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>
This commit is contained in:
Lee Schermerhorn 2008-04-28 02:13:08 -07:00 committed by Linus Torvalds
parent 3b11630063
commit f0be3d32b0
7 changed files with 26 additions and 26 deletions

View File

@ -71,7 +71,7 @@ struct mm_struct;
*
* Freeing policy:
* Mempolicy objects are reference counted. A mempolicy will be freed when
* mpol_free() decrements the reference count to zero.
* mpol_put() decrements the reference count to zero.
*
* Copying policy objects:
* mpol_copy() allocates a new mempolicy and copies the specified mempolicy
@ -98,11 +98,11 @@ struct mempolicy {
* The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
*/
extern void __mpol_free(struct mempolicy *pol);
static inline void mpol_free(struct mempolicy *pol)
extern void __mpol_put(struct mempolicy *pol);
static inline void mpol_put(struct mempolicy *pol)
{
if (pol)
__mpol_free(pol);
__mpol_put(pol);
}
extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
@ -190,7 +190,7 @@ static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
return 1;
}
static inline void mpol_free(struct mempolicy *p)
static inline void mpol_put(struct mempolicy *p)
{
}

View File

@ -967,7 +967,7 @@ NORET_TYPE void do_exit(long code)
proc_exit_connector(tsk);
exit_notify(tsk, group_dead);
#ifdef CONFIG_NUMA
mpol_free(tsk->mempolicy);
mpol_put(tsk->mempolicy);
tsk->mempolicy = NULL;
#endif
#ifdef CONFIG_FUTEX

View File

@ -1374,7 +1374,7 @@ bad_fork_cleanup_security:
security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_free(p->mempolicy);
mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
cgroup_exit(p, cgroup_callbacks_done);

View File

@ -116,7 +116,7 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
break;
}
}
mpol_free(mpol); /* unref if mpol !NULL */
mpol_put(mpol); /* unref if mpol !NULL */
return page;
}

View File

@ -529,7 +529,7 @@ static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
if (!err) {
mpol_get(new);
vma->vm_policy = new;
mpol_free(old);
mpol_put(old);
}
return err;
}
@ -595,7 +595,7 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
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 @@ static long do_mbind(unsigned long start, unsigned long len,
}
up_write(&mm->mmap_sem);
mpol_free(new);
mpol_put(new);
return err;
}
@ -1446,14 +1446,14 @@ struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
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 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
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 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
*/
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 @@ int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
}
/* 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 @@ static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
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 @@ restart:
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 @@ void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy,
/* 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 @@ void mpol_free_shared_policy(struct shared_policy *p)
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 @@ int show_numa_map(struct seq_file *m, void *v)
* 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);

View File

@ -232,7 +232,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
vma->vm_ops->close(vma);
if (vma->vm_file)
fput(vma->vm_file);
mpol_free(vma_policy(vma));
mpol_put(vma_policy(vma));
kmem_cache_free(vm_area_cachep, vma);
return next;
}
@ -626,7 +626,7 @@ again: remove_next = 1 + (end > next->vm_end);
if (file)
fput(file);
mm->map_count--;
mpol_free(vma_policy(next));
mpol_put(vma_policy(next));
kmem_cache_free(vm_area_cachep, next);
/*
* In mprotect's case 6 (see comments on vma_merge),
@ -1182,7 +1182,7 @@ munmap_back:
if (file && vma_merge(mm, prev, addr, vma->vm_end,
vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
mpol_free(vma_policy(vma));
mpol_put(vma_policy(vma));
kmem_cache_free(vm_area_cachep, vma);
fput(file);
} else {

View File

@ -1196,7 +1196,7 @@ static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp,
pvma.vm_ops = NULL;
pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
page = swapin_readahead(entry, gfp, &pvma, 0);
mpol_free(pvma.vm_policy);
mpol_put(pvma.vm_policy);
return page;
}
@ -1212,7 +1212,7 @@ static struct page *shmem_alloc_page(gfp_t gfp,
pvma.vm_ops = NULL;
pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
page = alloc_page_vma(gfp, &pvma, 0);
mpol_free(pvma.vm_policy);
mpol_put(pvma.vm_policy);
return page;
}
#else /* !CONFIG_NUMA */