lkml.org 
[lkml]   [2018]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v9 34/61] mm: Convert truncate to XArray
Date
From: Matthew Wilcox <mawilcox@microsoft.com>

This is essentially xa_cmpxchg() with the locking handled above us,
and it doesn't have to handle replacing a NULL entry.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
mm/truncate.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/mm/truncate.c b/mm/truncate.c
index ed778555c9f3..45d68e90b703 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -33,15 +33,12 @@
static inline void __clear_shadow_entry(struct address_space *mapping,
pgoff_t index, void *entry)
{
- struct radix_tree_node *node;
- void **slot;
+ XA_STATE(xas, &mapping->i_pages, index);

- if (!__radix_tree_lookup(&mapping->i_pages, index, &node, &slot))
+ xas_set_update(&xas, workingset_update_node);
+ if (xas_load(&xas) != entry)
return;
- if (*slot != entry)
- return;
- __radix_tree_replace(&mapping->i_pages, node, slot, NULL,
- workingset_update_node);
+ xas_store(&xas, NULL);
mapping->nrexceptional--;
}

@@ -738,10 +735,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
index++;
}
/*
- * For DAX we invalidate page tables after invalidating radix tree. We
+ * For DAX we invalidate page tables after invalidating page cache. We
* could invalidate page tables while invalidating each entry however
* that would be expensive. And doing range unmapping before doesn't
- * work as we have no cheap way to find whether radix tree entry didn't
+ * work as we have no cheap way to find whether page cache entry didn't
* get remapped later.
*/
if (dax_mapping(mapping)) {
--
2.16.1
\
 
 \ /
  Last update: 2018-03-13 14:43    [W:0.254 / U:21.620 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site