linux/arch/x86
Dan Williams 220ced1676 mm: fix get_user_pages() vs device-dax pud mappings
A new unit test for the device-dax 1GB enabling currently fails with
this warning before hanging the test thread:

 WARNING: CPU: 0 PID: 21 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x1e3/0x1f0
 percpu ref (dax_pmem_percpu_release [dax_pmem]) <= 0 (0) after switching to atomic
 [..]
 CPU: 0 PID: 21 Comm: rcuos/1 Tainted: G           O    4.10.0-rc7-next-20170207+ #944
 [..]
 Call Trace:
  dump_stack+0x86/0xc3
  __warn+0xcb/0xf0
  warn_slowpath_fmt+0x5f/0x80
  ? rcu_nocb_kthread+0x27a/0x510
  ? dax_pmem_percpu_exit+0x50/0x50 [dax_pmem]
  percpu_ref_switch_to_atomic_rcu+0x1e3/0x1f0
  ? percpu_ref_exit+0x60/0x60
  rcu_nocb_kthread+0x339/0x510
  ? rcu_nocb_kthread+0x27a/0x510
  kthread+0x101/0x140

The get_user_pages() path needs to arrange for references to be taken
against the dev_pagemap instance backing the pud mapping.  Refactor the
existing __gup_device_huge_pmd() to also account for the pud case.

Link: http://lkml.kernel.org/r/148653181153.38226.9605457830505509385.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
..
boot Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 14:04:37 -08:00
configs IOMMU Updates for Linux v4.9 2016-10-11 12:52:41 -07:00
crypto crypto: sha512-mb - Protect sha512 mb ctx mgr access 2017-02-11 17:50:41 +08:00
entry x86/entry: Fix the end of the stack for newly forked tasks 2017-01-12 09:28:29 +01:00
events perf/x86/intel: Add Kaby Lake support 2017-02-11 21:28:23 +01:00
hyperv drivers: hv: Turn off write permission on the hypercall page 2017-02-10 15:48:00 +01:00
ia32 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
include mm, x86: add support for PUD-sized transparent hugepages 2017-02-24 17:46:54 -08:00
kernel mm, x86: add support for PUD-sized transparent hugepages 2017-02-24 17:46:54 -08:00
kvm 4.11 is going to be a relatively large release for KVM, with a little over 2017-02-22 18:22:53 -08:00
lguest clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
lib x86/timer: Make delay() work during early bootup 2017-01-22 10:03:12 +01:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm mm: fix get_user_pages() vs device-dax pud mappings 2017-02-24 17:46:54 -08:00
net bpf: fix unlocking of jited image when module ronx not set 2017-02-21 13:30:14 -05:00
oprofile x86/oprofile/nmi: Convert to hotplug state machine 2016-11-22 23:34:43 +01:00
pci x86/PCI: Ignore _CRS on Supermicro X8DTH-i/6/iF/6F 2017-01-11 09:11:15 -06:00
platform char/misc driver patches for 4.11-rc1 2017-02-22 11:38:22 -08:00
power Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-18 13:59:10 -08:00
purgatory x86/kexec: add -fno-PIE 2016-11-09 22:28:09 +01:00
ras x86/ras/amd/inj: Change dependency 2017-01-24 09:14:55 +01:00
realmode x86/build: Don't use $(LINUXINCLUDE) twice 2016-11-28 07:49:17 +01:00
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
video
xen xen: features and fixes for 4.11-rc0 2017-02-21 13:53:41 -08:00
.gitignore
Kbuild Drivers: hv vmbus: Move Hypercall page setup out of common code 2017-01-19 11:42:07 +01:00
Kconfig mm, x86: add support for PUD-sized transparent hugepages 2017-02-24 17:46:54 -08:00
Kconfig.cpu
Kconfig.debug This renames the (now inaccurate) CONFIG_DEBUG_RODATA and related config 2017-02-21 17:56:45 -08:00
Makefile lib/raid6: Add AVX512 optimized gen_syndrome functions 2016-09-21 09:09:44 -07:00
Makefile_32.cpu
Makefile.um