The patch titled
Subject: mempolicy: alloc_pages_mpol() for NUMA policy without vma: fix
has been added to the -mm mm-unstable branch. Its filename is
mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mempolicy: alloc_pages_mpol() for NUMA policy without vma: fix
Date: Tue, 24 Oct 2023 09:09:39 -0700 (PDT)
mm-unstable commit 48a7bd12d57f ("mempolicy: alloc_pages_mpol() for NUMA
policy without vma") ended read_swap_cache_async() supporting NULL vma -
okay; but missed the NULL mpol being passed to __read_swap_cache_async()
by zswap_writeback_entry() - oops!
Since its other callers all give good mpol, add get_task_policy(current)
there in mm/zswap.c, to produce the same good-enough behaviour as before
(and task policy, acted on in current task, does not require the refcount
to be dup'ed).
But if that policy is (quite reasonably) MPOL_INTERLEAVE, then ilx must be
NO_INTERLEAVE_INDEX rather than 0, to provide the same distribution as
before: move that definition from mempolicy.c to mempolicy.h.
Link: https://lkml.kernel.org/r/ea419956-4751-0102-21f7-9c93cb957892@xxxxxxxxxx
Fixes: 48a7bd12d57f ("mempolicy: alloc_pages_mpol() for NUMA policy without vma")
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Reported-by: Domenico Cerasuolo <mimmocerasuolo@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-mm/74e34633-6060-f5e3-aee-7040d43f2e93@xxxxxxxxxx/T/#mf08c877d1884fc7867f9e328cdf02257ff3b3ae9
Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Tejun heo <tj@xxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mempolicy.h | 7 +++++++
mm/mempolicy.c | 2 --
mm/zswap.c | 7 +++++--
3 files changed, 12 insertions(+), 4 deletions(-)
--- a/include/linux/mempolicy.h~mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix
+++ a/include/linux/mempolicy.h
@@ -17,6 +17,8 @@
struct mm_struct;
+#define NO_INTERLEAVE_INDEX (-1UL) /* use task il_prev for interleaving */
+
#ifdef CONFIG_NUMA
/*
@@ -179,6 +181,11 @@ extern bool apply_policy_zone(struct mem
struct mempolicy {};
+static inline struct mempolicy *get_task_policy(struct task_struct *p)
+{
+ return NULL;
+}
+
static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
{
return true;
--- a/mm/mempolicy.c~mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix
+++ a/mm/mempolicy.c
@@ -114,8 +114,6 @@
#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */
#define MPOL_MF_WRLOCK (MPOL_MF_INTERNAL << 2) /* Write-lock walked vmas */
-#define NO_INTERLEAVE_INDEX (-1UL)
-
static struct kmem_cache *policy_cache;
static struct kmem_cache *sn_cache;
--- a/mm/zswap.c~mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix
+++ a/mm/zswap.c
@@ -24,6 +24,7 @@
#include <linux/swap.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
+#include <linux/mempolicy.h>
#include <linux/mempool.h>
#include <linux/zpool.h>
#include <crypto/acompress.h>
@@ -1057,6 +1058,7 @@ static int zswap_writeback_entry(struct
{
swp_entry_t swpentry = entry->swpentry;
struct page *page;
+ struct mempolicy *mpol;
struct scatterlist input, output;
struct crypto_acomp_ctx *acomp_ctx;
struct zpool *pool = zswap_find_zpool(entry);
@@ -1075,8 +1077,9 @@ static int zswap_writeback_entry(struct
}
/* try to allocate swap cache page */
- page = __read_swap_cache_async(swpentry, GFP_KERNEL, NULL, 0,
- &page_was_allocated);
+ mpol = get_task_policy(current);
+ page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
+ NO_INTERLEAVE_INDEX, &page_was_allocated);
if (!page) {
ret = -ENOMEM;
goto fail;
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
hugetlbfs-drop-shared-numa-mempolicy-pretence.patch
kernfs-drop-shared-numa-mempolicy-hooks.patch
mempolicy-fix-migrate_pages2-syscall-return-nr_failed.patch
mempolicy-trivia-delete-those-ancient-pr_debugs.patch
mempolicy-trivia-slightly-more-consistent-naming.patch
mempolicy-trivia-use-pgoff_t-in-shared-mempolicy-tree.patch
mempolicy-mpol_shared_policy_init-without-pseudo-vma.patch
mempolicy-remove-confusing-mpol_mf_lazy-dead-code.patch
mm-add-page_rmappable_folio-wrapper.patch
mempolicy-alloc_pages_mpol-for-numa-policy-without-vma.patch
mempolicy-alloc_pages_mpol-for-numa-policy-without-vma-fix.patch
mempolicy-mmap_lock-is-not-needed-while-migrating-folios.patch
mempolicy-migration-attempt-to-match-interleave-nodes.patch
mempolicy-migration-attempt-to-match-interleave-nodes-fix.patch
ext4-add-__gfp_nowarn-to-gfp_nowait-in-readahead.patch
mm-mlock-avoid-folio_within_range-on-ksm-pages.patch
