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Commit f3b39d47 authored by Miao Xie's avatar Miao Xie Committed by Linus Torvalds
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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: default avatarMiao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent dcf975d5

kernel/cpuset.c

+19 −8
Original line number Original line Diff line number Diff line
@@ -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]));

	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

 * 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 */

		cs = task_cs(tsk); /* Maybe changed when task not locked */

		guarantee_online_mems(cs, &tsk->mems_allowed);

		guarantee_online_mems(cs, &tsk->mems_allowed);

		tsk->cpuset_mems_generation = cs->mems_generation;

		tsk->cpuset_mems_generation = cs->mems_generation;

		if (is_spread_page(cs))

		cpuset_update_task_spread_flag(cs, tsk);

			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;

		task_unlock(tsk);

		task_unlock(tsk);

		mutex_unlock(&callback_mutex);

		mutex_unlock(&callback_mutex);

		mpol_rebind_task(tsk, &tsk->mems_allowed);

		mpol_rebind_task(tsk, &tsk->mems_allowed);