index e796429..7811ed3 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -32,6 +32,7 @@
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/rcupdate.h>
+#include <linux/hardirq.h> /* in_interrupt() */
#ifdef __KERNEL__
@@ -207,7 +208,12 @@ radix_tree_node_alloc(struct radix_tree_root *root)
struct radix_tree_node *ret = NULL;
gfp_t gfp_mask = root_gfp_mask(root);
- if (!(gfp_mask & __GFP_WAIT)) {
+ /*
+ * Preload code isn't irq safe and it doesn't make sence to use
+ * preloading in the interrupt anyway as all the allocations have to
+ * be atomic. So just do normal allocation when in interrupt.
+ */
+ if (!(gfp_mask & __GFP_WAIT) && !in_interrupt()) {
struct radix_tree_preload *rtp;
/*
@@ -264,7 +270,7 @@ radix_tree_node_free(struct radix_tree_node *node)
* To make use of this facility, the radix tree must be initialised without
* __GFP_WAIT being passed to INIT_RADIX_TREE().
*/
-int radix_tree_preload(gfp_t gfp_mask)
+static int __radix_tree_preload(gfp_t gfp_mask)
{
struct radix_tree_preload *rtp;
struct radix_tree_node *node;
@@ -288,9 +294,40 @@ int radix_tree_preload(gfp_t gfp_mask)
out:
return ret;
}
+
+/*
+ * Load up this CPU's radix_tree_node buffer with sufficient objects to
+ * ensure that the addition of a single element in the tree cannot fail. On
+ * success, return zero, with preemption disabled. On error, return -ENOMEM
+ * with preemption not disabled.
+ *
+ * To make use of this facility, the radix tree must be initialised without
+ * __GFP_WAIT being passed to INIT_RADIX_TREE().
+ */
+int radix_tree_preload(gfp_t gfp_mask)
+{
+ /* Warn on non-sensical use... */
+ WARN_ON_ONCE(!(gfp_mask & __GFP_WAIT));
+ return __radix_tree_preload(gfp_mask);
+}
EXPORT_SYMBOL(radix_tree_preload);
/*
+ * The same as above function, except we don't guarantee preloading happens.
+ * We do it, if we decide it helps. On success, return zero with preemption
+ * disabled. On error, return -ENOMEM with preemption not disabled.
+ */
+int radix_tree_maybe_preload(gfp_t gfp_mask)
+{
+ if (gfp_mask & __GFP_WAIT)
+ return __radix_tree_preload(gfp_mask);
+ /* Preloading doesn't help anything with this gfp mask, skip it */
+ preempt_disable();
+ return 0;
+}
+EXPORT_SYMBOL(radix_tree_maybe_preload);
+
+/*
* Return the maximum key which can be store into a
* radix tree with height HEIGHT.
*/
diff --git a/mm/filemap.c b/mm/filemap.c
index 731a2c2..e607728 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -469,7 +469,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
if (error)
goto out;
- error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
+ error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM);
if (error == 0) {
page_cache_get(page);
page->mapping = mapping;
diff --git a/mm/shmem.c b/mm/shmem.c
index 5261498..a1b8bf4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1205,7 +1205,7 @@ repeat:
gfp & GFP_RECLAIM_MASK);
if (error)
goto decused;
- error = radix_tree_preload(gfp & GFP_RECLAIM_MASK);
+ error = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK);
if (!error) {
error = shmem_add_to_page_cache(page, mapping, index,
gfp, NULL);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index f24ab0d..e6f15f8 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -122,7 +122,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
{
int error;
- error = radix_tree_preload(gfp_mask);
+ error = radix_tree_maybe_preload(gfp_mask);
if (!error) {
error = __add_to_swap_cache(page, entry);
radix_tree_preload_end();
@@ -328,7 +328,7 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
/*
* call radix_tree_preload() while we can wait.
*/
- err = radix_tree_preload(gfp_mask & GFP_KERNEL);
+ err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL);
if (err)
break;
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