[ANNOUNCE] v5.10.4-rt21v5.10.4-rt21-patches

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

5 files changed, 5 insertions, 525 deletions

diff --git a/patches/0001-z3fold-simplify-freeing-slots.patch b/patches/0001-z3fold-simplify-freeing-slots.patch
deleted file mode 100644
index f1e9b9151afc..000000000000
--- a/patches/0001-z3fold-simplify-freeing-slots.patch
+++ /dev/null
@@ -1,177 +0,0 @@
-From: Vitaly Wool <vitaly.wool@konsulko.com>
-Date: Mon, 14 Dec 2020 19:12:30 -0800
-Subject: [PATCH 1/3] z3fold: simplify freeing slots
-
-Patch series "z3fold: stability / rt fixes".
-
-Address z3fold stability issues under stress load, primarily in the
-reclaim and free aspects.  Besides, it fixes the locking problems that
-were only seen in real-time kernel configuration.
-
-This patch (of 3):
-
-There used to be two places in the code where slots could be freed, namely
-when freeing the last allocated handle from the slots and when releasing
-the z3fold header these slots aree linked to.  The logic to decide on
-whether to free certain slots was complicated and error prone in both
-functions and it led to failures in RT case.
-
-To fix that, make free_handle() the single point of freeing slots.
-
-Link: https://lkml.kernel.org/r/20201209145151.18994-1-vitaly.wool@konsulko.com
-Link: https://lkml.kernel.org/r/20201209145151.18994-2-vitaly.wool@konsulko.com
-Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
-Tested-by: Mike Galbraith <efault@gmx.de>
-Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
-Cc: <stable@vger.kernel.org>
-Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
----
- mm/z3fold.c |   55 +++++++++++++------------------------------------------
- 1 file changed, 13 insertions(+), 42 deletions(-)
-
---- a/mm/z3fold.c
-+++ b/mm/z3fold.c
-@@ -90,7 +90,7 @@ struct z3fold_buddy_slots {
- 	 * be enough slots to hold all possible variants
- 	 */
- 	unsigned long slot[BUDDY_MASK + 1];
--	unsigned long pool; /* back link + flags */
-+	unsigned long pool; /* back link */
- 	rwlock_t lock;
- };
- #define HANDLE_FLAG_MASK	(0x03)
-@@ -182,13 +182,6 @@ enum z3fold_page_flags {
- };
- 
- /*
-- * handle flags, go under HANDLE_FLAG_MASK
-- */
--enum z3fold_handle_flags {
--	HANDLES_ORPHANED = 0,
--};
--
--/*
-  * Forward declarations
-  */
- static struct z3fold_header *__z3fold_alloc(struct z3fold_pool *, size_t, bool);
-@@ -303,10 +296,9 @@ static inline void put_z3fold_header(str
- 		z3fold_page_unlock(zhdr);
- }
- 
--static inline void free_handle(unsigned long handle)
-+static inline void free_handle(unsigned long handle, struct z3fold_header *zhdr)
- {
- 	struct z3fold_buddy_slots *slots;
--	struct z3fold_header *zhdr;
- 	int i;
- 	bool is_free;
- 
-@@ -316,22 +308,13 @@ static inline void free_handle(unsigned
- 	if (WARN_ON(*(unsigned long *)handle == 0))
- 		return;
- 
--	zhdr = handle_to_z3fold_header(handle);
- 	slots = handle_to_slots(handle);
- 	write_lock(&slots->lock);
- 	*(unsigned long *)handle = 0;
--	if (zhdr->slots == slots) {
--		write_unlock(&slots->lock);
--		return; /* simple case, nothing else to do */
--	}
-+	if (zhdr->slots != slots)
-+		zhdr->foreign_handles--;
- 
--	/* we are freeing a foreign handle if we are here */
--	zhdr->foreign_handles--;
- 	is_free = true;
--	if (!test_bit(HANDLES_ORPHANED, &slots->pool)) {
--		write_unlock(&slots->lock);
--		return;
--	}
- 	for (i = 0; i <= BUDDY_MASK; i++) {
- 		if (slots->slot[i]) {
- 			is_free = false;
-@@ -343,6 +326,8 @@ static inline void free_handle(unsigned
- 	if (is_free) {
- 		struct z3fold_pool *pool = slots_to_pool(slots);
- 
-+		if (zhdr->slots == slots)
-+			zhdr->slots = NULL;
- 		kmem_cache_free(pool->c_handle, slots);
- 	}
- }
-@@ -525,8 +510,6 @@ static void __release_z3fold_page(struct
- {
- 	struct page *page = virt_to_page(zhdr);
- 	struct z3fold_pool *pool = zhdr_to_pool(zhdr);
--	bool is_free = true;
--	int i;
- 
- 	WARN_ON(!list_empty(&zhdr->buddy));
- 	set_bit(PAGE_STALE, &page->private);
-@@ -536,21 +519,6 @@ static void __release_z3fold_page(struct
- 		list_del_init(&page->lru);
- 	spin_unlock(&pool->lock);
- 
--	/* If there are no foreign handles, free the handles array */
--	read_lock(&zhdr->slots->lock);
--	for (i = 0; i <= BUDDY_MASK; i++) {
--		if (zhdr->slots->slot[i]) {
--			is_free = false;
--			break;
--		}
--	}
--	if (!is_free)
--		set_bit(HANDLES_ORPHANED, &zhdr->slots->pool);
--	read_unlock(&zhdr->slots->lock);
--
--	if (is_free)
--		kmem_cache_free(pool->c_handle, zhdr->slots);
--
- 	if (locked)
- 		z3fold_page_unlock(zhdr);
- 
-@@ -973,6 +941,9 @@ static inline struct z3fold_header *__z3
- 		}
- 	}
- 
-+	if (zhdr && !zhdr->slots)
-+		zhdr->slots = alloc_slots(pool,
-+					can_sleep ? GFP_NOIO : GFP_ATOMIC);
- 	return zhdr;
- }
- 
-@@ -1270,7 +1241,7 @@ static void z3fold_free(struct z3fold_po
- 	}
- 
- 	if (!page_claimed)
--		free_handle(handle);
-+		free_handle(handle, zhdr);
- 	if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) {
- 		atomic64_dec(&pool->pages_nr);
- 		return;
-@@ -1429,19 +1400,19 @@ static int z3fold_reclaim_page(struct z3
- 			ret = pool->ops->evict(pool, middle_handle);
- 			if (ret)
- 				goto next;
--			free_handle(middle_handle);
-+			free_handle(middle_handle, zhdr);
- 		}
- 		if (first_handle) {
- 			ret = pool->ops->evict(pool, first_handle);
- 			if (ret)
- 				goto next;
--			free_handle(first_handle);
-+			free_handle(first_handle, zhdr);
- 		}
- 		if (last_handle) {
- 			ret = pool->ops->evict(pool, last_handle);
- 			if (ret)
- 				goto next;
--			free_handle(last_handle);
-+			free_handle(last_handle, zhdr);
- 		}
- next:
- 		if (test_bit(PAGE_HEADLESS, &page->private)) {
diff --git a/patches/0002-z3fold-stricter-locking-and-more-careful-reclaim.patch b/patches/0002-z3fold-stricter-locking-and-more-careful-reclaim.patch
deleted file mode 100644
index 00c342c24938..000000000000
--- a/patches/0002-z3fold-stricter-locking-and-more-careful-reclaim.patch
+++ /dev/null
@@ -1,341 +0,0 @@
-From: Vitaly Wool <vitaly.wool@konsulko.com>
-Date: Mon, 14 Dec 2020 19:12:33 -0800
-Subject: [PATCH 2/3] z3fold: stricter locking and more careful reclaim
-
-Use temporary slots in reclaim function to avoid possible race when
-freeing those.
-
-While at it, make sure we check CLAIMED flag under page lock in the
-reclaim function to make sure we are not racing with z3fold_alloc().
-
-Link: https://lkml.kernel.org/r/20201209145151.18994-4-vitaly.wool@konsulko.com
-Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
-Cc: <stable@vger.kernel.org>
-Cc: Mike Galbraith <efault@gmx.de>
-Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
-Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
----
- mm/z3fold.c |  143 +++++++++++++++++++++++++++++++++++-------------------------
- 1 file changed, 85 insertions(+), 58 deletions(-)
-
---- a/mm/z3fold.c
-+++ b/mm/z3fold.c
-@@ -182,6 +182,13 @@ enum z3fold_page_flags {
- };
- 
- /*
-+ * handle flags, go under HANDLE_FLAG_MASK
-+ */
-+enum z3fold_handle_flags {
-+	HANDLES_NOFREE = 0,
-+};
-+
-+/*
-  * Forward declarations
-  */
- static struct z3fold_header *__z3fold_alloc(struct z3fold_pool *, size_t, bool);
-@@ -311,6 +318,12 @@ static inline void free_handle(unsigned
- 	slots = handle_to_slots(handle);
- 	write_lock(&slots->lock);
- 	*(unsigned long *)handle = 0;
-+
-+	if (test_bit(HANDLES_NOFREE, &slots->pool)) {
-+		write_unlock(&slots->lock);
-+		return; /* simple case, nothing else to do */
-+	}
-+
- 	if (zhdr->slots != slots)
- 		zhdr->foreign_handles--;
- 
-@@ -621,6 +634,28 @@ static inline void add_to_unbuddied(stru
- 	}
- }
- 
-+static inline enum buddy get_free_buddy(struct z3fold_header *zhdr, int chunks)
-+{
-+	enum buddy bud = HEADLESS;
-+
-+	if (zhdr->middle_chunks) {
-+		if (!zhdr->first_chunks &&
-+		    chunks <= zhdr->start_middle - ZHDR_CHUNKS)
-+			bud = FIRST;
-+		else if (!zhdr->last_chunks)
-+			bud = LAST;
-+	} else {
-+		if (!zhdr->first_chunks)
-+			bud = FIRST;
-+		else if (!zhdr->last_chunks)
-+			bud = LAST;
-+		else
-+			bud = MIDDLE;
-+	}
-+
-+	return bud;
-+}
-+
- static inline void *mchunk_memmove(struct z3fold_header *zhdr,
- 				unsigned short dst_chunk)
- {
-@@ -682,18 +717,7 @@ static struct z3fold_header *compact_sin
- 		if (WARN_ON(new_zhdr == zhdr))
- 			goto out_fail;
- 
--		if (new_zhdr->first_chunks == 0) {
--			if (new_zhdr->middle_chunks != 0 &&
--					chunks >= new_zhdr->start_middle) {
--				new_bud = LAST;
--			} else {
--				new_bud = FIRST;
--			}
--		} else if (new_zhdr->last_chunks == 0) {
--			new_bud = LAST;
--		} else if (new_zhdr->middle_chunks == 0) {
--			new_bud = MIDDLE;
--		}
-+		new_bud = get_free_buddy(new_zhdr, chunks);
- 		q = new_zhdr;
- 		switch (new_bud) {
- 		case FIRST:
-@@ -815,9 +839,8 @@ static void do_compact_page(struct z3fol
- 		return;
- 	}
- 
--	if (unlikely(PageIsolated(page) ||
--		     test_bit(PAGE_CLAIMED, &page->private) ||
--		     test_bit(PAGE_STALE, &page->private))) {
-+	if (test_bit(PAGE_STALE, &page->private) ||
-+	    test_and_set_bit(PAGE_CLAIMED, &page->private)) {
- 		z3fold_page_unlock(zhdr);
- 		return;
- 	}
-@@ -826,13 +849,16 @@ static void do_compact_page(struct z3fol
- 	    zhdr->mapped_count == 0 && compact_single_buddy(zhdr)) {
- 		if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
- 			atomic64_dec(&pool->pages_nr);
--		else
-+		else {
-+			clear_bit(PAGE_CLAIMED, &page->private);
- 			z3fold_page_unlock(zhdr);
-+		}
- 		return;
- 	}
- 
- 	z3fold_compact_page(zhdr);
- 	add_to_unbuddied(pool, zhdr);
-+	clear_bit(PAGE_CLAIMED, &page->private);
- 	z3fold_page_unlock(zhdr);
- }
- 
-@@ -1080,17 +1106,8 @@ static int z3fold_alloc(struct z3fold_po
- retry:
- 		zhdr = __z3fold_alloc(pool, size, can_sleep);
- 		if (zhdr) {
--			if (zhdr->first_chunks == 0) {
--				if (zhdr->middle_chunks != 0 &&
--				    chunks >= zhdr->start_middle)
--					bud = LAST;
--				else
--					bud = FIRST;
--			} else if (zhdr->last_chunks == 0)
--				bud = LAST;
--			else if (zhdr->middle_chunks == 0)
--				bud = MIDDLE;
--			else {
-+			bud = get_free_buddy(zhdr, chunks);
-+			if (bud == HEADLESS) {
- 				if (kref_put(&zhdr->refcount,
- 					     release_z3fold_page_locked))
- 					atomic64_dec(&pool->pages_nr);
-@@ -1236,7 +1253,6 @@ static void z3fold_free(struct z3fold_po
- 		pr_err("%s: unknown bud %d\n", __func__, bud);
- 		WARN_ON(1);
- 		put_z3fold_header(zhdr);
--		clear_bit(PAGE_CLAIMED, &page->private);
- 		return;
- 	}
- 
-@@ -1251,8 +1267,7 @@ static void z3fold_free(struct z3fold_po
- 		z3fold_page_unlock(zhdr);
- 		return;
- 	}
--	if (unlikely(PageIsolated(page)) ||
--	    test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
-+	if (test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
- 		put_z3fold_header(zhdr);
- 		clear_bit(PAGE_CLAIMED, &page->private);
- 		return;
-@@ -1316,6 +1331,10 @@ static int z3fold_reclaim_page(struct z3
- 	struct page *page = NULL;
- 	struct list_head *pos;
- 	unsigned long first_handle = 0, middle_handle = 0, last_handle = 0;
-+	struct z3fold_buddy_slots slots __attribute__((aligned(SLOTS_ALIGN)));
-+
-+	rwlock_init(&slots.lock);
-+	slots.pool = (unsigned long)pool | (1 << HANDLES_NOFREE);
- 
- 	spin_lock(&pool->lock);
- 	if (!pool->ops || !pool->ops->evict || retries == 0) {
-@@ -1330,35 +1349,36 @@ static int z3fold_reclaim_page(struct z3
- 		list_for_each_prev(pos, &pool->lru) {
- 			page = list_entry(pos, struct page, lru);
- 
--			/* this bit could have been set by free, in which case
--			 * we pass over to the next page in the pool.
--			 */
--			if (test_and_set_bit(PAGE_CLAIMED, &page->private)) {
--				page = NULL;
--				continue;
--			}
--
--			if (unlikely(PageIsolated(page))) {
--				clear_bit(PAGE_CLAIMED, &page->private);
--				page = NULL;
--				continue;
--			}
- 			zhdr = page_address(page);
- 			if (test_bit(PAGE_HEADLESS, &page->private))
- 				break;
- 
-+			if (kref_get_unless_zero(&zhdr->refcount) == 0) {
-+				zhdr = NULL;
-+				break;
-+			}
- 			if (!z3fold_page_trylock(zhdr)) {
--				clear_bit(PAGE_CLAIMED, &page->private);
-+				if (kref_put(&zhdr->refcount,
-+						release_z3fold_page))
-+					atomic64_dec(&pool->pages_nr);
- 				zhdr = NULL;
- 				continue; /* can't evict at this point */
- 			}
--			if (zhdr->foreign_handles) {
--				clear_bit(PAGE_CLAIMED, &page->private);
--				z3fold_page_unlock(zhdr);
-+
-+			/* test_and_set_bit is of course atomic, but we still
-+			 * need to do it under page lock, otherwise checking
-+			 * that bit in __z3fold_alloc wouldn't make sense
-+			 */
-+			if (zhdr->foreign_handles ||
-+			    test_and_set_bit(PAGE_CLAIMED, &page->private)) {
-+				if (kref_put(&zhdr->refcount,
-+						release_z3fold_page))
-+					atomic64_dec(&pool->pages_nr);
-+				else
-+					z3fold_page_unlock(zhdr);
- 				zhdr = NULL;
- 				continue; /* can't evict such page */
- 			}
--			kref_get(&zhdr->refcount);
- 			list_del_init(&zhdr->buddy);
- 			zhdr->cpu = -1;
- 			break;
-@@ -1380,12 +1400,16 @@ static int z3fold_reclaim_page(struct z3
- 			first_handle = 0;
- 			last_handle = 0;
- 			middle_handle = 0;
-+			memset(slots.slot, 0, sizeof(slots.slot));
- 			if (zhdr->first_chunks)
--				first_handle = encode_handle(zhdr, FIRST);
-+				first_handle = __encode_handle(zhdr, &slots,
-+								FIRST);
- 			if (zhdr->middle_chunks)
--				middle_handle = encode_handle(zhdr, MIDDLE);
-+				middle_handle = __encode_handle(zhdr, &slots,
-+								MIDDLE);
- 			if (zhdr->last_chunks)
--				last_handle = encode_handle(zhdr, LAST);
-+				last_handle = __encode_handle(zhdr, &slots,
-+								LAST);
- 			/*
- 			 * it's safe to unlock here because we hold a
- 			 * reference to this page
-@@ -1400,19 +1424,16 @@ static int z3fold_reclaim_page(struct z3
- 			ret = pool->ops->evict(pool, middle_handle);
- 			if (ret)
- 				goto next;
--			free_handle(middle_handle, zhdr);
- 		}
- 		if (first_handle) {
- 			ret = pool->ops->evict(pool, first_handle);
- 			if (ret)
- 				goto next;
--			free_handle(first_handle, zhdr);
- 		}
- 		if (last_handle) {
- 			ret = pool->ops->evict(pool, last_handle);
- 			if (ret)
- 				goto next;
--			free_handle(last_handle, zhdr);
- 		}
- next:
- 		if (test_bit(PAGE_HEADLESS, &page->private)) {
-@@ -1426,9 +1447,11 @@ static int z3fold_reclaim_page(struct z3
- 			spin_unlock(&pool->lock);
- 			clear_bit(PAGE_CLAIMED, &page->private);
- 		} else {
-+			struct z3fold_buddy_slots *slots = zhdr->slots;
- 			z3fold_page_lock(zhdr);
- 			if (kref_put(&zhdr->refcount,
- 					release_z3fold_page_locked)) {
-+				kmem_cache_free(pool->c_handle, slots);
- 				atomic64_dec(&pool->pages_nr);
- 				return 0;
- 			}
-@@ -1544,8 +1567,7 @@ static bool z3fold_page_isolate(struct p
- 	VM_BUG_ON_PAGE(!PageMovable(page), page);
- 	VM_BUG_ON_PAGE(PageIsolated(page), page);
- 
--	if (test_bit(PAGE_HEADLESS, &page->private) ||
--	    test_bit(PAGE_CLAIMED, &page->private))
-+	if (test_bit(PAGE_HEADLESS, &page->private))
- 		return false;
- 
- 	zhdr = page_address(page);
-@@ -1557,6 +1579,8 @@ static bool z3fold_page_isolate(struct p
- 	if (zhdr->mapped_count != 0 || zhdr->foreign_handles != 0)
- 		goto out;
- 
-+	if (test_and_set_bit(PAGE_CLAIMED, &page->private))
-+		goto out;
- 	pool = zhdr_to_pool(zhdr);
- 	spin_lock(&pool->lock);
- 	if (!list_empty(&zhdr->buddy))
-@@ -1583,16 +1607,17 @@ static int z3fold_page_migrate(struct ad
- 
- 	VM_BUG_ON_PAGE(!PageMovable(page), page);
- 	VM_BUG_ON_PAGE(!PageIsolated(page), page);
-+	VM_BUG_ON_PAGE(!test_bit(PAGE_CLAIMED, &page->private), page);
- 	VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
- 
- 	zhdr = page_address(page);
- 	pool = zhdr_to_pool(zhdr);
- 
--	if (!z3fold_page_trylock(zhdr)) {
-+	if (!z3fold_page_trylock(zhdr))
- 		return -EAGAIN;
--	}
- 	if (zhdr->mapped_count != 0 || zhdr->foreign_handles != 0) {
- 		z3fold_page_unlock(zhdr);
-+		clear_bit(PAGE_CLAIMED, &page->private);
- 		return -EBUSY;
- 	}
- 	if (work_pending(&zhdr->work)) {
-@@ -1634,6 +1659,7 @@ static int z3fold_page_migrate(struct ad
- 	queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work);
- 
- 	page_mapcount_reset(page);
-+	clear_bit(PAGE_CLAIMED, &page->private);
- 	put_page(page);
- 	return 0;
- }
-@@ -1657,6 +1683,7 @@ static void z3fold_page_putback(struct p
- 	spin_lock(&pool->lock);
- 	list_add(&page->lru, &pool->lru);
- 	spin_unlock(&pool->lock);
-+	clear_bit(PAGE_CLAIMED, &page->private);
- 	z3fold_page_unlock(zhdr);
- }
- 
diff --git a/patches/localversion.patch b/patches/localversion.patch
index d7c1a50b87ee..bba4391fd1bd 100644
--- a/patches/localversion.patch
+++ b/patches/localversion.patch
@@ -10,4 +10,4 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 --- /dev/null
 +++ b/localversion-rt
 @@ -0,0 +1 @@
-+-rt20
++-rt21
diff --git a/patches/sched-mmdrop-delayed.patch b/patches/sched-mmdrop-delayed.patch
index 46a0bf2fd08e..17d86492aefc 100644
--- a/patches/sched-mmdrop-delayed.patch
+++ b/patches/sched-mmdrop-delayed.patch
@@ -22,8 +22,8 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
 +#include <linux/rcupdate.h>
  #include <linux/page-flags-layout.h>
  #include <linux/workqueue.h>
- 
-@@ -548,6 +549,9 @@ struct mm_struct {
+ #include <linux/seqlock.h>
+@@ -556,6 +557,9 @@ struct mm_struct {
  		bool tlb_flush_batched;
  #endif
  		struct uprobes_state uprobes_state;
@@ -92,7 +92,7 @@ Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  	}
  	if (unlikely(prev_state == TASK_DEAD)) {
  		if (prev->sched_class->task_dead)
-@@ -7269,6 +7273,7 @@ void sched_setnuma(struct task_struct *p
+@@ -7265,6 +7269,7 @@ void sched_setnuma(struct task_struct *p
  #endif /* CONFIG_NUMA_BALANCING */
  
  #ifdef CONFIG_HOTPLUG_CPU
diff --git a/patches/series b/patches/series
index b9975fd0af51..949197974061 100644
--- a/patches/series
+++ b/patches/series
@@ -5,9 +5,7 @@
 ############################################################
 # UPSTREAM merged
 ############################################################
-# z3fold, fc5488651c7d840c9cad9b0f273f2f31bd03413a+
-0001-z3fold-simplify-freeing-slots.patch
-0002-z3fold-stricter-locking-and-more-careful-reclaim.patch
+# z3fold, 135f97fd0c398f20a544cc52c3f8a3cb925a8aef
 0003-z3fold-remove-preempt-disabled-sections-for-RT.patch
 
 ############################################################