[PATCH] CPUSET related breakage of sys_mbind

[PATCH] CPUSET related breakage of sys_mbind

[Bob Picco]

current->mems_allowed is defined for CONFIG_CPUSETS. This broke !CPUSETS
build. I compiled and linked tested both variants.

Signed-off-by: Bob Picco <bob.picco@hp.com>

 include/linux/cpuset.h |    6 ++++++
 mm/mempolicy.c         |    2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

Index: linux-2.6.20-rc4-mm1/mm/mempolicy.c
===================================================================
--- linux-2.6.20-rc4-mm1.orig/mm/mempolicy.c	2007-01-15 09:21:58.000000000 -0500
+++ linux-2.6.20-rc4-mm1/mm/mempolicy.c	2007-01-15 17:51:15.000000000 -0500
@@ -882,9 +882,9 @@ asmlinkage long sys_mbind(unsigned long 
 	int err;
 
 	err = get_nodes(&nodes, nmask, maxnode);
-	nodes_and(nodes, nodes, current->mems_allowed);
 	if (err)
 		return err;
+	cpuset_nodes_allowed(&nodes);
 	return do_mbind(start, len, mode, &nodes, flags);
 }
 
Index: linux-2.6.20-rc4-mm1/include/linux/cpuset.h
===================================================================
--- linux-2.6.20-rc4-mm1.orig/include/linux/cpuset.h	2007-01-15 09:21:32.000000000 -0500
+++ linux-2.6.20-rc4-mm1/include/linux/cpuset.h	2007-01-15 14:01:30.000000000 -0500
@@ -75,6 +75,11 @@ static inline int cpuset_do_slab_mem_spr
 
 extern void cpuset_track_online_nodes(void);
 
+static inline void cpuset_nodes_allowed(nodemask_t *nodes)
+{
+	nodes_and(*nodes, *nodes, current->mems_allowed);
+}
+
 #else /* !CONFIG_CPUSETS */
 
 static inline int cpuset_init_early(void) { return 0; }
@@ -145,6 +150,7 @@ static inline int cpuset_do_slab_mem_spr
 }
 
 static inline void cpuset_track_online_nodes(void) {}
+static inline void cpuset_nodes_allowed(nodemask_t *nodes) {}
 
 #endif /* !CONFIG_CPUSETS */
 

Re: [PATCH] CPUSET related breakage of sys_mbind

[Paul Jackson]

You're right about this problemI think that Christoph Lameter
(added to cc list) is working on a fix for this.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401

Re: [PATCH] CPUSET related breakage of sys_mbind

[Christoph Lameter]

On Mon, 15 Jan 2007, Paul Jackson wrote:

> You're right about this problemI think that Christoph Lameter
> (added to cc list) is working on a fix for this.

Cpusets is your thing so I think you could fix this the right way. There 
are already two different patches fixing this. Just make it the way that 
it fits cpusets.

Re: [PATCH] CPUSET related breakage of sys_mbind

[Paul Jackson]

Christoph wrote:
> Cpusets is your thing so I think you could fix this the right way.

But wasn't it your patch that broke ...

Actually, I'd have blessed Bob Picco's patch, as it's done the right
way, with a cpuset_* macro hook, defined twice in cpuset.h, with and
without CONFIG_CPUSET, where the without case compiles to a no-op.
This is the same way as is used for the couple dozen other cpuset
kernel hooks.

But I thought you were already signed up for this one, so I didn't want
to trample on your efforts.

And, perhaps more important, I understood you had some other patches in
the works that have cpuset hooks.  I'm thinking it would be a good idea
to learn how these hooks are done, so we don't have to come around here
again.

How about this ... you take another look at Bob's patch.  If it's ok by
you too, then we can both bless it, and that should do it.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401

Re: [PATCH] CPUSET related breakage of sys_mbind

[Paul Jackson]

Patch looks good - thanks, Bob.

Signed-off-by: Paul Jackson <pj@sgi.com>

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401

Re: [PATCH] CPUSET related breakage of sys_mbind

[Christoph Lameter]

On Mon, 15 Jan 2007, Paul Jackson wrote:

> Patch looks good - thanks, Bob.
> 
> Signed-off-by: Paul Jackson <pj@sgi.com>

Looks good to me too.

Signed-off-by: Christoph Lameter <clameter@sgi.com>