mempolicy: rename mpol_free to mpol_put
This is a change that was requested some time ago by Mel Gorman. Makes sense
to me, so here it is.
Note: I retain the name "mpol_free_shared_policy()" because it actually does
free the shared_policy, which is NOT a reference counted object. However, ...
The mempolicy object[s] referenced by the shared_policy are reference counted,
so mpol_put() is used to release the reference held by the shared_policy. The
mempolicy might not be freed at this time, because some task attached to the
shared object associated with the shared policy may be in the process of
allocating a page based on the mempolicy. In that case, the task performing
the allocation will hold a reference on the mempolicy, obtained via
mpol_shared_policy_lookup(). The mempolicy will be freed when all tasks
holding such a reference have called mpol_put() for the mempolicy.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index c1b9077..ce2c5b6 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -529,7 +529,7 @@
if (!err) {
mpol_get(new);
vma->vm_policy = new;
- mpol_free(old);
+ mpol_put(old);
}
return err;
}
@@ -595,7 +595,7 @@
new = mpol_new(mode, flags, nodes);
if (IS_ERR(new))
return PTR_ERR(new);
- mpol_free(current->mempolicy);
+ mpol_put(current->mempolicy);
current->mempolicy = new;
mpol_set_task_struct_flag();
if (new && new->policy == MPOL_INTERLEAVE &&
@@ -948,7 +948,7 @@
}
up_write(&mm->mmap_sem);
- mpol_free(new);
+ mpol_put(new);
return err;
}
@@ -1446,14 +1446,14 @@
nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
if (unlikely(pol != &default_policy &&
pol != current->mempolicy))
- __mpol_free(pol); /* finished with pol */
+ __mpol_put(pol); /* finished with pol */
return node_zonelist(nid, gfp_flags);
}
zl = zonelist_policy(GFP_HIGHUSER, pol);
if (unlikely(pol != &default_policy && pol != current->mempolicy)) {
if (pol->policy != MPOL_BIND)
- __mpol_free(pol); /* finished with pol */
+ __mpol_put(pol); /* finished with pol */
else
*mpol = pol; /* unref needed after allocation */
}
@@ -1512,7 +1512,7 @@
nid = interleave_nid(pol, vma, addr, PAGE_SHIFT);
if (unlikely(pol != &default_policy &&
pol != current->mempolicy))
- __mpol_free(pol); /* finished with pol */
+ __mpol_put(pol); /* finished with pol */
return alloc_page_interleave(gfp, 0, nid);
}
zl = zonelist_policy(gfp, pol);
@@ -1522,7 +1522,7 @@
*/
struct page *page = __alloc_pages_nodemask(gfp, 0,
zl, nodemask_policy(gfp, pol));
- __mpol_free(pol);
+ __mpol_put(pol);
return page;
}
/*
@@ -1624,7 +1624,7 @@
}
/* Slow path of a mpol destructor. */
-void __mpol_free(struct mempolicy *p)
+void __mpol_put(struct mempolicy *p)
{
if (!atomic_dec_and_test(&p->refcnt))
return;
@@ -1720,7 +1720,7 @@
{
pr_debug("deleting %lx-l%lx\n", n->start, n->end);
rb_erase(&n->nd, &sp->root);
- mpol_free(n->policy);
+ mpol_put(n->policy);
kmem_cache_free(sn_cache, n);
}
@@ -1780,7 +1780,7 @@
sp_insert(sp, new);
spin_unlock(&sp->lock);
if (new2) {
- mpol_free(new2->policy);
+ mpol_put(new2->policy);
kmem_cache_free(sn_cache, new2);
}
return 0;
@@ -1805,7 +1805,7 @@
/* Policy covers entire file */
pvma.vm_end = TASK_SIZE;
mpol_set_shared_policy(info, &pvma, newpol);
- mpol_free(newpol);
+ mpol_put(newpol);
}
}
}
@@ -1848,7 +1848,7 @@
n = rb_entry(next, struct sp_node, nd);
next = rb_next(&n->nd);
rb_erase(&n->nd, &p->root);
- mpol_free(n->policy);
+ mpol_put(n->policy);
kmem_cache_free(sn_cache, n);
}
spin_unlock(&p->lock);
@@ -2068,7 +2068,7 @@
* unref shared or other task's mempolicy
*/
if (pol != &default_policy && pol != current->mempolicy)
- __mpol_free(pol);
+ __mpol_put(pol);
seq_printf(m, "%08lx %s", vma->vm_start, buffer);