From f3b39d47ebc51416fc3b690a32dfe030a2035e67 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Tue, 16 Jun 2009 15:31:46 -0700 Subject: [PATCH] cpusets: restructure the function cpuset_update_task_memory_state() The kernel still allocates the page caches on old node after modifying its cpuset's mems when 'memory_spread_page' was set, or it didn't spread the page cache evenly over all the nodes that faulting task is allowed to usr after memory_spread_page was set. it is caused by the old mem_allowed and flags of the task, the current kernel doesn't updates them unless some function invokes cpuset_update_task_memory_state(), it is too late sometimes.We must update the mem_allowed and the flags of the tasks in time. Slab has the same problem. The following patches fix this bug by updating tasks' mem_allowed and spread flag after its cpuset's mems or spread flag is changed. This patch: Extract a function from cpuset_update_task_memory_state(). It will be used later for update tasks' page/slab spread flags after its cpuset's flag is set Signed-off-by: Miao Xie Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Christoph Lameter Cc: Paul Menage Cc: Nick Piggin Cc: Yasunori Goto Cc: Pekka Enberg Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index d5a7e17474ee..66b24d9b6638 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -331,6 +331,24 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) BUG_ON(!nodes_intersects(*pmask, node_states[N_HIGH_MEMORY])); } +/* + * update task's spread flag if cpuset's page/slab spread flag is set + * + * Called with callback_mutex/cgroup_mutex held + */ +static void cpuset_update_task_spread_flag(struct cpuset *cs, + struct task_struct *tsk) +{ + if (is_spread_page(cs)) + tsk->flags |= PF_SPREAD_PAGE; + else + tsk->flags &= ~PF_SPREAD_PAGE; + if (is_spread_slab(cs)) + tsk->flags |= PF_SPREAD_SLAB; + else + tsk->flags &= ~PF_SPREAD_SLAB; +} + /** * cpuset_update_task_memory_state - update task memory placement * @@ -388,14 +406,7 @@ void cpuset_update_task_memory_state(void) cs = task_cs(tsk); /* Maybe changed when task not locked */ guarantee_online_mems(cs, &tsk->mems_allowed); tsk->cpuset_mems_generation = cs->mems_generation; - if (is_spread_page(cs)) - tsk->flags |= PF_SPREAD_PAGE; - else - tsk->flags &= ~PF_SPREAD_PAGE; - if (is_spread_slab(cs)) - tsk->flags |= PF_SPREAD_SLAB; - else - tsk->flags &= ~PF_SPREAD_SLAB; + cpuset_update_task_spread_flag(cs, tsk); task_unlock(tsk); mutex_unlock(&callback_mutex); mpol_rebind_task(tsk, &tsk->mems_allowed); -- 2.30.2