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| author | Jack Steiner <steiner@sgi.com> | 2010-05-26 14:42:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-27 09:12:44 -0700 |
| commit | 0ac0c0d0f837c499afd02a802f9cf52d3027fa3b (patch) | |
| tree | c20a7306d4b727722556af1aa5565855686aee07 /include/linux/nodemask.h | |
| parent | 6adef3ebe570bcde67fd6c16101451ddde5712b5 (diff) | |
| download | lwn-0ac0c0d0f837c499afd02a802f9cf52d3027fa3b.tar.gz lwn-0ac0c0d0f837c499afd02a802f9cf52d3027fa3b.zip | |
cpusets: randomize node rotor used in cpuset_mem_spread_node()
Some workloads that create a large number of small files tend to assign
too many pages to node 0 (multi-node systems). Part of the reason is that
the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at
node 0 for newly created tasks.
This patch changes the rotor to be initialized to a random node number of
the cpuset.
[akpm@linux-foundation.org: fix layout]
[Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/nodemask.h')
| -rw-r--r-- | include/linux/nodemask.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h index dba35e413371..8a8f1d09c133 100644 --- a/include/linux/nodemask.h +++ b/include/linux/nodemask.h @@ -66,6 +66,8 @@ * int num_online_nodes() Number of online Nodes * int num_possible_nodes() Number of all possible Nodes * + * int node_random(mask) Random node with set bit in mask + * * int node_online(node) Is some node online? * int node_possible(node) Is some node possible? * @@ -430,6 +432,10 @@ static inline void node_set_offline(int nid) node_clear_state(nid, N_ONLINE); nr_online_nodes = num_node_state(N_ONLINE); } + +#define node_random(mask) __node_random(&(mask)) +extern int __node_random(const nodemask_t *maskp); + #else static inline int node_state(int node, enum node_states state) @@ -460,6 +466,8 @@ static inline int num_node_state(enum node_states state) #define node_set_online(node) node_set_state((node), N_ONLINE) #define node_set_offline(node) node_clear_state((node), N_ONLINE) + +static inline int node_random(const nodemask_t mask) { return 0; } #endif #define node_online_map node_states[N_ONLINE] |