The last change to improve the scalability moved the actual wake-up out of
the section that is protected by spin_lock(sma->sem_perm.lock).
This means that IN_WAKEUP can be in queue.status even when the spinlock is
acquired by the current task. Thus the same loop that is performed when
queue.status is read without the spinlock acquired must be performed when
the spinlock is acquired.
Thanks to kamezawa.hiroyu@jp.fujitsu.com for noticing lack of the memory
barrier.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16255
[akpm@linux-foundation.org: clean up kerneldoc, checkpatch warning and whitespace]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Luca Tettamanti <kronos.it@gmail.com>
Tested-by: Luca Tettamanti <kronos.it@gmail.com>
Reported-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'shrinker' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev:
xfs: track AGs with reclaimable inodes in per-ag radix tree
xfs: convert inode shrinker to per-filesystem contexts
mm: add context argument to shrinker callback
https://bugzilla.kernel.org/show_bug.cgi?id=16348
When the filesystem grows to a large number of allocation groups,
the summing of recalimable inodes gets expensive. In many cases,
most AGs won't have any reclaimable inodes and so we are wasting CPU
time aggregating over these AGs. This is particularly important for
the inode shrinker that gets called frequently under memory
pressure.
To avoid the overhead, track AGs with reclaimable inodes in the
per-ag radix tree so that we can find all the AGs with reclaimable
inodes via a simple gang tag lookup. This involves setting the tag
when the first reclaimable inode is tracked in the AG, and removing
the tag when the last reclaimable inode is removed from the tree.
Then the summation process becomes a loop walking the radix tree
summing AGs with the reclaim tag set.
This significantly reduces the overhead of scanning - a 6400 AG
filesystea now only uses about 25% of a cpu in kswapd while slab
reclaim progresses instead of being permanently stuck at 100% CPU
and making little progress. Clean filesystems filesystems will see
no overhead and the overhead only increases linearly with the number
of dirty AGs.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Now the shrinker passes us a context, wire up a shrinker context per
filesystem. This allows us to remove the global mount list and the
locking problems that introduced. It also means that a shrinker call
does not need to traverse clean filesystems before finding a
filesystem with reclaimable inodes. This significantly reduces
scanning overhead when lots of filesystems are present.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
1. The BTRFS_IOC_CLONE and BTRFS_IOC_CLONE_RANGE ioctls should check
whether the donor file is append-only before writing to it.
2. The BTRFS_IOC_CLONE_RANGE ioctl appears to have an integer
overflow that allows a user to specify an out-of-bounds range to copy
from the source file (if off + len wraps around). I haven't been able
to successfully exploit this, but I'd imagine that a clever attacker
could use this to read things he shouldn't. Even if it's not
exploitable, it couldn't hurt to be safe.
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
cc: stable@kernel.org
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, pci, mrst: Add extra sanity check in walking the PCI extended cap chain
x86: Fix x2apic preenabled system with kexec
x86: Force HPET readback_cmp for all ATI chipsets
* 'kmemleak' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm:
kmemleak: Add support for NO_BOOTMEM configurations
kmemleak: Annotate false positive in init_section_page_cgroup()
The CLONE and CLONE_RANGE ioctls round up the range of extents being
cloned to the block size when the range to clone extends to the end of file
(this is always the case with CLONE). It was then using that offset when
extending the destination file's i_size. Fix this by not setting i_size
beyond the originally requested ending offset.
This bug was introduced by a22285a6 (2.6.35-rc1).
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
split_leaf was not properly balancing leaves when it was forced to
split a leaf twice. This commit adds an extra push left and right
before forcing the double split in hopes of getting the slot where
we want to insert at either the start or end of the leaf.
If the extra pushes do work, then we are able to avoid splitting twice
and we keep the tree properly balanced.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
With commits 08677214 and 59be5a8e, alloc_bootmem()/free_bootmem() and
friends use the early_res functions for memory management when
NO_BOOTMEM is enabled. This patch adds the kmemleak calls in the
corresponding code paths for bootmem allocations.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
The pointer to the page_cgroup table allocated in
init_section_page_cgroup() is stored in section->page_cgroup as (base -
pfn). Since this value does not point to the beginning or inside the
allocated memory block, kmemleak reports a false positive.
This was reported in bugzilla.kernel.org as #16297.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Adrien Dessemond <adrien.dessemond@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
The length filed in the chsc response block (if valid)
has a value of n*(sizeof(chp_desc))+8 (for the response
block header). When we memcopied from the response block
to the actual descriptor we copied 8 bytes too much.
The bug was not revealed since the descriptor is embedded
in struct channel_path.
Since we only write one descriptor at a time ignore the
length value and use sizeof(*desc).
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The dasd_alias_show function does not return a device reference
in case the device is an alias.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Partition boundary calculation fails for DASD FBA disks under the
following conditions:
- disk is formatted with CMS FORMAT with a blocksize of more than
512 bytes
- all of the disk is reserved to a single CMS file using CMS RESERVE
- the disk is accessed using the DIAG mode of the DASD driver
Under these circumstances, the partition detection code tries to
read the CMS label block containing partition-relevant information
from logical block offset 1, while it is in fact located at physical
block offset 1.
Fix this problem by using the correct CMS label block location
depending on the device type as determined by the DASD SENSE ID
information.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In commit f007ea26, the order of the %es and %ds segment registers
got accidentally swapped, so synthesized 'struct pt_regs' frames
have the two values inverted. It's almost sure that these values
never matter, and that they also never differ. But wrong is wrong.
Signed-off-by: Roland McGrath <roland@redhat.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2: Silence gcc warning in ocfs2_write_zero_page().
jbd2/ocfs2: Fix block checksumming when a buffer is used in several transactions
ocfs2/dlm: Remove BUG_ON from migration in the rare case of a down node
ocfs2: Don't duplicate pages past i_size during CoW.
ocfs2: tighten up strlen() checking
ocfs2: Make xattr reflink work with new local alloc reservation.
ocfs2: make xattr extension work with new local alloc reservation.
ocfs2: Remove the redundant cpu_to_le64.
ocfs2/dlm: don't access beyond bitmap size
ocfs2: No need to zero pages past i_size.
ocfs2: Zero the tail cluster when extending past i_size.
ocfs2: When zero extending, do it by page.
ocfs2: Limit default local alloc size within bitmap range.
ocfs2: Move orphan scan work to ocfs2_wq.
fs/ocfs2/dlm: Add missing spin_unlock
The hibernate issues that got fixed in commit 985b823b91 ("drm/i915:
fix hibernation since i915 self-reclaim fixes") turn out to have been
incomplete. Vefa Bicakci tested lots of hibernate cycles, and without
the __GFP_RECLAIMABLE flag the system eventually fails to resume.
With the flag added, Vefa can apparently hibernate forever (or until he
gets bored running his automated scripts, whichever comes first).
The reclaimable flag was there originally, and was one of the flags that
were dropped (unintentionally) by commit 4bdadb9785 ("drm/i915:
Selectively enable self-reclaim") that introduced all these problems,
but I didn't want to just blindly add back all the flags in commit
985b823b91, and it looked like __GFP_RECLAIM wasn't necessary. It
clearly was.
I still suspect that there is some subtle reason we're missing that
causes the problems, but __GFP_RECLAIMABLE is certainly not wrong to use
in this context, and is what the code historically used. And we have no
idea what the causes the corruption without it.
Reported-and-tested-by: M. Vefa Bicakci <bicave@superonline.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin
Manfred Spraul
Linus Torvalds
Dave Chinner
Dan Rosenberg
Sreedhara DS
Sage Weil
Chris Mason
Catalin Marinas
Sebastian Ott
Stefan Haberland
Peter Oberparleiter
Roland McGrath