This check is necessary to avoid race between dequeue and allocation,
which can cause a free hugepage to be dequeued twice and get kernel unstable.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
This patch extends page migration code to support hugepage migration.
One of the potential users of this feature is soft offlining which
is triggered by memory corrected errors (added by the next patch.)
Todo:
- there are other users of page migration such as memory policy,
memory hotplug and memocy compaction.
They are not ready for hugepage support for now.
ChangeLog since v4:
- define migrate_huge_pages()
- remove changes on isolation/putback_lru_page()
ChangeLog since v2:
- refactor isolate/putback_lru_page() to handle hugepage
- add comment about race on unmap_and_move_huge_page()
ChangeLog since v1:
- divide migration code path for hugepage
- define routine checking migration swap entry for hugetlb
- replace "goto" with "if/else" in remove_migration_pte()
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
This patch modifies hugepage copy functions to have only destination
and source hugepages as arguments for later use.
The old ones are renamed from copy_{gigantic,huge}_page() to
copy_user_{gigantic,huge}_page().
This naming convention is consistent with that between copy_highpage()
and copy_user_highpage().
ChangeLog since v4:
- add blank line between local declaration and code
- remove unnecessary might_sleep()
ChangeLog since v2:
- change copy_huge_page() from macro to inline dummy function
to avoid compile warning when !CONFIG_HUGETLB_PAGE.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
We can't use existing hugepage allocation functions to allocate hugepage
for page migration, because page migration can happen asynchronously with
the running processes and page migration users should call the allocation
function with physical addresses (not virtual addresses) as arguments.
ChangeLog since v3:
- unify alloc_buddy_huge_page() and alloc_buddy_huge_page_node()
ChangeLog since v2:
- remove unnecessary get/put_mems_allowed() (thanks to David Rientjes)
ChangeLog since v1:
- add comment on top of alloc_huge_page_no_vma()
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Since the PageHWPoison() check is for avoiding hwpoisoned page remained
in pagecache mapping to the process, it should be done in "found in pagecache"
branch, not in the common path.
Otherwise, metadata corruption occurs if memory failure happens between
alloc_huge_page() and lock_page() because page fault fails with metadata
changes remained (such as refcount, mapcount, etc.)
This patch moves the check to "found in pagecache" branch and fix the problem.
ChangeLog since v2:
- remove retry check in "new allocation" path.
- make description more detailed
- change patch name from "HWPOISON, hugetlb: move PG_HWPoison bit check"
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
* 'hwpoison-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
HWPOISON: Stop shrinking at right page count
HWPOISON: Report correct address granuality for AO huge page errors
HWPOISON: Copy si_addr_lsb to user
page-types.c: fix name of unpoison interface
* 'for-linus' of git://neil.brown.name/md:
md: check return code of read_sb_page
md/raid1: minor bio initialisation improvements.
md/raid1: avoid overflow in raid1 resync when bitmap is in use.
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm: don't drop handle reference on unload
drm/ttm: Fix two race conditions + fix busy codepaths
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
of/i2c: Fix module load order issue caused by of_i2c.c
i2c: Fix checks which cause legacy suspend to never get called
i2c-pca: Fix waitforcompletion() return value
i2c: Fix for suspend/resume issue
i2c: Remove obsolete cleanup for clientdata
When proc_doulongvec_minmax() is used with an array of longs, and no
min/max check requested (.extra1 or .extra2 being NULL), we dereference a
NULL pointer for the second element of the array.
Noticed while doing some changes in network stack for the "16TB problem"
Fix is to not change min & max pointers in __do_proc_doulongvec_minmax(),
so that all elements of the vector share an unique min/max limit, like
proc_dointvec_minmax().
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we call the slab shrinker to free a page we need to stop at
page count one because the caller always holds a single reference, not zero.
This avoids useless looping over slab shrinkers and freeing too much
memory.
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
The SIGBUS user space signalling is supposed to report the
address granuality of a corruption. Pass this information correctly
for huge pages by querying the hpage order.
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
The original hwpoison code added a new siginfo field si_addr_lsb to
pass the granuality of the fault address to user space. Unfortunately
this field was never copied to user space. Fix this here.
I added explicit checks for the MCEERR codes to avoid having
to patch all potential callers to initialize the field.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
The page-types utility still uses an out of date name for the
unpoison interface: debugfs:hwpoison/renew-pfn
This patch renames and fixes it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2.6.36 introduces an API for drivers to switch the IO scheduler
instead of manually calling the elevator exit and init functions.
This API was added since q->elevator must be cleared in between
those two calls. And since we already have this functionality
directly from use by the sysfs interface to switch schedulers
online, it was prudent to reuse it internally too.
But this API needs the queue to be in a fully initialized state
before it is called, or it will attempt to unregister elevator
kobjects before they have been added. This results in an oops
like this:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000051
IP: [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
PGD 47ddfc067 PUD 47c6a1067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:04:00.1/irq
CPU 2
Modules linked in: t(+) loop hid_apple usbhid ahci ehci_hcd uhci_hcd libahci usbcore nls_base igb
Pid: 7319, comm: modprobe Not tainted 2.6.36-rc6+ #132 QSSC-S4R/QSSC-S4R
RIP: 0010:[<ffffffff8116f15e>] [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
RSP: 0018:ffff88027da25d08 EFLAGS: 00010246
RAX: ffff88047c68c528 RBX: 00000000fffffffe RCX: 0000000000000000
RDX: 000000000000002f RSI: 000000000000002f RDI: ffff88047e196c88
RBP: ffff88027da25d38 R08: 0000000000000000 R09: d84156c5635688c0
R10: d84156c5635688c0 R11: 0000000000000000 R12: ffff88047e196c88
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88047c68c528
FS: 00007fcb0b26f6e0(0000) GS:ffff880287400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000051 CR3: 000000047e76e000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process modprobe (pid: 7319, threadinfo ffff88027da24000, task ffff88027d377090)
Stack:
ffff88027da25d58 ffff88047c68c528 00000000fffffffe ffff88047e196c88
<0> ffff88047c68c528 ffff88047e05bd90 ffff88027da25d78 ffffffff8123fb77
<0> ffff88047e05bd90 0000000000000000 ffff88047e196c88 ffff88047c68c528
Call Trace:
[<ffffffff8123fb77>] kobject_add_internal+0xe7/0x1f0
[<ffffffff8123fd98>] kobject_add_varg+0x38/0x60
[<ffffffff8123feb9>] kobject_add+0x69/0x90
[<ffffffff8116efe0>] ? sysfs_remove_dir+0x20/0xa0
[<ffffffff8103d48d>] ? sub_preempt_count+0x9d/0xe0
[<ffffffff8143de20>] ? _raw_spin_unlock+0x30/0x50
[<ffffffff8116efe0>] ? sysfs_remove_dir+0x20/0xa0
[<ffffffff8116eff4>] ? sysfs_remove_dir+0x34/0xa0
[<ffffffff81224204>] elv_register_queue+0x34/0xa0
[<ffffffff81224aad>] elevator_change+0xfd/0x250
[<ffffffffa007e000>] ? t_init+0x0/0x361 [t]
[<ffffffffa007e000>] ? t_init+0x0/0x361 [t]
[<ffffffffa007e0a8>] t_init+0xa8/0x361 [t]
[<ffffffff810001de>] do_one_initcall+0x3e/0x170
[<ffffffff8108c3fd>] sys_init_module+0xbd/0x220
[<ffffffff81002f2b>] system_call_fastpath+0x16/0x1b
Code: e5 41 56 41 55 41 54 49 89 fc 53 48 83 ec 10 48 85 ff 74 52 48 8b 47 18 49 c7 c5 00 46 61 81 48 85 c0 74 04 4c 8b 68 30 45 31 f6 <41> 80 7d 51 00 74 0e 49 8b 44 24 28 4c 89 e7 ff 50 20 49 89 c6
RIP [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
RSP <ffff88027da25d08>
CR2: 0000000000000051
---[ end trace a6541d3bf07945df ]---
Fix this by adding a registered bit to the elevator queue, which is
set when the sysfs kobjects have been registered.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
since the handle references are all tied to a file_priv, and when it disappears
all the handle refs go with it.
The fbcon ones we'd only notice on unload, but the nouveau notifier one
would would happen on reboot.
nouveau: Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
nouveau: Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
i915 unload: Reported-by: Keith Packard <keithp@keithp.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
When marking an inode reclaimable, a per-AG counter is increased, the
inode is tagged reclaimable in its per-AG tree, and, when this is the
first reclaimable inode in the AG, the AG entry in the per-mount tree
is also tagged.
When an inode is finally reclaimed, however, it is only deleted from
the per-AG tree. Neither the counter is decreased, nor is the parent
tree's AG entry untagged properly.
Since the tags in the per-mount tree are not cleared, the inode
shrinker iterates over all AGs that have had reclaimable inodes at one
point in time.
The counters on the other hand signal an increasing amount of slab
objects to reclaim. Since "70e60ce xfs: convert inode shrinker to
per-filesystem context" this is not a real issue anymore because the
shrinker bails out after one iteration.
But the problem was observable on a machine running v2.6.34, where the
reclaimable work increased and each process going into direct reclaim
eventually got stuck on the xfs inode shrinking path, trying to scan
several million objects.
Fix this by properly unwinding the reclaimable-state tracking of an
inode when it is reclaimed.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@kernel.org
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Naoya Horiguchi
Linus Torvalds
Eric Dumazet
Kyungmin Park
Andrew Morton
Kirill A. Shutemov
Robin Holt
Andi Kleen
Jens Axboe
Dave Airlie
Johannes Weiner