5.6-stable patches

added patches:
	revert-virtio-balloon-revert-virtio-balloon-switch-back-to-oom-handler-for-virtio_balloon_f_deflate_on_oom.patch

diff --git a/queue-5.6/revert-virtio-balloon-revert-virtio-balloon-switch-back-to-oom-handler-for-virtio_balloon_f_deflate_on_oom.patch b/queue-5.6/revert-virtio-balloon-revert-virtio-balloon-switch-back-to-oom-handler-for-virtio_balloon_f_deflate_on_oom.patch
new file mode 100644 (file)
index 0000000..129de38
--- /dev/null
+++ b/queue-5.6/revert-virtio-balloon-revert-virtio-balloon-switch-back-to-oom-handler-for-virtio_balloon_f_deflate_on_oom.patch
@@ -0,0 +1,202 @@
+From ee40bf5d704c75938fcd4e4e74d8dbed5b7b9999 Mon Sep 17 00:00:00 2001
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Date: Thu, 28 May 2020 13:30:53 +0200
+Subject: Revert "virtio-balloon: Revert "virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM""
+
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+This reverts commit 37681282be8e89ae8baf26753bf489837d74e08e which is
+commit 835a6a649d0dd1b1f46759eb60fff2f63ed253a7 upstream.
+
+Jiri and David agree that it is not needed in the 5.6.y tree, so revert
+it.
+
+Reported-by: Jiri Slaby <jslaby@suse.cz>
+Reported-by: David Hildenbrand <david@redhat.com>
+Cc: Michael S. Tsirkin <mst@redhat.com>
+Cc: Sasha Levin <sashal@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/virtio/virtio_balloon.c |  107 ++++++++++++++++------------------------
+ 1 file changed, 44 insertions(+), 63 deletions(-)
+
+--- a/drivers/virtio/virtio_balloon.c
++++ b/drivers/virtio/virtio_balloon.c
+@@ -14,6 +14,7 @@
+ #include <linux/slab.h>
+ #include <linux/module.h>
+ #include <linux/balloon_compaction.h>
++#include <linux/oom.h>
+ #include <linux/wait.h>
+ #include <linux/mm.h>
+ #include <linux/mount.h>
+@@ -27,7 +28,9 @@
+  */
+ #define VIRTIO_BALLOON_PAGES_PER_PAGE (unsigned)(PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT)
+ #define VIRTIO_BALLOON_ARRAY_PFNS_MAX 256
+-#define VIRTBALLOON_OOM_NOTIFY_PRIORITY 80
++/* Maximum number of (4k) pages to deflate on OOM notifications. */
++#define VIRTIO_BALLOON_OOM_NR_PAGES 256
++#define VIRTIO_BALLOON_OOM_NOTIFY_PRIORITY 80
+ 
+ #define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \
+                                            __GFP_NOMEMALLOC)
+@@ -112,8 +115,11 @@ struct virtio_balloon {
+       /* Memory statistics */
+       struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR];
+ 
+-      /* To register a shrinker to shrink memory upon memory pressure */
++      /* Shrinker to return free pages - VIRTIO_BALLOON_F_FREE_PAGE_HINT */
+       struct shrinker shrinker;
++
++      /* OOM notifier to deflate on OOM - VIRTIO_BALLOON_F_DEFLATE_ON_OOM */
++      struct notifier_block oom_nb;
+ };
+ 
+ static struct virtio_device_id id_table[] = {
+@@ -788,50 +794,13 @@ static unsigned long shrink_free_pages(s
+       return blocks_freed * VIRTIO_BALLOON_HINT_BLOCK_PAGES;
+ }
+ 
+-static unsigned long leak_balloon_pages(struct virtio_balloon *vb,
+-                                          unsigned long pages_to_free)
+-{
+-      return leak_balloon(vb, pages_to_free * VIRTIO_BALLOON_PAGES_PER_PAGE) /
+-              VIRTIO_BALLOON_PAGES_PER_PAGE;
+-}
+-
+-static unsigned long shrink_balloon_pages(struct virtio_balloon *vb,
+-                                        unsigned long pages_to_free)
+-{
+-      unsigned long pages_freed = 0;
+-
+-      /*
+-       * One invocation of leak_balloon can deflate at most
+-       * VIRTIO_BALLOON_ARRAY_PFNS_MAX balloon pages, so we call it
+-       * multiple times to deflate pages till reaching pages_to_free.
+-       */
+-      while (vb->num_pages && pages_freed < pages_to_free)
+-              pages_freed += leak_balloon_pages(vb,
+-                                                pages_to_free - pages_freed);
+-
+-      update_balloon_size(vb);
+-
+-      return pages_freed;
+-}
+-
+ static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker,
+                                                 struct shrink_control *sc)
+ {
+-      unsigned long pages_to_free, pages_freed = 0;
+       struct virtio_balloon *vb = container_of(shrinker,
+                                       struct virtio_balloon, shrinker);
+ 
+-      pages_to_free = sc->nr_to_scan;
+-
+-      if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+-              pages_freed = shrink_free_pages(vb, pages_to_free);
+-
+-      if (pages_freed >= pages_to_free)
+-              return pages_freed;
+-
+-      pages_freed += shrink_balloon_pages(vb, pages_to_free - pages_freed);
+-
+-      return pages_freed;
++      return shrink_free_pages(vb, sc->nr_to_scan);
+ }
+ 
+ static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker,
+@@ -839,26 +808,22 @@ static unsigned long virtio_balloon_shri
+ {
+       struct virtio_balloon *vb = container_of(shrinker,
+                                       struct virtio_balloon, shrinker);
+-      unsigned long count;
+-
+-      count = vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE;
+-      count += vb->num_free_page_blocks * VIRTIO_BALLOON_HINT_BLOCK_PAGES;
+ 
+-      return count;
++      return vb->num_free_page_blocks * VIRTIO_BALLOON_HINT_BLOCK_PAGES;
+ }
+ 
+-static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb)
++static int virtio_balloon_oom_notify(struct notifier_block *nb,
++                                   unsigned long dummy, void *parm)
+ {
+-      unregister_shrinker(&vb->shrinker);
+-}
++      struct virtio_balloon *vb = container_of(nb,
++                                               struct virtio_balloon, oom_nb);
++      unsigned long *freed = parm;
+ 
+-static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
+-{
+-      vb->shrinker.scan_objects = virtio_balloon_shrinker_scan;
+-      vb->shrinker.count_objects = virtio_balloon_shrinker_count;
+-      vb->shrinker.seeks = DEFAULT_SEEKS;
++      *freed += leak_balloon(vb, VIRTIO_BALLOON_OOM_NR_PAGES) /
++                VIRTIO_BALLOON_PAGES_PER_PAGE;
++      update_balloon_size(vb);
+ 
+-      return register_shrinker(&vb->shrinker);
++      return NOTIFY_OK;
+ }
+ 
+ static int virtballoon_probe(struct virtio_device *vdev)
+@@ -935,22 +900,35 @@ static int virtballoon_probe(struct virt
+                       virtio_cwrite(vb->vdev, struct virtio_balloon_config,
+                                     poison_val, &poison_val);
+               }
+-      }
+-      /*
+-       * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a
+-       * shrinker needs to be registered to relieve memory pressure.
+-       */
+-      if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) {
+-              err = virtio_balloon_register_shrinker(vb);
++
++              /*
++               * We're allowed to reuse any free pages, even if they are
++               * still to be processed by the host.
++               */
++              vb->shrinker.scan_objects = virtio_balloon_shrinker_scan;
++              vb->shrinker.count_objects = virtio_balloon_shrinker_count;
++              vb->shrinker.seeks = DEFAULT_SEEKS;
++              err = register_shrinker(&vb->shrinker);
+               if (err)
+                       goto out_del_balloon_wq;
+       }
++      if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) {
++              vb->oom_nb.notifier_call = virtio_balloon_oom_notify;
++              vb->oom_nb.priority = VIRTIO_BALLOON_OOM_NOTIFY_PRIORITY;
++              err = register_oom_notifier(&vb->oom_nb);
++              if (err < 0)
++                      goto out_unregister_shrinker;
++      }
++
+       virtio_device_ready(vdev);
+ 
+       if (towards_target(vb))
+               virtballoon_changed(vdev);
+       return 0;
+ 
++out_unregister_shrinker:
++      if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
++              unregister_shrinker(&vb->shrinker);
+ out_del_balloon_wq:
+       if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+               destroy_workqueue(vb->balloon_wq);
+@@ -989,8 +967,11 @@ static void virtballoon_remove(struct vi
+ {
+       struct virtio_balloon *vb = vdev->priv;
+ 
+-      if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
+-              virtio_balloon_unregister_shrinker(vb);
++      if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM))
++              unregister_oom_notifier(&vb->oom_nb);
++      if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
++              unregister_shrinker(&vb->shrinker);
++
+       spin_lock_irq(&vb->stop_update_lock);
+       vb->stop_update = true;
+       spin_unlock_irq(&vb->stop_update_lock);

diff --git a/queue-5.6/series b/queue-5.6/series
index bcf12efcbc2d403489ff063ac06175d74911ba65..3ac89ab89bfd0b273b216dd82b24e51d7fe6ed67 100644 (file)
--- a/queue-5.6/series
+++ b/queue-5.6/series
@@ -31,3 +31,4 @@ wireguard-noise-separate-receive-counter-from-send-counter.patch
 r8169-fix-ocp-access-on-rtl8117.patch
 net-mlx5-fix-a-race-when-moving-command-interface-to-events-mode.patch
 net-mlx5-fix-cleaning-unmanaged-flow-tables.patch
+revert-virtio-balloon-revert-virtio-balloon-switch-back-to-oom-handler-for-virtio_balloon_f_deflate_on_oom.patch