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authorMel Gorman <mgorman@techsingularity.net>2017-11-15 17:37:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-15 18:21:06 -0800
commitc7df8ad2910e965a6241b6d8f52fd122e26b0315 (patch)
tree19c00fc5eda9394aec1a1b9d2c2e7f8d2dee9616 /lib/radix-tree.c
parent9cca35d42eb61b69e108a17215756c46173a5e6f (diff)
mm, truncate: do not check mapping for every page being truncated
During truncation, the mapping has already been checked for shmem and dax so it's known that workingset_update_node is required. This patch avoids the checks on mapping for each page being truncated. In all other cases, a lookup helper is used to determine if workingset_update_node() needs to be called. The one danger is that the API is slightly harder to use as calling workingset_update_node directly without checking for dax or shmem mappings could lead to surprises. However, the API rarely needs to be used and hopefully the comment is enough to give people the hint. sparsetruncate (tiny) 4.14.0-rc4 4.14.0-rc4 oneirq-v1r1 pickhelper-v1r1 Min Time 141.00 ( 0.00%) 140.00 ( 0.71%) 1st-qrtle Time 142.00 ( 0.00%) 141.00 ( 0.70%) 2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%) 3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%) Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%) Max-95% Time 147.00 ( 0.00%) 145.00 ( 1.36%) Max-99% Time 195.00 ( 0.00%) 191.00 ( 2.05%) Max Time 230.00 ( 0.00%) 205.00 ( 10.87%) Amean Time 144.37 ( 0.00%) 143.82 ( 0.38%) Stddev Time 10.44 ( 0.00%) 9.00 ( 13.74%) Coeff Time 7.23 ( 0.00%) 6.26 ( 13.41%) Best99%Amean Time 143.72 ( 0.00%) 143.34 ( 0.26%) Best95%Amean Time 142.37 ( 0.00%) 142.00 ( 0.26%) Best90%Amean Time 142.19 ( 0.00%) 141.85 ( 0.24%) Best75%Amean Time 141.92 ( 0.00%) 141.58 ( 0.24%) Best50%Amean Time 141.69 ( 0.00%) 141.31 ( 0.27%) Best25%Amean Time 141.38 ( 0.00%) 140.97 ( 0.29%) As you'd expect, the gain is marginal but it can be detected. The differences in bonnie are all within the noise which is not surprising given the impact on the microbenchmark. radix_tree_update_node_t is a callback for some radix operations that optionally passes in a private field. The only user of the callback is workingset_update_node and as it no longer requires a mapping, the private field is removed. Link: http://lkml.kernel.org/r/20171018075952.10627-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/radix-tree.c')
-rw-r--r--lib/radix-tree.c30
1 files changed, 13 insertions, 17 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8b1feca1230a..c8d55565fafa 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -677,8 +677,7 @@ out:
* @root radix tree root
*/
static inline bool radix_tree_shrink(struct radix_tree_root *root,
- radix_tree_update_node_t update_node,
- void *private)
+ radix_tree_update_node_t update_node)
{
bool shrunk = false;
@@ -739,7 +738,7 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root,
if (!radix_tree_is_internal_node(child)) {
node->slots[0] = (void __rcu *)RADIX_TREE_RETRY;
if (update_node)
- update_node(node, private);
+ update_node(node);
}
WARN_ON_ONCE(!list_empty(&node->private_list));
@@ -752,7 +751,7 @@ static inline bool radix_tree_shrink(struct radix_tree_root *root,
static bool delete_node(struct radix_tree_root *root,
struct radix_tree_node *node,
- radix_tree_update_node_t update_node, void *private)
+ radix_tree_update_node_t update_node)
{
bool deleted = false;
@@ -762,8 +761,8 @@ static bool delete_node(struct radix_tree_root *root,
if (node->count) {
if (node_to_entry(node) ==
rcu_dereference_raw(root->rnode))
- deleted |= radix_tree_shrink(root, update_node,
- private);
+ deleted |= radix_tree_shrink(root,
+ update_node);
return deleted;
}
@@ -1173,7 +1172,6 @@ static int calculate_count(struct radix_tree_root *root,
* @slot: pointer to slot in @node
* @item: new item to store in the slot.
* @update_node: callback for changing leaf nodes
- * @private: private data to pass to @update_node
*
* For use with __radix_tree_lookup(). Caller must hold tree write locked
* across slot lookup and replacement.
@@ -1181,7 +1179,7 @@ static int calculate_count(struct radix_tree_root *root,
void __radix_tree_replace(struct radix_tree_root *root,
struct radix_tree_node *node,
void __rcu **slot, void *item,
- radix_tree_update_node_t update_node, void *private)
+ radix_tree_update_node_t update_node)
{
void *old = rcu_dereference_raw(*slot);
int exceptional = !!radix_tree_exceptional_entry(item) -
@@ -1201,9 +1199,9 @@ void __radix_tree_replace(struct radix_tree_root *root,
return;
if (update_node)
- update_node(node, private);
+ update_node(node);
- delete_node(root, node, update_node, private);
+ delete_node(root, node, update_node);
}
/**
@@ -1225,7 +1223,7 @@ void __radix_tree_replace(struct radix_tree_root *root,
void radix_tree_replace_slot(struct radix_tree_root *root,
void __rcu **slot, void *item)
{
- __radix_tree_replace(root, NULL, slot, item, NULL, NULL);
+ __radix_tree_replace(root, NULL, slot, item, NULL);
}
EXPORT_SYMBOL(radix_tree_replace_slot);
@@ -1242,7 +1240,7 @@ void radix_tree_iter_replace(struct radix_tree_root *root,
const struct radix_tree_iter *iter,
void __rcu **slot, void *item)
{
- __radix_tree_replace(root, iter->node, slot, item, NULL, NULL);
+ __radix_tree_replace(root, iter->node, slot, item, NULL);
}
#ifdef CONFIG_RADIX_TREE_MULTIORDER
@@ -1972,7 +1970,6 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
* @root: radix tree root
* @node: node containing @index
* @update_node: callback for changing leaf nodes
- * @private: private data to pass to @update_node
*
* After clearing the slot at @index in @node from radix tree
* rooted at @root, call this function to attempt freeing the
@@ -1980,10 +1977,9 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
*/
void __radix_tree_delete_node(struct radix_tree_root *root,
struct radix_tree_node *node,
- radix_tree_update_node_t update_node,
- void *private)
+ radix_tree_update_node_t update_node)
{
- delete_node(root, node, update_node, private);
+ delete_node(root, node, update_node);
}
static bool __radix_tree_delete(struct radix_tree_root *root,
@@ -2001,7 +1997,7 @@ static bool __radix_tree_delete(struct radix_tree_root *root,
node_tag_clear(root, node, tag, offset);
replace_slot(slot, NULL, node, -1, exceptional);
- return node && delete_node(root, node, NULL, NULL);
+ return node && delete_node(root, node, NULL);
}
/**