[merged mm-hotfixes-stable] maple_tree-add-gfp_kernel-to-allocations-in-mas_expected_entries.patch removed from -mm tree

[merged mm-hotfixes-stable] maple_tree-add-gfp_kernel-to-allocations-in-mas_expected_entries.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()
has been removed from the -mm tree.  Its filename was
     maple_tree-add-gfp_kernel-to-allocations-in-mas_expected_entries.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Subject: maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()
Date: Thu, 12 Oct 2023 11:52:33 -0400

Users complained about OOM errors during fork without triggering
compaction.  This can be fixed by modifying the flags used in
mas_expected_entries() so that the compaction will be triggered in low
memory situations.  Since mas_expected_entries() is only used during fork,
the extra argument does not need to be passed through.

Additionally, the two test_maple_tree test cases and one benchmark test
were altered to use the correct locking type so that allocations would not
trigger sleeping and thus fail.  Testing was completed with lockdep atomic
sleep detection.

The additional locking change requires rwsem support additions to the
tools/ directory through the use of pthreads pthread_rwlock_t.  With this
change test_maple_tree works in userspace, as a module, and in-kernel.

Users may notice that the system gave up early on attempting to start new
processes instead of attempting to reclaim memory.

Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4
Link: https://lkml.kernel.org/r/20231012155233.2272446-1-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <jason.sim@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c            |    2 -
 lib/test_maple_tree.c       |   35 ++++++++++++++++++++---------
 tools/include/linux/rwsem.h |   40 ++++++++++++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 12 deletions(-)

--- a/lib/maple_tree.c~maple_tree-add-gfp_kernel-to-allocations-in-mas_expected_entries
+++ a/lib/maple_tree.c
@@ -5627,7 +5627,7 @@ int mas_expected_entries(struct ma_state
 	/* Internal nodes */
 	nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
 	/* Add working room for split (2 nodes) + new parents */
-	mas_node_count(mas, nr_nodes + 3);
+	mas_node_count_gfp(mas, nr_nodes + 3, GFP_KERNEL);
 
 	/* Detect if allocations run out */
 	mas->mas_flags |= MA_STATE_PREALLOC;
--- a/lib/test_maple_tree.c~maple_tree-add-gfp_kernel-to-allocations-in-mas_expected_entries
+++ a/lib/test_maple_tree.c
@@ -9,6 +9,7 @@
 
 #include <linux/maple_tree.h>
 #include <linux/module.h>
+#include <linux/rwsem.h>
 
 #define MTREE_ALLOC_MAX 0x2000000000000Ul
 #define CONFIG_MAPLE_SEARCH
@@ -1841,17 +1842,21 @@ static noinline void __init check_forkin
 	void *val;
 	MA_STATE(mas, mt, 0, 0);
 	MA_STATE(newmas, mt, 0, 0);
+	struct rw_semaphore newmt_lock;
+
+	init_rwsem(&newmt_lock);
 
 	for (i = 0; i <= nr_entries; i++)
 		mtree_store_range(mt, i*10, i*10 + 5,
 				  xa_mk_value(i), GFP_KERNEL);
 
 	mt_set_non_kernel(99999);
-	mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE);
+	mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN);
+	mt_set_external_lock(&newmt, &newmt_lock);
 	newmas.tree = &newmt;
 	mas_reset(&newmas);
 	mas_reset(&mas);
-	mas_lock(&newmas);
+	down_write(&newmt_lock);
 	mas.index = 0;
 	mas.last = 0;
 	if (mas_expected_entries(&newmas, nr_entries)) {
@@ -1866,10 +1871,10 @@ static noinline void __init check_forkin
 	}
 	rcu_read_unlock();
 	mas_destroy(&newmas);
-	mas_unlock(&newmas);
 	mt_validate(&newmt);
 	mt_set_non_kernel(0);
-	mtree_destroy(&newmt);
+	__mt_destroy(&newmt);
+	up_write(&newmt_lock);
 }
 
 static noinline void __init check_iteration(struct maple_tree *mt)
@@ -1980,6 +1985,10 @@ static noinline void __init bench_forkin
 	void *val;
 	MA_STATE(mas, mt, 0, 0);
 	MA_STATE(newmas, mt, 0, 0);
+	struct rw_semaphore newmt_lock;
+
+	init_rwsem(&newmt_lock);
+	mt_set_external_lock(&newmt, &newmt_lock);
 
 	for (i = 0; i <= nr_entries; i++)
 		mtree_store_range(mt, i*10, i*10 + 5,
@@ -1994,7 +2003,7 @@ static noinline void __init bench_forkin
 		mas.index = 0;
 		mas.last = 0;
 		rcu_read_lock();
-		mas_lock(&newmas);
+		down_write(&newmt_lock);
 		if (mas_expected_entries(&newmas, nr_entries)) {
 			printk("OOM!");
 			BUG_ON(1);
@@ -2005,11 +2014,11 @@ static noinline void __init bench_forkin
 			mas_store(&newmas, val);
 		}
 		mas_destroy(&newmas);
-		mas_unlock(&newmas);
 		rcu_read_unlock();
 		mt_validate(&newmt);
 		mt_set_non_kernel(0);
-		mtree_destroy(&newmt);
+		__mt_destroy(&newmt);
+		up_write(&newmt_lock);
 	}
 }
 #endif
@@ -2616,6 +2625,10 @@ static noinline void __init check_dup_ga
 	void *tmp;
 	MA_STATE(mas, mt, 0, 0);
 	MA_STATE(newmas, &newmt, 0, 0);
+	struct rw_semaphore newmt_lock;
+
+	init_rwsem(&newmt_lock);
+	mt_set_external_lock(&newmt, &newmt_lock);
 
 	if (!zero_start)
 		i = 1;
@@ -2625,9 +2638,9 @@ static noinline void __init check_dup_ga
 		mtree_store_range(mt, i*10, (i+1)*10 - gap,
 				  xa_mk_value(i), GFP_KERNEL);
 
-	mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE);
+	mt_init_flags(&newmt, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN);
 	mt_set_non_kernel(99999);
-	mas_lock(&newmas);
+	down_write(&newmt_lock);
 	ret = mas_expected_entries(&newmas, nr_entries);
 	mt_set_non_kernel(0);
 	MT_BUG_ON(mt, ret != 0);
@@ -2640,9 +2653,9 @@ static noinline void __init check_dup_ga
 	}
 	rcu_read_unlock();
 	mas_destroy(&newmas);
-	mas_unlock(&newmas);
 
-	mtree_destroy(&newmt);
+	__mt_destroy(&newmt);
+	up_write(&newmt_lock);
 }
 
 /* Duplicate many sizes of trees.  Mainly to test expected entry values */
--- /dev/null
+++ a/tools/include/linux/rwsem.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef _TOOLS__RWSEM_H
+#define _TOOLS__RWSEM_H
+
+#include <pthread.h>
+
+struct rw_semaphore {
+	pthread_rwlock_t lock;
+};
+
+static inline int init_rwsem(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_init(&sem->lock, NULL);
+}
+
+static inline int exit_rwsem(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_destroy(&sem->lock);
+}
+
+static inline int down_read(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_rdlock(&sem->lock);
+}
+
+static inline int up_read(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_unlock(&sem->lock);
+}
+
+static inline int down_write(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_wrlock(&sem->lock);
+}
+
+static inline int up_write(struct rw_semaphore *sem)
+{
+	return pthread_rwlock_unlock(&sem->lock);
+}
+#endif /* _TOOLS_RWSEM_H */
_

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

mmap-add-clarifying-comment-to-vma_merge-code.patch
radix-tree-test-suite-fix-allocation-calculation-in-kmem_cache_alloc_bulk.patch