If no devices found or invalid parameter is specified,
scl200wdt_pnp_driver is left unregistered.
It breaks global list of pnp drivers.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@osdl.org>
prepare_reply() adds GENL_HDRLEN to the payload (genlmsg_total_size()),
but then it does genlmsg_put()->nlmsg_put(). This means we forget to
reserve a room for 'struct nlmsghdr'.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
'return genlmsg_cancel()' in taskstats_user_cmd/taskstats_exit_send
potentially leaks a skb. Unless we pass 'rep_skb' to the netlink layer
we own sk_buff. This means we should always do kfree_skb() on failure.
[ Thomas acked and pointed out missing return value in original version ]
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Thomas Graf <tgraf@suug.ch>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some errors during preparation for suspended state can be skipped with a
warning instead of a failure of the whole suspend transition, notably an
error in pci_set_power_state.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The second ethernet port on the Thecus n2100 was incorrectly assigned
to XINT1 instead of the correct XINT3 (PCI INTB instead of INTD), which
caused that port to be non-functional.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As reported by Martin J. Bligh <mbligh@google.com>, we let through some
non-slab bits to slab allocation through __get_vm_area_node when doing a
vmalloc.
I haven't been able to reproduce this, although I understand why it
happens: vmalloc allocates memory with
GFP_KERNEL | __GFP_HIGHMEM
and commit 52fd24ca1d resulted in the same
flags are passed down to cache_alloc_refill, causing the BUG. The
following patch fixes it.
Note that when calling kmalloc_node, I am masking off __GFP_HIGHMEM with
GFP_LEVEL_MASK, whereas __vmalloc_area_node does the same with
~(__GFP_HIGHMEM | __GFP_ZERO).
IMHO, using GFP_LEVEL_MASK is preferable, but either should fix this
problem.
Signed-off-by: Giridhar Pemmasani (pgiri@yahoo.com)
Cc: Martin J. Bligh <mbligh@google.com>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add support for KBUILD_IMAGE on ARM. This takes the usual target
specifiers (zImage/Image/etc) in the same way that powerpc does
(iow, without the arch/arm/boot prefix).
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The PXA2xx PCMCIA driver was registering a device_driver with the
platform_bus_type. Unfortunately, this causes data outside the
device_driver structure to be dereferenced as if it were a
platform_driver structure, causing an oops. Convert the PXA2xx
core driver to use the proper platform_driver structure.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
i2c-pxa times out when trying to enable slave mode due to an
incorrect test. Also, check that i2c->slave is non-NULL
before dereferencing it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] cio: Make ccw_device_register() static.
[S390] Improve AP bus device removal.
[S390] uaccess error handling.
[S390] cio: css_probe_device() must be called enabled.
[S390] Initialize interval value to 0.
[S390] sys_getcpu compat wrapper.
absent_pages_in_range() made the assumption that users of the
arch-independent zone-sizing API would not care about holes beyound the end
of physical memory. This was not the case and was "fixed" in a patch
called "Account for holes that are outside the range of physical memory".
However, when given a range that started before a hole in "real" memory and
ended beyond the end of memory, it would get the result wrong. The bug is
in mainline but a patch is below.
It has been tested successfully on a number of machines and architectures.
Additional credit to Keith Mannthey for discovering the problem, helping
identify the correct fix and confirming it Worked For Him.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: keith mannthey <kmannth@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch (as812) changes the kerneldoc comments explaining the return
values from queue_work(), queue_delayed_work(), and
queue_delayed_work_on(). The updated comments explain more accurately the
meaning of the return code and avoid suggesting that a 0 value means the
routine was unsuccessful.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The Jmicron JMB368 is PATA only so has the PATA on function zero. Don't
therefore skip function zero on this device when probing
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
_cpu_down() acquires `workqueue_mutex' on its process, but doen't release it
if __cpu_disable() fails.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I notice that the code which implements adjtime clears the time_adjust
value before using it. The attached patch makes the obvious fix.
Acked-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Jim Houston <jim.houston@ccur.com>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Put SYS_HYPERVISOR inside the Generic Driver Config menu where it should
be. Otherwise xconfig displays it as a dangling (lost) menu item under
Device Drivers, all by itself (when all options are displayed).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <holzheu@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fill_tgid() should skip not only an already exited group leader. If the
task has ->exit_state != 0 it already did exit_notify(), so it also did
fill_tgid_exit()->delayacct_add_tsk(->signal->stats) and we should skip it
to avoid a double accounting.
This patch doesn't close the race completely, but it cleanups the code.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove tasklist_lock from taskstats.c. find_task_by_pid() is rcu-safe.
->siglock allows us to traverse subthread without tasklist.
Q: delay accounting looks wrong to me. If sub-thread has already called
taskstats_exit_send() but didn't call release_task(self) yet it will be
accounted twice. The window is big. No?
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
signal_struct is (mostly) protected by ->sighand->siglock, I think we don't
need ->taskstats_lock to protect ->stats. This also allows us to simplify the
locking in fill_tgid().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
taskstats_tgid_free() is called on copy_process's error path. This is wrong.
IF (clone_flags & CLONE_THREAD)
We should not clear ->signal->taskstats, current uses it,
it probably has a valid accumulated info.
ELSE
taskstats_tgid_init() set ->signal->taskstats = NULL,
there is nothing to free.
Move the callsite to __exit_signal(). We don't need any locking, entire
thread group is exiting, nobody should have a reference to soon to be
released ->signal.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1. ts = timespec_sub(uptime, current->group_leader->start_time);
It is possible that current != tsk. Probably it was supposed
to be 'tsk->group_leader->start_time. But why we are reading
group_leader's start_time ? This accounting is per thread,
not per procees, I changed this to 'tsk->start_time.
Please corect me.
2. stats->ac_ppid = (tsk->parent) ? tsk->parent->pid : 0;
tsk->parent never == NULL, and it is unsafe to dereference it.
Both the task and it's parent may exit after the caller unlocks
tasklist_lock, the memory could be unmapped (DEBUG_SLAB).
(And we should use ->real_parent->tgid in fact).
Q: I don't understand the 'if (thread_group_leader(tsk))' check.
Why it is needed ?
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: Jay Lan <jlan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1. fill_tgid() forgets to do put_task_struct(first).
2. release_task(first) can happen after fill_tgid() drops tasklist_lock,
it is unsafe to dereference first->signal.
This is a temporary fix, imho the locking should be reworked.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
strstrip() does not remove the last blank from strings which only consist
of blanks.
Example:
char string[] = " ";
strstrip(string);
results in " ", but should produce an empty string!
The following patch solves this problem:
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by Joern Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This means we can call it when the bitmap we want to fetch is declared
const.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With Vasily Averin <vvs@sw.ru>
Fix an error in unused dentry counting in shrink_dcache_for_umount_subtree()
in which the count is modified without the dcache_lock held.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Vasily Averin <vvs@sw.ru>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On the the following patch:
http://linux.bkbits.net:8080/linux-2.6/gnupatch@449b144ecSF1rYskg3q-SeR2vf88zg
# ChangeSet
# 2006/06/22 15:05:57-07:00 neilb@suse.de
# [PATCH] Fix dcache race during umount
# If prune_dcache finds a dentry that it cannot free, it leaves it where it
# is (at the tail of the list) and exits, on the assumption that some other
# thread will be removing that dentry soon.
However as far as I see this comment is not correct: when we cannot take
s_umount rw_semaphore (for example because it was taken in do_remount) this
dentry is already extracted from dentry_unused list and we do not add it
into the list again. Therefore dentry will not be found by prune_dcache()
and shrink_dcache_sb() and will leave in memory very long time until the
partition will be unmounted.
The patch adds this dentry into tail of the dentry_unused list.
Signed-off-by: Vasily Averin <vvs@sw.ru>
Cc: Neil Brown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If you truncated an mmap'ed hugetlbfs file, then faulted on the truncated
area, /proc/meminfo's HugePages_Rsvd wrapped hugely "negative". Reinstate my
preliminary i_size check before attempting to allocate the page (though this
only fixes the most obvious case: more work will be needed here).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
hugetlb_vmtruncate_list was misconverted to prio_tree: its prio_tree is in
units of PAGE_SIZE (PAGE_CACHE_SIZE) like any other, not HPAGE_SIZE (whereas
its radix_tree is kept in units of HPAGE_SIZE, otherwise slots would be
absurdly sparse).
At first I thought the error benign, just calling __unmap_hugepage_range on
more vmas than necessary; but on 32-bit machines, when the prio_tree is
searched correctly, it happens to ensure the v_offset calculation won't
overflow. As it stood, when truncating at or beyond 4GB, it was liable to
discard pages COWed from lower offsets; or even to clear pmd entries of
preceding vmas, triggering exit_mmap's BUG_ON(nr_ptes).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On 32-bit machines, mount -t hugetlbfs -o size=4G gave a 0GB filesystem,
size=5G gave a 1GB filesystem etc: there's no point in masking size with
HPAGE_MASK just before shifting its lower bits away, and since HPAGE_MASK is a
UL, that removed all the higher bits of the unsigned long long size.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix printk format warnings:
drivers/block/cciss.c:2000: warning: long long int format, long unsigned int arg (arg 2)
drivers/block/cciss.c:2035: warning: long long int format, long unsigned int arg (arg 2)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix printk format warning:
drivers/misc/ioc4.c:213: warning: long long int format, u64 arg (arg 3)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Brent Casavant <bcasavan@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If __vmalloc is called to allocate memory with GFP_ATOMIC in atomic
context, the chain of calls results in __get_vm_area_node allocating memory
for vm_struct with GFP_KERNEL, causing the 'sleeping from invalid context'
warning. This patch fixes it by passing the gfp flags along so
__get_vm_area_node allocates memory for vm_struct with the same flags.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
blkdev_open() calls bc_acquire() to get a struct block_device. Since
bc_acquire() may return NULL when system is out of memory an appropriate
check is required.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add __GFP_NOWARN flag to calling of __alloc_pages() in
__kmalloc_section_memmap(). It can reduce noisy failure message.
In ia64, section size is 1 GB, this means that order 8 pages are necessary
for each section's memmap. It is often very hard requirement under heavy
memory pressure as you know. So, __alloc_pages() gives up allocation and
shows many noisy stack traces which means no page for each sections.
(Current my environment shows 32 times of stack trace....)
But, __kmalloc_section_memmap() calls vmalloc() after failure of it, and it
can succeed allocation of memmap. So, its stack trace warning becomes just
noisy. I suppose it shouldn't be shown.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/md/raid1.c:1479: warning: long long unsigned int format, long unsigned int arg (arg 4)
drivers/md/raid10.c:1475: warning: long long unsigned int format, long unsigned int arg (arg 4)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A recent fix which made sure ->degraded was initialised properly exposed a
second bug - ->degraded wasn't been updated when drives failed or were
hot-added.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When "mdadm --grow --size=xxx" is used to resize an array (use more or less of
each device), we check the new siza against the available space in each
device.
We already have that number recorded in rdev->size, so calculating it is
pointless (and wrong in one obscure case).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If save_raid_disk is >= 0, then the device could be a device that is already
in sync that is being re-added. So we need to default this value to -1.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
efi_memory_present_wrapper() parameter start/end is physical address, but
function memory_present parameter is PFN, this patch converts physical
address to PFN.
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When running several fsx's and other filesystem stress tests, we found
cases where an unmapped buffer was still being sent to submit_bh by the
ext3 dirty data journaling code.
I saw this happen in two ways, both related to another thread doing a
truncate which would unmap the buffer in question.
Either we would get into journal_dirty_data with a bh which was already
unmapped (although journal_dirty_data_fn had checked for this earlier, the
state was not locked at that point), or it would get unmapped in the middle
of journal_dirty_data when we dropped locks to call sync_dirty_buffer.
By re-checking for mapped state after we've acquired the bh state lock, we
should avoid these races. If we find a buffer which is no longer mapped,
we essentially ignore it, because journal_unmap_buffer has already decided
that this buffer can go away.
I've also added tracepoints in these two cases, and made a couple other
tracepoint changes that I found useful in debugging this.
Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When running several fsx's and other filesystem stress tests, we found
cases where an unmapped buffer was still being sent to submit_bh by the
ext3 dirty data journaling code.
I saw this happen in two ways, both related to another thread doing a
truncate which would unmap the buffer in question.
Either we would get into journal_dirty_data with a bh which was already
unmapped (although journal_dirty_data_fn had checked for this earlier, the
state was not locked at that point), or it would get unmapped in the middle
of journal_dirty_data when we dropped locks to call sync_dirty_buffer.
By re-checking for mapped state after we've acquired the bh state lock, we
should avoid these races. If we find a buffer which is no longer mapped,
we essentially ignore it, because journal_unmap_buffer has already decided
that this buffer can go away.
I've also added tracepoints in these two cases, and made a couple other
tracepoint changes that I found useful in debugging this.
Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/ext4/resize.c:72: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:76: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:81: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:85: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:89: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:89: warning: long long unsigned int format, __u64 arg (arg 5)
fs/ext4/resize.c:93: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:93: warning: long long unsigned int format, __u64 arg (arg 5)
fs/ext4/resize.c:98: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:103: warning: long long unsigned int format, __u64 arg (arg 4)
fs/ext4/resize.c:109: warning: long long unsigned int format, __u64 arg (arg 4)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If try_to_free_pages / balance_pgdat are called with a gfp_mask specifying
GFP_IO and/or GFP_FS, they will reclaim the requisite number of pages, and the
reset prev_priority to DEF_PRIORITY (or to some other high (ie: unurgent)
value).
However, another reclaimer without those gfp_mask flags set (say, GFP_NOIO)
may still be struggling to reclaim pages. The concurrent overwrite of
zone->prev_priority will cause this GFP_NOIO thread to unexpectedly cease
deactivating mapped pages, thus causing reclaim difficulties.
Fix this is to key the distress calculation not off zone->prev_priority, but
also take into account the local caller's priority by using
min(zone->prev_priority, sc->priority)
Signed-off-by: Martin J. Bligh <mbligh@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The temp_priority field in zone is racy, as we can walk through a reclaim
path, and just before we copy it into prev_priority, it can be overwritten
(say with DEF_PRIORITY) by another reclaimer.
The same bug is contained in both try_to_free_pages and balance_pgdat, but
it is fixed slightly differently. In balance_pgdat, we keep a separate
priority record per zone in a local array. In try_to_free_pages there is
no need to do this, as the priority level is the same for all zones that we
reclaim from.
Impact of this bug is that temp_priority is copied into prev_priority, and
setting this artificially high causes reclaimers to set distress
artificially low. They then fail to reclaim mapped pages, when they are,
in fact, under severe memory pressure (their priority may be as low as 0).
This causes the OOM killer to fire incorrectly.
From: Andrew Morton <akpm@osdl.org>
__zone_reclaim() isn't modifying zone->prev_priority. But zone->prev_priority
is used in the decision whether or not to bring mapped pages onto the inactive
list. Hence there's a risk here that __zone_reclaim() will fail because
zone->prev_priority ir large (ie: low urgency) and lots of mapped pages end up
stuck on the active list.
Fix that up by decreasing (ie making more urgent) zone->prev_priority as
__zone_reclaim() scans the zone's pages.
This bug perhaps explains why ZONE_RECLAIM_PRIORITY was created. It should be
possible to remove that now, and to just start out at DEF_PRIORITY?
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Consolidate page_cache_alloc
- Fix splice: only the pagecache pages and filesystem data need to use
mapping_gfp_mask.
- Fix grab_cache_page_nowait: same as splice, also honour NUMA placement.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The SIGFPE signal should be generated if Division by Zero exception is detected.
Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Akinobu Mita