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authorPaul Jackson <pj@sgi.com>2006-01-08 01:01:56 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-08 20:13:44 -0800
commit74cb21553f4bf244185b9bec4c26e4e3169ad55e (patch)
tree3f8f13e8dacc8f0876b01f62765a123ce1722b17 /kernel/cpuset.c
parent909d75a3b77bdd8baa9429bad3b69a654d2954ce (diff)
[PATCH] cpuset: numa_policy_rebind cleanup
Cleanup, reorganize and make more robust the mempolicy.c code to rebind mempolicies relative to the containing cpuset after a tasks memory placement changes. The real motivator for this cleanup patch is to lay more groundwork for the upcoming patch to correctly rebind NUMA mempolicies that are attached to vma's after the containing cpuset memory placement changes. NUMA mempolicies are constrained by the cpuset their task is a member of. When either (1) a task is moved to a different cpuset, or (2) the 'mems' mems_allowed of a cpuset is changed, then the NUMA mempolicies have embedded node numbers (for MPOL_BIND, MPOL_INTERLEAVE and MPOL_PREFERRED) that need to be recalculated, relative to their new cpuset placement. The old code used an unreliable method of determining what was the old mems_allowed constraining the mempolicy. It just looked at the tasks mems_allowed value. This sort of worked with the present code, that just rebinds the -task- mempolicy, and leaves any -vma- mempolicies broken, referring to the old nodes. But in an upcoming patch, the vma mempolicies will be rebound as well. Then the order in which the various task and vma mempolicies are updated will no longer be deterministic, and one can no longer count on the task->mems_allowed holding the old value for as long as needed. It's not even clear if the current code was guaranteed to work reliably for task mempolicies. So I added a mems_allowed field to each mempolicy, stating exactly what mems_allowed the policy is relative to, and updated synchronously and reliably anytime that the mempolicy is rebound. Also removed a useless wrapper routine, numa_policy_rebind(), and had its caller, cpuset_update_task_memory_state(), call directly to the rewritten policy_rebind() routine, and made that rebind routine extern instead of static, and added a "mpol_" prefix to its name, making it mpol_rebind_policy(). Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/cpuset.c')
-rw-r--r--kernel/cpuset.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 0d0dbbd6560a..8f764de3a9e7 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -643,7 +643,7 @@ void cpuset_update_task_memory_state()
tsk->cpuset_mems_generation = cs->mems_generation;
task_unlock(tsk);
up(&callback_sem);
- numa_policy_rebind(&oldmem, &tsk->mems_allowed);
+ mpol_rebind_task(tsk, &tsk->mems_allowed);
if (!nodes_equal(oldmem, tsk->mems_allowed)) {
if (migrate) {
do_migrate_pages(tsk->mm, &oldmem,