on 2009-5-4 11:06 Lee Schermerhorn wrote:
> Against: 2.6.20-rc3-mmotm-090428-1631
>
> Since cpusetmm-update-tasks-mems_allowed-in-time.patch removed the call outs
> to cpuset_update_task_memory_state(), tasks in the top cpuset don't get their
> mems_allowed updated to just nodes with memory. cpuset_init()initializes
> the top cpuset's mems_allowed with nodes_setall() and
> cpuset_init_current_mems_allowed() and kernel_init() initialize the kernel
> initialization tasks' mems_allowed to all possible nodes. Tasks in the top
> cpuset that inherit the init task's mems_allowed without modification will
> have all possible nodes set. This can be seen by examining the Mems_allowed
> field in /proc/<pid>/status in such a task.
>
> "numactl --interleave=all" also initializes the interleave node mask to all
> ones, depending on the masking with mems_allowed to eliminate non-existent
> nodes and nodes without memory. As this was not happening, the interleave
> policy was attempting to dereference non-existent nodes.
>
> This patch modifies the nodes_setall() calls in two cpuset init functions and
> the initialization of task #1's mems_allowed to use node_states[N_HIGH_MEMORY].
> This mask has been initialized to contain only existing nodes with memory by
> the time the respective init functions are called.
You forget to modify the cpuset_attach(). This function will initialize the
mems_allowed of the task which is being moved into the top cpuset by node_possible_map.
Beside that, if you use node_states[N_HIGH_MEMORY] to initialize the mems_allowed
of the tasks in the top cpuset, you must update it when adding a node with memory into
the system. So you also must modify cpuset_track_online_nodes().
Thanks
Miao
>
> This fixes the bogus pointer deref [Nat Consumption fault on ia64] reported
> in:
>
> [BUG] 2.6.30-rc3-mmotm-090428-1814 -- bogus pointer deref
>
> [The time--1814--was incorrect in that subject line, but the date was correct.]
>
> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
>
> init/main.c | 4 ++--
> kernel/cpuset.c | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> Index: linux-2.6.30-rc3-mmotm-090428-1631/kernel/cpuset.c
> ===================================================================
> --- linux-2.6.30-rc3-mmotm-090428-1631.orig/kernel/cpuset.c 2009-05-03 18:26:24.000000000 -0400
> +++ linux-2.6.30-rc3-mmotm-090428-1631/kernel/cpuset.c 2009-05-03 20:46:04.000000000 -0400
> @@ -1846,7 +1846,7 @@ int __init cpuset_init(void)
> BUG();
>
> cpumask_setall(top_cpuset.cpus_allowed);
> - nodes_setall(top_cpuset.mems_allowed);
> + top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
>
> fmeter_init(&top_cpuset.fmeter);
> set_bit(CS_SCHED_LOAD_BALANCE, &top_cpuset.flags);
> @@ -2118,7 +2118,7 @@ void cpuset_cpus_allowed_locked(struct t
>
> void cpuset_init_current_mems_allowed(void)
> {
> - nodes_setall(current->mems_allowed);
> + current->mems_allowed = node_states[N_HIGH_MEMORY];
> }
>
> /**
> Index: linux-2.6.30-rc3-mmotm-090428-1631/init/main.c
> ===================================================================
> --- linux-2.6.30-rc3-mmotm-090428-1631.orig/init/main.c 2009-05-03 20:46:04.000000000 -0400
> +++ linux-2.6.30-rc3-mmotm-090428-1631/init/main.c 2009-05-03 20:54:03.000000000 -0400
> @@ -849,9 +849,9 @@ static int __init kernel_init(void * unu
> lock_kernel();
>
> /*
> - * init can allocate pages on any node
> + * init can allocate pages on any node with memory
> */
> - set_mems_allowed(node_possible_map);
> + set_mems_allowed(node_states[N_HIGH_MEMORY]);
> /*
> * init can run on any cpu.
> */
>
>
>
>
>
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