From a67b44a1256861c3d415b48f50c4cafa61c32ba0 Mon Sep 17 00:00:00 2001 From: Greg Thelen Date: Mon, 24 May 2010 14:32:33 -0700 Subject: [PATCH] mm: consider the entire user address space during node migration Use mm->task_size instead of TASK_SIZE to ensure that the entire user address space is migrated. mm->task_size is independent of the calling task context. TASK SIZE may be dependant on the address space size of the calling process. Usage of TASK_SIZE can lead to partial address space migration if the calling process was 32 bit and the migrating process was 64 bit. Here is the test script used on 64 system with a 32 bit echo process: mount -t cgroup none /cgroup -o cpuset cd /cgroup mkdir 0 echo 1 > 0/cpuset.cpus echo 0 > 0/cpuset.mems echo 1 > 0/cpuset.memory_migrate mkdir 1 echo 1 > 1/cpuset.cpus echo 1 > 1/cpuset.mems echo 1 > 1/cpuset.memory_migrate echo $$ > 0/tasks 64_bit_process & pid=$! echo $pid > 1/tasks # This does not migrate all process pages without # this patch. If 64 bit echo is used or this patch is # applied, then the full address space of $pid is # migrated. To check memory migration, I watched: grep MemUsed /sys/devices/system/node/node*/meminfo Signed-off-by: Greg Thelen Acked-by: Christoph Lameter Reviewed-by: KOSAKI Motohiro Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 721b2b338032d..75751012c5520 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -928,7 +928,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, nodes_clear(nmask); node_set(source, nmask); - check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nmask, + check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, flags | MPOL_MF_DISCONTIG_OK, &pagelist); if (!list_empty(&pagelist)) -- 2.39.5