Group short-lived and reclaimable kernel allocations

This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 6 insertions, 4 deletions

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 06ab3c10b1b8..a6be78c05dce 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -1710,7 +1710,7 @@ static int journal_init_journal_head_cache(void)
         journal_head_cache = kmem_cache_create("journal_head",
                                 sizeof(struct journal_head),
                                 0,              /* offset */
-                                0,              /* flags */
+                                SLAB_TEMPORARY, /* flags */
                                 NULL);          /* ctor */
         retval = 0;
         if (journal_head_cache == 0) {
@@ -2006,7 +2006,7 @@ static int __init journal_init_handle_cache(void)
         jbd_handle_cache = kmem_cache_create("journal_handle",
                                 sizeof(handle_t),
                                 0,              /* offset */
-                                0,              /* flags */
+                                SLAB_TEMPORARY, /* flags */
                                 NULL);          /* ctor */
         if (jbd_handle_cache == NULL) {
                 printk(KERN_EMERG "JBD: failed to create handle cache\n");
diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c
index 62e13c8db132..ad2eacf570c6 100644
--- a/fs/jbd/revoke.c
+++ b/fs/jbd/revoke.c
@@ -170,13 +170,15 @@ int __init journal_init_revoke_caches(void)
 {
         revoke_record_cache = kmem_cache_create("revoke_record",
                                            sizeof(struct jbd_revoke_record_s),
-                                           0, SLAB_HWCACHE_ALIGN, NULL);
+                                           0,
+                                           SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
+                                           NULL);
         if (revoke_record_cache == 0)
                 return -ENOMEM;
 
         revoke_table_cache = kmem_cache_create("revoke_table",
                                            sizeof(struct jbd_revoke_table_s),
-                                           0, 0, NULL);
+                                           0, SLAB_TEMPORARY, NULL);
         if (revoke_table_cache == 0) {
                 kmem_cache_destroy(revoke_record_cache);
                 revoke_record_cache = NULL;