Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
From:   Gregory Price <gourry.memverge@gmail.com>
To:     linux-mm@kvack.org
Cc:     linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        arnd@arndb.de, tglx@linutronix.de, luto@kernel.org,
        mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, mhocko@kernel.org, tj@kernel.org,
        ying.huang@intel.com, Gregory Price <gregory.price@memverge.com>
Subject: [RFC PATCH 08/11] mm/mempolicy: export replace_mempolicy for use by procfs
Date:   Wed, 22 Nov 2023 16:11:57 -0500
Message-Id: <20231122211200.31620-9-gregory.price@memverge.com>
In-Reply-To: <20231122211200.31620-1-gregory.price@memverge.com>
References: <20231122211200.31620-1-gregory.price@memverge.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

We will be adding a /proc/pid/mempolicy entry for use in swapping
the mempolicy of a process at runtime.  Export replace_mempolicy
so that this can be used by that interface.

Signed-off-by: Gregory Price <gregory.price@memverge.com>
---
 include/linux/mempolicy.h | 9 +++++++++
 mm/mempolicy.c            | 5 ++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 931b118336f4..b951e96a53ce 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -177,6 +177,8 @@ static inline bool mpol_is_preferred_many(struct mempolicy *pol)
 
 extern bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone);
 
+extern long replace_mempolicy(struct task_struct *task, struct mempolicy *new,
+			      nodemask_t *nodes);
 #else
 
 struct mempolicy {};
@@ -297,5 +299,12 @@ static inline bool mpol_is_preferred_many(struct mempolicy *pol)
 	return  false;
 }
 
+static inline long replace_mempolicy(struct task_struct *task,
+				     struct mempolicy *new,
+				     nodemask_t *nodes)
+{
+	return -ENODEV;
+}
+
 #endif /* CONFIG_NUMA */
 #endif
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index fb295ade8ad7..e0c9127571dd 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -815,9 +815,8 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
 }
 
 /* Attempt to replace mempolicy, release the old one if successful */
-static long replace_mempolicy(struct task_struct *task,
-			      struct mempolicy *new,
-			      nodemask_t *nodes)
+long replace_mempolicy(struct task_struct *task, struct mempolicy *new,
+		       nodemask_t *nodes)
 {
 	struct mempolicy *old = NULL;
 	NODEMASK_SCRATCH(scratch);
-- 
2.39.1