Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio barrier rework+fixes from Michael Tsirkin:
 "This adds a new kind of barrier, and reworks virtio and xen to use it.

  Plus some fixes here and there"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (44 commits)
  checkpatch: add virt barriers
  checkpatch: check for __smp outside barrier.h
  checkpatch.pl: add missing memory barriers
  virtio: make find_vqs() checkpatch.pl-friendly
  virtio_balloon: fix race between migration and ballooning
  virtio_balloon: fix race by fill and leak
  s390: more efficient smp barriers
  s390: use generic memory barriers
  xen/events: use virt_xxx barriers
  xen/io: use virt_xxx barriers
  xenbus: use virt_xxx barriers
  virtio_ring: use virt_store_mb
  sh: move xchg_cmpxchg to a header by itself
  sh: support 1 and 2 byte xchg
  virtio_ring: update weak barriers to use virt_xxx
  Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb"
  asm-generic: implement virt_xxx memory barriers
  x86: define __smp_xxx
  xtensa: define __smp_xxx
  tile: define __smp_xxx
  ...

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index d3116be5a00f..300117f1a08f 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -61,6 +61,7 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info)
         bool dequeued_page;
 
         dequeued_page = false;
+        spin_lock_irqsave(&b_dev_info->pages_lock, flags);
         list_for_each_entry_safe(page, tmp, &b_dev_info->pages, lru) {
                 /*
                  * Block others from accessing the 'page' while we get around
@@ -75,15 +76,14 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info)
                                 continue;
                         }
 #endif
-                        spin_lock_irqsave(&b_dev_info->pages_lock, flags);
                         balloon_page_delete(page);
                         __count_vm_event(BALLOON_DEFLATE);
-                        spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
                         unlock_page(page);
                         dequeued_page = true;
                         break;
                 }
         }
+        spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
 
         if (!dequeued_page) {
                 /*