[RFC PATCH 1/3] mm/mempolicy: refactor do_set_mempolicy for code re-use

Gregory Price
2023-09-14T23:55:13Z

Refactors do_set_mempolicy into swap_mempolicy and do_set_mempolicy
so that swap_mempolicy can be re-used with set_mempolicy2.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
mm/mempolicy.c | 44 +++++++++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 42b5567e3773..f49337f6f300 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -855,28 +855,21 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
return vma_replace_policy(vma, new_pol);
}

-/* Set the process memory policy */
-static long do_set_mempolicy(unsigned short mode, unsigned short flags,
- nodemask_t *nodes)
+/* Swap in a new mempolicy, release the old one if successful */
+static long swap_mempolicy(struct mempolicy *new,
+ nodemask_t *nodes)
{
- struct mempolicy *new, *old;
- NODEMASK_SCRATCH(scratch);
+ struct mempolicy *old = NULL;
int ret;
+ NODEMASK_SCRATCH(scratch);

if (!scratch)
return -ENOMEM;

- new = mpol_new(mode, flags, nodes);
- if (IS_ERR(new)) {
- ret = PTR_ERR(new);
- goto out;
- }
-
task_lock(current);
ret = mpol_set_nodemask(new, nodes, scratch);
if (ret) {
task_unlock(current);
- mpol_put(new);
goto out;
}

@@ -884,14 +877,35 @@ static long do_set_mempolicy(unsigned short mode, unsigned short flags,
current->mempolicy = new;
if (new && new->mode == MPOL_INTERLEAVE)
current->il_prev = MAX_NUMNODES-1;
- task_unlock(current);
- mpol_put(old);
- ret = 0;
out:
+ task_unlock(current);
+ if (old)
+ mpol_put(old);
+
NODEMASK_SCRATCH_FREE(scratch);
return ret;
}

+/* Set the process memory policy */
+static long do_set_mempolicy(unsigned short mode, unsigned short flags,
+ nodemask_t *nodes)
+{
+ struct mempolicy *new;
+ int ret;
+
+ new = mpol_new(mode, flags, nodes);
+ if (IS_ERR(new)) {
+ ret = PTR_ERR(new);
+ goto out;
+ }
+
+ ret = swap_mempolicy(new, nodes);
+ if (ret)
+ mpol_put(new);
+out:
+ return ret;
+}
+
/*
* Return nodemask for policy for get_mempolicy() query
*
--
2.39.1