** Also affects: linux (Ubuntu Zesty)
   Importance: Undecided
       Status: New

** Changed in: linux (Ubuntu Zesty)
   Importance: Undecided => High

** Changed in: linux (Ubuntu Zesty)
       Status: New => Fix Committed

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1696165

Title:
  [SRU][Zesty] fix soft lockup on overcommited hugepages

Status in linux package in Ubuntu:
  Incomplete
Status in linux source package in Zesty:
  Fix Committed

Bug description:
  [Impact]
  On failing to migrate a page, soft_offline_huge_page() performs the necessary 
update to the hugepage ref-count.

  But when !hugepage_migration_supported() , unmap_and_move_hugepage()
  also decrements the page ref-count for the hugepage. The combined
  behaviour leaves the ref-count in an inconsistent state.

  This leads to soft lockups when running the overcommitted hugepage
  test from mce-tests suite

  [Testing]
  Run the mce-test/cases/function/hwpoison/run_hugepage_overcommit.sh and you 
should see softlock up if hugepage migration support is not enabled.

  [Fix]
  upstream commit:
  30809f559a0d mm/migrate: fix refcount handling when 
!hugepage_migration_supported()

  [Regression Potential]

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1696165/+subscriptions

-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to