[PATCH] Align VM locks

From: Mark Hemment (markhe@veritas.com)
Date: Thu Aug 16 2001 - 12:41:08 EST


Hi,

  The patch below ensures the pagecache_lock and pagemap_lru_lock aren't
sharing an L1 cacheline with anyone else - espically each other!

Mark

diff -ur -X dontdiff linux-2.4.9-pre4/mm/filemap.c L1-2.4.9-pre4/mm/filemap.c
--- linux-2.4.9-pre4/mm/filemap.c Thu Aug 16 15:57:51 2001
+++ L1-2.4.9-pre4/mm/filemap.c Thu Aug 16 18:28:24 2001
@@ -45,12 +45,12 @@
 unsigned int page_hash_bits;
 struct page **page_hash_table;

-spinlock_t pagecache_lock = SPIN_LOCK_UNLOCKED;
+spinlock_t __cacheline_aligned pagecache_lock = SPIN_LOCK_UNLOCKED;
 /*
  * NOTE: to avoid deadlocking you must never acquire the pagecache_lock with
  * the pagemap_lru_lock held.
  */
-spinlock_t pagemap_lru_lock = SPIN_LOCK_UNLOCKED;
+spinlock_t __cacheline_aligned pagemap_lru_lock = SPIN_LOCK_UNLOCKED;

 #define CLUSTER_PAGES (1 << page_cluster)
 #define CLUSTER_OFFSET(x) (((x) >> page_cluster) << page_cluster)

-
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This archive was generated by hypermail 2b29 : Thu Aug 23 2001 - 21:00:16 EST