Re: [PATCH -mmotm] fix more cpuset breakage

From: Andrew Morton
Date: Thu Jan 29 2009 - 04:45:06 EST


On Wed, 28 Jan 2009 19:24:24 -0800 Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote:

> From: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
>
> Not everyone uses cpusets, so fix the b0rked build (part 2):
>
> kernel/kthread.c:243: error: 'struct task_struct' has no member named 'mems_allowed'
>
> Signed-off-by: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
> ---
> kernel/kthread.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> --- mmotm-2009-0128-1742.orig/kernel/kthread.c
> +++ mmotm-2009-0128-1742/kernel/kthread.c
> @@ -240,7 +240,9 @@ int kthreadd(void *unused)
> set_user_nice(tsk, KTHREAD_NICE_LEVEL);
> set_cpus_allowed_ptr(tsk, CPU_MASK_ALL_PTR);
>
> +#ifdef CONFIG_CPUSETS
> current->mems_allowed = node_possible_map;
> +#endif
> current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG;
>
> for (;;) {

OK, enough ifdefs. I did this:

--- a/include/linux/cpuset.h~cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set-fix-2
+++ a/include/linux/cpuset.h
@@ -79,6 +79,11 @@ extern void rebuild_sched_domains(void);

extern void cpuset_print_task_mems_allowed(struct task_struct *p);

+static inline void set_mems_allowed(nodemask_t nodemask)
+{
+ current->mems_allowed = nodemask;
+}
+
#else /* !CONFIG_CPUSETS */

static inline int cpuset_init(void) { return 0; }
@@ -163,6 +168,10 @@ static inline void cpuset_print_task_mem
{
}

+static inline void set_mems_allowed(nodemask_t nodemask)
+{
+}
+
#endif /* !CONFIG_CPUSETS */

#endif /* _LINUX_CPUSET_H */
--- a/init/main.c~cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set-fix-2
+++ a/init/main.c
@@ -873,7 +873,7 @@ static int __init kernel_init(void * unu
*/
init_pid_ns.child_reaper = current;

- current->mems_allowed = node_possible_map;
+ set_mems_allowed(node_possible_map);

cad_pid = task_pid(current);

--- a/kernel/kthread.c~cpuset-fix-allocating-page-cache-slab-object-on-the-unallowed-node-when-memory-spread-is-set-fix-2
+++ a/kernel/kthread.c
@@ -13,6 +13,8 @@
#include <linux/file.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/cpuset.h>
+
#include <trace/sched.h>

#define KTHREAD_NICE_LEVEL (-5)
@@ -242,7 +244,7 @@ int kthreadd(void *unused)
set_user_nice(tsk, KTHREAD_NICE_LEVEL);
set_cpus_allowed_ptr(tsk, CPU_MASK_ALL_PTR);

- current->mems_allowed = node_possible_map;
+ set_mems_allowed(node_possible_map);
current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG;

for (;;) {
_


Also, I think we're still waiting for someone to tell us why
kernel_init() (at least) needed that chantge?

And why did kthreadd need changing, come to that?

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