If a SIGKILL is sent to a task waiting in __nfs_iocounter_wait,
it will busy-wait or soft lockup in its while loop.
nfs_wait_bit_killable won't sleep, and the loop won't exit on
the error return.
Stop the busy-wait by breaking out of the loop when
nfs_wait_bit_killable returns an error.
Signed-off-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[ kamal: backport to 3.13-stable: context ] Cc: Moritz Mühlenhoff <muehlenhoff@univention.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On x86_64, kernel text mappings are mapped read-only with CONFIG_DEBUG_RODATA.
In that case, KVM will fail to patch VMCALL instructions to VMMCALL
as required on AMD processors.
The failure mode is currently a divide-by-zero exception, which obviously
is a KVM bug that has to be fixed. However, picking the right instruction
between VMCALL and VMMCALL will be faster and will help if you cannot upgrade
the hypervisor.
Reported-by: Chris Webb <chris@arachsys.com> Tested-by: Chris Webb <chris@arachsys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
batman tries to search dev->iflink to check if it's a batman interface,
but ->iflink could be 0, which is not a valid ifindex. It should just
avoid iflink == 0 case.
Reported-by: Jet Chen <jet.chen@intel.com> Tested-by: Jet Chen <jet.chen@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Antonio Quartulli <antonio@open-mesh.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A leftover lock on the list is surely a sign of a problem of some sort,
but it's not necessarily a reason to panic the box. Instead, just log a
warning with some info about the lock, and then delete it like we would
any other lock.
In the event that the filesystem declares a ->lock f_op, we may end up
leaking something, but that's generally preferable to an immediate
panic.
Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: Markus Blank-Burian <burian@muenster.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some radeon ASICs don't support all 64 address bits of MSIs despite
advertising support for 64-bit MSIs in their configuration space.
This breaks on systems such as IBM POWER7/8, where 64-bit MSIs can
be assigned with some of the high address bits set.
This makes use of the newly introduced "no_64bit_msi" flag in structure
pci_dev to allow the MSI allocation code to fallback to 32-bit MSIs
on those adapters.
Adding Alex's review tag. Patch to the driver is identical to the
reviewed one, I dropped the arch/powerpc hunk rewrote the subject
and cset comment.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In some cases, the fcoe_rx_list may contains multiple instances
of the same skb (the so called "shared skbs").
the bnx2fc_l2_rcv thread is a loop that extracts a skb from the list,
modifies (and destroys) its content and then proceed to the next one.
The problem is that if the skb is shared, the remaining instances will
be corrupted.
The solution is to use skb_share_check() before adding the skb to the
fcoe_rx_list.
ping_lookup() may return a wrong sock if sk_buff's and sock's protocols
dont' match. For example, sk_buff's protocol is ETH_P_IPV6, but sock's
sk_family is AF_INET, in that case, if sk->sk_bound_dev_if is zero, a wrong
sock will be returned.
the fix is to "continue" the searching, if no matching, return NULL.
Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: netdev@vger.kernel.org Signed-off-by: Jane Zhou <a17711@motorola.com> Signed-off-by: Yiwei Zhao <gbjc64@motorola.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the DRC cache pruner will stop scanning the list when it
hits an entry that is RC_INPROG. It's possible however for a call to
take a *very* long time. In that case, we don't want it to block other
entries from being pruned if they are expired or we need to trim the
cache to get back under the limit.
Fix the DRC cache pruner to just ignore RC_INPROG entries.
Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Cc: Joseph Salisbury <joseph.salisbury@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Even when security labels are disabled we support at least the same
attributes as v4.1.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Panic happened because we eat 4 bytes of skb headroom on each
(re)transmission when sending frame without the payload and the header
length not being multiple of 4 (i.e. QoS header has 26 bytes). On such
case because paylad_aling=2 is bigger than header_align=0 we increase
header_align by 4 bytes. To prevent that we could change the check to:
if (payload_length && payload_align > header_align)
header_align += 4;
but not aligning payload at all is more effective and alignment is not
really needed by H/W (that has been tested on OpenWrt project for few
years now).
Reported-and-tested-by: Antti S. Lankila <alankila@bel.fi> Debugged-by: Antti S. Lankila <alankila@bel.fi> Reported-by: Henrik Asp <solenskiner@gmail.com>
Originally-From: Helmut Schaa <helmut.schaa@googlemail.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel Multi-Flex LUNs choke on REPORT SUPPORTED OPERATION CODES
resulting in sd_mod hanging for several minutes on startup.
The issue was introduced with WRITE SAME discovery heuristics.
Fixes: 5db44863b6eb ("[SCSI] sd: Implement support for WRITE SAME") Signed-off-by: Christian Sünkenberg <christian.suenkenberg@hfg-karlsruhe.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch addresses a bug where individual vhost-scsi configfs endpoint
groups can be removed from below while active exports to QEMU userspace
still exist, resulting in an OOPs.
It adds a configfs_depend_item() in vhost_scsi_set_endpoint() to obtain
an explicit dependency on se_tpg->tpg_group in order to prevent individual
vhost-scsi WWPN endpoints from being released via normal configfs methods
while an QEMU ioctl reference still exists.
Also, add matching configfs_undepend_item() in vhost_scsi_clear_endpoint()
to release the dependency, once QEMU's reference to the individual group
at /sys/kernel/config/target/vhost/$WWPN/$TPGT is released.
(Fix up vhost_scsi_clear_endpoint() error path - DanC)
Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An IOCTL call that calls spi_setup() and then dw_spi_setup() will
overwrite the persisted last transfer speed. On each transfer, the
SPI speed is compared to the last transfer speed to determine if the
clock divider registers need to be updated (did the speed change?).
This bug was observed with the spidev driver using spi-config to
update the max transfer speed.
This fix: Don't overwrite the persisted last transaction clock speed
when updating the SPI parameters in dw_spi_setup(). On the next
transaction, the new speed won't match the persisted last speed
and the hardware registers will be updated.
On initialization, the persisted last transaction clock
speed will be 0 but will be updated after the first SPI
transaction.
Move zeroed clock divider check into clock change test because
chip->clk_div is zero on startup and would cause a divide-by-zero
error. The calculation was wrong as well (can't support odd #).
Reported-by: Vlastimil Setka <setka@vsis.cz> Signed-off-by: Vlastimil Setka <setka@vsis.cz> Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch explicitly disables TX completion interrupt coalescing logic
in isert_put_response() and isert_put_datain() that was originally added
as an efficiency optimization in commit 95b60f07.
It has been reported that this change can trigger ABORT_TASK timeouts
under certain small block workloads, where disabling coalescing was
required for stability. According to Sagi, this doesn't impact
overall performance, so go ahead and disable it for now.
Reported-by: Moussa Ba <moussaba@micron.com> Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case the discovery session is carried over iser, we can't
access the assumed network portal since the default portal is
used. In this case we don't really need to allocate the fastreg
pool, just prepare to the text pdu that will follow.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Reported-by: Alex Tabachnik <alext@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If an initiator sends a zero-length command (e.g. TEST UNIT READY) but
sets the transfer direction in the transport layer to indicate a
data-out phase, we still shouldn't try to transfer data. At best it's
a NOP, and depending on the transport, we might crash on an
uninitialized sg list.
Reported-by: Craig Watson <craig.watson@vanguard-rugged.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is not guaranteed to that srp_sq_size is supported
by the HCA. So if we failed to create the QP with ENOMEM,
try with a smaller srp_sq_size. Keep it up until we hit
MIN_SRPT_SQ_SIZE, then fail the connection.
Reported-by: Mark Lehrer <lehrer@gmail.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The xpad wireless endpoint is not a bulk endpoint on my devices, but
rather an interrupt one, so the USB core complains when it is submitted.
I'm guessing that the author really did mean that this should be an
interrupt urb, but as there are a zillion different xpad devices out
there, let's cover out bases and handle both bulk and interrupt
endpoints just as easily.
The LEN2006 Synaptics touchpad (as found in Thinkpad E540) returns wrong
min max values.
touchpad-edge-detector output:
> Touchpad SynPS/2 Synaptics TouchPad on /dev/input/event6
> Move one finger around the touchpad to detect the actual edges
> Kernel says: x [1472..5674], y [1408..4684]
> Touchpad sends: x [1264..5675], y [1171..4688]
We cannot restart cacheflush safely if a process provides user-defined
signal handler and signal is pending. In this case -EINTR is returned
and it is expected that process re-invokes syscall. However, there are
a few problems with that:
* looks like nobody bothers checking return value from cacheflush
* but if it did, we don't provide the restart address for that, so the
process has to use the same range again
* ...and again, what might lead to looping forever
So, remove cacheflush restarting code and terminate cache flushing
as early as fatal signal is pending.
Reported-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Under extremely rare conditions, in an MPCore node consisting of at
least 3 CPUs, two CPUs trying to perform a STREX to data on the same
shared cache line can enter a livelock situation.
This patch enables the HW mechanism that overcomes the bug. This fixes
the incorrect setup of the STREX backoff delay bit due to a wrong
description in the specification.
Note that enabling the STREX backoff delay mechanism is done by
leaving the bit *cleared*, while the bit was currently being set by
the proc-v7.S code.
[Thomas: adapt to latest mainline, slightly reword the commit log, add
stable markers.]
Fixes: de4901933f6d ("arm: mm: Add support for PJ4B cpu and init routines") Signed-off-by: Nadav Haklai <nadavh@marvell.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Acked-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to the manuals I have, XScale auxiliary register should be
reached with opc_2 = 1 instead of crn = 1. cpu_xscale_proc_init
correctly uses c1, c0, 1 arguments, but cpu_xscale_do_suspend and
cpu_xscale_do_resume use c1, c1, 0. Correct suspend/resume functions to
also use c1, c0, 1.
The issue was primarily noticed thanks to qemu reporing "unsupported
instruction" on the pxa suspend path. Confirmed in PXA210/250 and PXA255
XScale Core manuals and in PXA270 and PXA320 Developers Guides.
Harware tested by me on tosa (pxa255). Robert confirmed on pxa270 board.
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
a9ecdc0fdc54 ("of/irq: Fix lookup to use 'interrupts-extended' property
first") updated the description to say that:
- Both 'interrupts' and 'interrupts-extended' may be present
- Software should prefer 'interrupts-extended'
- Software that doesn't comprehend 'interrupts-extended' may use
'interrupts'
But there is still a paragraph at the end that prohibits having both and
says 'interrupts' should be preferred.
Remove the contradictory text.
Fixes: a9ecdc0fdc54 ("of/irq: Fix lookup to use 'interrupts-extended' property first") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Brian Norris <computersforpeace@gmail.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Markus reported that when shutting down mysqld (with AIO support,
on a ext3 formatted Harddrive) leads to a negative number of dirty pages
(underrun to the counter). The negative number results in a drastic reduction
of the write performance because the page cache is not used, because the kernel
thinks it is still 2 ^ 32 dirty pages open.
Add a warn trace in __dec_zone_state will catch this easily:
[ 21.341632] ------------[ cut here ]------------
[ 21.346294] WARNING: CPU: 0 PID: 309 at include/linux/vmstat.h:242
cancel_dirty_page+0x164/0x224()
[ 21.355296] Modules linked in: wutbox_cp sata_mv
[ 21.359968] CPU: 0 PID: 309 Comm: kworker/0:1 Not tainted 3.14.21-WuT #80
[ 21.366793] Workqueue: events free_ioctx
[ 21.370760] [<c0016a64>] (unwind_backtrace) from [<c0012f88>]
(show_stack+0x20/0x24)
[ 21.378562] [<c0012f88>] (show_stack) from [<c03f8ccc>]
(dump_stack+0x24/0x28)
[ 21.385840] [<c03f8ccc>] (dump_stack) from [<c0023ae4>]
(warn_slowpath_common+0x84/0x9c)
[ 21.393976] [<c0023ae4>] (warn_slowpath_common) from [<c0023bb8>]
(warn_slowpath_null+0x2c/0x34)
[ 21.402800] [<c0023bb8>] (warn_slowpath_null) from [<c00c0688>]
(cancel_dirty_page+0x164/0x224)
[ 21.411524] [<c00c0688>] (cancel_dirty_page) from [<c00c080c>]
(truncate_inode_page+0x8c/0x158)
[ 21.420272] [<c00c080c>] (truncate_inode_page) from [<c00c0a94>]
(truncate_inode_pages_range+0x11c/0x53c)
[ 21.429890] [<c00c0a94>] (truncate_inode_pages_range) from
[<c00c0f6c>] (truncate_pagecache+0x88/0xac)
[ 21.439252] [<c00c0f6c>] (truncate_pagecache) from [<c00c0fec>]
(truncate_setsize+0x5c/0x74)
[ 21.447731] [<c00c0fec>] (truncate_setsize) from [<c013b3a8>]
(put_aio_ring_file.isra.14+0x34/0x90)
[ 21.456826] [<c013b3a8>] (put_aio_ring_file.isra.14) from
[<c013b424>] (aio_free_ring+0x20/0xcc)
[ 21.465660] [<c013b424>] (aio_free_ring) from [<c013b4f4>]
(free_ioctx+0x24/0x44)
[ 21.473190] [<c013b4f4>] (free_ioctx) from [<c003d8d8>]
(process_one_work+0x134/0x47c)
[ 21.481132] [<c003d8d8>] (process_one_work) from [<c003e988>]
(worker_thread+0x130/0x414)
[ 21.489350] [<c003e988>] (worker_thread) from [<c00448ac>]
(kthread+0xd4/0xec)
[ 21.496621] [<c00448ac>] (kthread) from [<c000ec18>]
(ret_from_fork+0x14/0x20)
[ 21.503884] ---[ end trace 79c4bf42c038c9a1 ]---
The cause is that we set the aio ring file pages as *DIRTY* via SetPageDirty
(bypasses the VFS dirty pages increment) when init, and aio fs uses
*default_backing_dev_info* as the backing dev, which does not disable
the dirty pages accounting capability.
So truncating aio ring file will contribute to accounting dirty pages (VFS
dirty pages decrement), then error occurs.
The original goal is keeping these pages in memory (can not be reclaimed
or swapped) in life-time via marking it dirty. But thinking more, we have
already pinned pages via elevating the page's refcount, which can already
achieve the goal, so the SetPageDirty seems unnecessary.
In order to fix the issue, using the __set_page_dirty_no_writeback instead
of the nop .set_page_dirty, and dropped the SetPageDirty (don't manually
set the dirty flags, don't disable set_page_dirty(), rely on default behaviour).
With the above change, the dirty pages accounting can work well. But as we
known, aio fs is an anonymous one, which should never cause any real write-back,
we can ignore the dirty pages (write back) accounting by disabling the dirty
pages (write back) accounting capability. So we introduce an aio private
backing dev info (disabled the ACCT_DIRTY/WRITEBACK/ACCT_WB capabilities) to
replace the default one.
Reported-by: Markus Königshaus <m.koenigshaus@wut.de> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a USB control message delay quirk for a few specific Marantz/Denon
devices. Without the delay the DACs will not work properly and produces the
following type of messages:
Nov 15 10:09:21 orwell kernel: [ 91.342880] usb 3-13: clock source 41 is not valid, cannot use
Nov 15 10:09:21 orwell kernel: [ 91.343775] usb 3-13: clock source 41 is not valid, cannot use
There are likely other Marantz/Denon devices using the same USB module which exhibit the
same problems. But as this cannot be verified I limited the patch to the devices
I could test.
The following two devices are covered by this path:
- Marantz SA-14S1
- Marantz HD-DAC1
When system is being suspended, if host device is not allowed to do wakeup,
xhci_suspend() needs to clear all root port wake on bits. Otherwise, some
platforms may generate spurious wakeup, even if PCI PME# is disabled.
The initial commit ff8cbf250b44 ("xhci: clear root port wake on bits"),
which also got into stable, turned out to not work correctly and had to
be reverted, and is now rewritten.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Suggested-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Alan Stern <stern@rowland.harvard.edu>
[Mathias Nyman: reword commit message] Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A halted endpoint ring must first be reset, then move the ring
dequeue pointer past the problematic TRB. If we start the ring too
early after reset, but before moving the dequeue pointer we
will end up executing the same problematic TRB again.
As we always issue a set transfer dequeue command after a reset
endpoint command we can skip starting endpoint rings at reset endpoint
command completion.
Without this fix we end up trying to handle the same faulty TD for
contol endpoints. causing timeout, and failing testusb ctrl_out write
tests.
Fixes: e9df17e (USB: xhci: Correct assumptions about number of rings per endpoint.) Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix handling of TTY error flags, which are not bitmasks and must
specifically not be ORed together as this prevents the line discipline
from recognising them.
Also insert null characters when reporting overrun errors as these are
not associated with the received character.
We have a historical hack that treats missing ranges properties as the
equivalent of an empty one. This is needed for ancient PowerMac "bad"
device-trees, and shouldn't be enabled for any other PowerPC platform,
otherwise we get some nasty layout of devices in sysfs or even
duplication when a set of otherwise identically named devices is
created multiple times under a different parent node with no ranges
property.
This fix is needed for the PowerNV i2c busses to be exposed properly
and will fix a number of other embedded cases.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on the reference clock, which could be 25MHz or 40MHz,
AR_RTC_DERIVED_CLK is programmed differently for AR9340 and AR9550.
But, when a chip reset is done, processing the initvals
sets the register back to the default value.
Fix this by moving the code in ath9k_hw_init_pll() to
ar9003_hw_override_ini(). Also, do this override for AR9531.
Signed-off-by: Miaoqing Pan <miaoqing@qca.qualcomm.com> Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DPCM can update the FE/BE connection states totally asynchronously
from the FE's PCM state. Most of FE/BE state changes are protected by
mutex, so that they won't race, but there are still some actions that
are uncovered. For example, suppose to switch a BE while a FE's
stream is running. This would call soc_dpcm_runtime_update(), which
sets FE's runtime_update flag, then sets up and starts BEs, and clears
FE's runtime_update flag again.
When a device emits XRUN during this operation, the PCM core triggers
snd_pcm_stop(XRUN). Since the trigger action is an atomic ops, this
isn't blocked by the mutex, thus it kicks off DPCM's trigger action.
It eventually updates and clears FE's runtime_update flag while
soc_dpcm_runtime_update() is running concurrently, and it results in
confusion.
Usually, for avoiding such a race, we take a lock. There is a PCM
stream lock for that purpose. However, as already mentioned, the
trigger action is atomic, and we can't take the lock for the whole
soc_dpcm_runtime_update() or other operations that include the lengthy
jobs like hw_params or prepare.
This patch provides an alternative solution. This adds a way to defer
the conflicting trigger callback to be executed at the end of FE/BE
state changes. For doing it, two things are introduced:
- Each runtime_update state change of FEs is protected via PCM stream
lock.
- The FE's trigger callback checks the runtime_update flag. If it's
not set, the trigger action is executed there. If set, mark the
pending trigger action and returns immediately.
- At the exit of runtime_update state change, it checks whether the
pending trigger is present. If yes, it executes the trigger action
at this point.
Reported-and-tested-by: Qiao Zhou <zhouqiao@marvell.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should not free any buffers associated with writing out coefficients
to the DSP until all the async writes have completed. This patch updates
the out of memory path when allocating a new buffer to include a call to
regmap_async_complete.
Reported-by: JS Park <aitdark.park@samsung.com> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a max_send_sge=2 minimum in isert_conn_setup_qp()
to ensure outgoing control PDU responses with tx_desc->num_sge=2
are able to function correctly.
This addresses a bug with RDMA hardware using dev_attr.max_sge=3,
that in the original code with the ConnectX-2 work-around would
result in isert_conn->max_sge=1 being negotiated.
Originally reported by Chris with ocrdma driver.
Reported-by: Chris Moore <Chris.Moore@emulex.com> Tested-by: Chris Moore <Chris.Moore@emulex.com> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
isert has an issue of trying to create a CQ with more CQEs than are
supported by the hardware, that currently results in failures during
isert_device creation during first session login.
This is the isert version of the patch that Minh Tran submitted for
iser, and is simple a workaround required to function with existing
ocrdma hardware.
Signed-off-by: Chris Moore <chris.moore@emulex.com> Reviewied-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This can be set by quirks/drivers to be used by the architecture code
that assigns the MSI addresses.
We additionally add verification in the core MSI code that the values
assigned by the architecture do satisfy the limitation in order to fail
gracefully if they don't (ie. the arch hasn't been updated to deal with
that quirk yet).
In this kernel, unsigned long is 32 bits and dma_addr_t is 64 bits.
Previously we used "unsigned long" to hold the bridge window address. But
this is a bus address, so we should use dma_addr_t instead.
Use dma_addr_t to hold the bridge window base and limit.
The question of whether the CPU can actually *address* the window is
separate and depends on what the physical address space of the CPU is and
whether the host bridge does any address translation.
[bhelgaas: fix "shift count > width of type", changelog, stable tag] Fixes: d56dbf5bab8c ("PCI: Allocate 64-bit BARs above 4G when possible") Link: https://bugzilla.kernel.org/show_bug.cgi?id=88131 Reported-by: Aaron Ma <mapengyu@gmail.com> Tested-by: Aaron Ma <mapengyu@gmail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This fixes an old regression introduced by commit b0d0d915 (ipx: remove the BKL).
When a recvmsg syscall blocks waiting for new data, no data can be sent on the
same socket with sendmsg because ipx_recvmsg() sleeps with the socket locked.
This breaks mars-nwe (NetWare emulator):
- the ncpserv process reads the request using recvmsg
- ncpserv forks and spawns nwconn
- ncpserv calls a (blocking) recvmsg and waits for new requests
- nwconn deadlocks in sendmsg on the same socket
Commit b0d0d915 has simply replaced BKL locking with
lock_sock/release_sock. Unlike now, BKL got unlocked while
sleeping, so a blocking recvmsg did not block a concurrent
sendmsg.
Only keep the socket locked while actually working with the socket data and
release it prior to calling skb_recv_datagram().
Signed-off-by: Jiri Bohac <jbohac@suse.cz> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().
Fix this by memset(0)'ing the union before.
Cc: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 6fde8f037e60 ("bonding: fix locking in
bond_loadbalance_arp_mon()") we can have a stale bond carrier state and
stale curr_active_slave when using arp monitoring in loadbalance modes. The
reason is that in bond_loadbalance_arp_mon() we can't have
do_failover == true but slave_state_changed == false, whenever do_failover
is true then slave_state_changed is also true. Then the following piece
from bond_loadbalance_arp_mon():
if (slave_state_changed) {
bond_slave_state_change(bond);
if (BOND_MODE(bond) == BOND_MODE_XOR)
bond_update_slave_arr(bond, NULL);
} else if (do_failover) {
block_netpoll_tx();
bond_select_active_slave(bond);
unblock_netpoll_tx();
}
will execute only the first branch, always and regardless of do_failover.
Since these two events aren't related in such way, we need to decouple and
consider them separately.
For example this issue could lead to the following result:
Bonding Mode: load balancing (round-robin)
*MII Status: down*
MII Polling Interval (ms): 0
Up Delay (ms): 0
Down Delay (ms): 0
ARP Polling Interval (ms): 100
ARP IP target/s (n.n.n.n form): 192.168.9.2
Since some interfaces are up, then the status of the bond should also be
up, but it will never change unless something invokes bond_set_carrier()
(i.e. enslave, bond_select_active_slave etc). Now, if I force the
calling of bond_select_active_slave via for example changing
primary_reselect (it can change in any mode), then the MII status goes to
"up" because it calls bond_select_active_slave() which should've been done
from bond_loadbalance_arp_mon() itself.
CC: Veaceslav Falico <vfalico@gmail.com> CC: Jay Vosburgh <j.vosburgh@gmail.com> CC: Andy Gospodarek <andy@greyhouse.net> CC: Ding Tianhong <dingtianhong@huawei.com> Fixes: 6fde8f037e60 ("bonding: fix locking in bond_loadbalance_arp_mon()") Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Acked-by: Veaceslav Falico <vfalico@gmail.com> Acked-by: Andy Gospodarek <gospo@cumulusnetworks.com> Acked-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Added the USB VID/PID for the HP lt4112 LTE/HSPA+ Gobi 4G Modem (Huawei me906e)
Signed-off-by: Martin Hauke <mardnh@gmx.de> Acked-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case of any failure ieee802154fake_probe() just calls unregister_netdev().
But it does not look safe to unregister netdevice before it was registered.
The patch implements straightforward resource deallocation in case of
failure in ieee802154fake_probe().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying to add an unreachable route incorrectly returns -ESRCH if
if custom FIB rules are present:
[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: Network is unreachable
[root@localhost ~]# ip rule add to 55.66.77.88 table 200
[root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4
RTNETLINK answers: No such process
[root@localhost ~]#
Commit 83886b6b636173b206f475929e58fac75c6f2446 ("[NET]: Change "not found"
return value for rule lookup") changed fib_rules_lookup()
to use -ESRCH as a "not found" code internally, but for user space it
should be translated into -ENETUNREACH. Handle the translation centrally in
ipv4-specific fib_lookup(), leaving the DECnet case alone.
On a related note, commit b7a71b51ee37d919e4098cd961d59a883fd272d8
("ipv4: removed redundant conditional") removed a similar translation from
ip_route_input_slow() prematurely AIUI.
Fixes: b7a71b51ee37 ("ipv4: removed redundant conditional") Signed-off-by: Panu Matilainen <pmatilai@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There could be a signed overflow in the following code.
The expression, (32-logmask) is comprised between 0 and 31 included.
It may be equal to 31.
In such a case the left shift will produce a signed integer overflow.
According to the C99 Standard, this is an undefined behavior.
A simple fix is to replace the signed int 1 with the unsigned int 1U.
Signed-off-by: Vincent BENAYOUN <vincent.benayoun@trust-in-soft.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are reading the memory location, so we have to have a memory
constraint in there purely for the sake of showing the data flow
to the compiler.
Reported-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns. I suspect that this is a mistake and that
the code only works because int3 is paranoid.
Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
When building with the Gold linker, the .bss and .brk areas of vmlinux
are shown as consecutive instead of having the same file offset. Allow
for either state, as long as things add up correctly.
Fixes: e6023367d779 ("x86, kaslr: Prevent .bss from overlaping initrd") Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Junjie Mao <eternal.n08@gmail.com> Link: http://lkml.kernel.org/r/20141118001604.GA25045@www.outflux.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When setting up permissions on kernel memory at boot, the end of the
PMD that was split from bss remained executable. It should be NX like
the rest. This performs a PMD alignment instead of a PAGE alignment to
get the correct span of memory.
[ tglx: Changed it to roundup(_brk_end, PMD_SIZE) and added a comment.
We really should unmap the reminder along with the holes
caused by init,initdata etc. but thats a different issue ]
Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/20141114194737.GA3091@www.outflux.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
__setup() is designed to match options that take arguments, like
"foo=bar" where you would have:
__setup("foo", x86_foo_func...);
The problem is that "noxsave" actually _matches_ "noxsaves" in
the same way that "foo" matches "foo=bar". If you boot an old
kernel that does not know about "noxsaves" with "noxsaves" on the
command line, it will interpret the argument as "noxsave", which
is not what you want at all.
This makes the "noxsave" handler only return success when it finds
an *exact* match.
[ tglx: We really need to make __setup() more robust. ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20141111220133.FE053984@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's possible for iretq to userspace to fail. This can happen because
of a bad CS, SS, or RIP.
Historically, we've handled it by fixing up an exception from iretq to
land at bad_iret, which pretends that the failed iret frame was really
the hardware part of #GP(0) from userspace. To make this work, there's
an extra fixup to fudge the gs base into a usable state.
This is suboptimal because it loses the original exception. It's also
buggy because there's no guarantee that we were on the kernel stack to
begin with. For example, if the failing iret happened on return from an
NMI, then we'll end up executing general_protection on the NMI stack.
This is bad for several reasons, the most immediate of which is that
general_protection, as a non-paranoid idtentry, will try to deliver
signals and/or schedule from the wrong stack.
This patch throws out bad_iret entirely. As a replacement, it augments
the existing swapgs fudge into a full-blown iret fixup, mostly written
in C. It's should be clearer and more correct.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a 32-bit kernel, this has no effect, since there are no IST stacks.
On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code. The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.
This fixes a bug in which the espfix64 code mishandles a stack segment
violation.
This saves 4k of memory per CPU and a tiny bit of code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If SERIAL_8250 is compiled as a module, the platform specific setup
for Loongson will be a module too, and it will not work very well.
At least on Loongson 3 it will trigger a build failure,
since loongson_sysconf is not exported to modules.
Fix by making the platform specific serial code always built-in.
For the MIGRATE_RESERVE pages, it is useful when they do not get
misplaced on free_list of other migratetype, otherwise they might get
allocated prematurely and e.g. fragment the MIGRATE_RESEVE pageblocks.
While this cannot be avoided completely when allocating new
MIGRATE_RESERVE pageblocks in min_free_kbytes sysctl handler, we should
prevent the misplacement where possible.
Currently, it is possible for the misplacement to happen when a
MIGRATE_RESERVE page is allocated on pcplist through rmqueue_bulk() as a
fallback for other desired migratetype, and then later freed back
through free_pcppages_bulk() without being actually used. This happens
because free_pcppages_bulk() uses get_freepage_migratetype() to choose
the free_list, and rmqueue_bulk() calls set_freepage_migratetype() with
the *desired* migratetype and not the page's original MIGRATE_RESERVE
migratetype.
This patch fixes the problem by moving the call to
set_freepage_migratetype() from rmqueue_bulk() down to
__rmqueue_smallest() and __rmqueue_fallback() where the actual page's
migratetype (e.g. from which free_list the page is taken from) is used.
Note that this migratetype might be different from the pageblock's
migratetype due to freepage stealing decisions. This is OK, as page
stealing never uses MIGRATE_RESERVE as a fallback, and also takes care
to leave all MIGRATE_CMA pages on the correct freelist.
Therefore, as an additional benefit, the call to
get_pageblock_migratetype() from rmqueue_bulk() when CMA is enabled, can
be removed completely. This relies on the fact that MIGRATE_CMA
pageblocks are created only during system init, and the above. The
related is_migrate_isolate() check is also unnecessary, as memory
isolation has other ways to move pages between freelists, and drain pcp
lists containing pages that should be isolated. The buffered_rmqueue()
can also benefit from calling get_freepage_migratetype() instead of
get_pageblock_migratetype().
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Suggested-by: Mel Gorman <mgorman@suse.de> Acked-by: Minchan Kim <minchan@kernel.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: "Wang, Yalin" <Yalin.Wang@sonymobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit "mm: vmscan: obey proportional scanning requirements for kswapd"
ensured that file/anon lists were scanned proportionally for reclaim from
kswapd but ignored it for direct reclaim. The intent was to minimse
direct reclaim latency but Yuanhan Liu pointer out that it substitutes one
long stall for many small stalls and distorts aging for normal workloads
like streaming readers/writers. Hugh Dickins pointed out that a
side-effect of the same commit was that when one LRU list dropped to zero
that the entirety of the other list was shrunk leading to excessive
reclaim in memcgs. This patch scans the file/anon lists proportionally
for direct reclaim to similarly age page whether reclaimed by kswapd or
direct reclaim but takes care to abort reclaim if one LRU drops to zero
after reclaiming the requested number of pages.
Based on ext4 and using the Intel VM scalability test
3.15.0-rc5 3.15.0-rc5
shrinker proportion
Unit lru-file-readonce elapsed 5.3500 ( 0.00%) 5.4200 ( -1.31%)
Unit lru-file-readonce time_range 0.2700 ( 0.00%) 0.1400 ( 48.15%)
Unit lru-file-readonce time_stddv 0.1148 ( 0.00%) 0.0536 ( 53.33%)
Unit lru-file-readtwice elapsed 8.1700 ( 0.00%) 8.1700 ( 0.00%)
Unit lru-file-readtwice time_range 0.4300 ( 0.00%) 0.2300 ( 46.51%)
Unit lru-file-readtwice time_stddv 0.1650 ( 0.00%) 0.0971 ( 41.16%)
The test cases are running multiple dd instances reading sparse files. The results are within
the noise for the small test machine. The impact of the patch is more noticable from the vmstats
3.15.0-rc5 3.15.0-rc5
shrinker proportion
Minor Faults 35154 36784
Major Faults 611 1305
Swap Ins 394 1651
Swap Outs 4394 5891
Allocation stalls 118616 44781
Direct pages scanned 49351714602313
Kswapd pages scanned 1592129216258483
Kswapd pages reclaimed 1591330116248305
Direct pages reclaimed 49333684601133
Kswapd efficiency 99% 99%
Kswapd velocity 670088.047 682555.961
Direct efficiency 99% 99%
Direct velocity 207709.217 193212.133
Percentage direct scans 23% 22%
Page writes by reclaim 4858.000 6232.000
Page writes file 464 341
Page writes anon 4394 5891
Note that there are fewer allocation stalls even though the amount
of direct reclaim scanning is very approximately the same.
Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We remove the call to grab_super_passive in call to super_cache_count.
This becomes a scalability bottleneck as multiple threads are trying to do
memory reclamation, e.g. when we are doing large amount of file read and
page cache is under pressure. The cached objects quickly got reclaimed
down to 0 and we are aborting the cache_scan() reclaim. But counting
creates a log jam acquiring the sb_lock.
We are holding the shrinker_rwsem which ensures the safety of call to
list_lru_count_node() and s_op->nr_cached_objects. The shrinker is
unregistered now before ->kill_sb() so the operation is safe when we are
doing unmount.
The impact will depend heavily on the machine and the workload but for a
small machine using postmark tuned to use 4xRAM size the results were
This series is aimed at regressions noticed during reclaim activity. The
first two patches are shrinker patches that were posted ages ago but never
merged for reasons that are unclear to me. I'm posting them again to see
if there was a reason they were dropped or if they just got lost. Dave?
Time? The last patch adjusts proportional reclaim. Yuanhan Liu, can you
retest the vm scalability test cases on a larger machine? Hugh, does this
work for you on the memcg test cases?
Based on ext4, I get the following results but unfortunately my larger
test machines are all unavailable so this is based on a relatively small
machine.
stutter (times mmap latency during large amounts of IO)
3.15.0-rc5 3.15.0-rc5
vanilla proportion-v1r4
Unit >5ms Delays 80252.0000 ( 0.00%) 81523.0000 ( -1.58%)
Unit Mmap min 8.2118 ( 0.00%) 8.3206 ( -1.33%)
Unit Mmap mean 17.4614 ( 0.00%) 17.2868 ( 1.00%)
Unit Mmap stddev 24.9059 ( 0.00%) 34.6771 (-39.23%)
Unit Mmap max 2811.6433 ( 0.00%) 2645.1398 ( 5.92%)
Unit Mmap 90% 20.5098 ( 0.00%) 18.3105 ( 10.72%)
Unit Mmap 93% 22.9180 ( 0.00%) 20.1751 ( 11.97%)
Unit Mmap 95% 25.2114 ( 0.00%) 22.4988 ( 10.76%)
Unit Mmap 99% 46.1430 ( 0.00%) 43.5952 ( 5.52%)
Unit Ideal Tput 85.2623 ( 0.00%) 78.8906 ( 7.47%)
Unit Tput min 44.0666 ( 0.00%) 43.9609 ( 0.24%)
Unit Tput mean 45.5646 ( 0.00%) 45.2009 ( 0.80%)
Unit Tput stddev 0.9318 ( 0.00%) 1.1084 (-18.95%)
Unit Tput max 46.7375 ( 0.00%) 46.7539 ( -0.04%)
This patch (of 3):
We will like to unregister the sb shrinker before ->kill_sb(). This will
allow cached objects to be counted without call to grab_super_passive() to
update ref count on sb. We want to avoid locking during memory
reclamation especially when we are skipping the memory reclaim when we are
out of cached objects.
This is safe because grab_super_passive does a try-lock on the
sb->s_umount now, and so if we are in the unmount process, it won't ever
block. That means what used to be a deadlock and races we were avoiding
by using grab_super_passive() is now:
970 if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
971 PF_MEMALLOC))
I did not respond at the time, because a glance at the PageDirty block
in shrink_page_list() quickly shows that this is impossible: we don't do
writeback on file pages (other than tmpfs) from direct reclaim nowadays.
Dave was hallucinating, but it would have been disrespectful to say so.
However, my own /var/log/messages now shows similar complaints
WARNING: CPU: 1 PID: 28814 at fs/ext4/inode.c:1881 ext4_writepage+0xa7/0x38b()
WARNING: CPU: 0 PID: 27347 at fs/ext4/inode.c:1764 ext4_writepage+0xa7/0x38b()
from stressing some mmotm trees during July.
Could a dirty xfs or ext4 file page somehow get marked PageSwapBacked,
so fail shrink_page_list()'s page_is_file_cache() test, and so proceed
to mapping->a_ops->writepage()?
Yes, 3.16-rc1's commit 68711a746345 ("mm, migration: add destination
page freeing callback") has provided such a way to compaction: if
migrating a SwapBacked page fails, its newpage may be put back on the
list for later use with PageSwapBacked still set, and nothing will clear
it.
Whether that can do anything worse than issue WARN_ON_ONCEs, and get
some statistics wrong, is unclear: easier to fix than to think through
the consequences.
Fixing it here, before the put_new_page(), addresses the bug directly,
but is probably the worst place to fix it. Page migration is doing too
many parts of the job on too many levels: fixing it in
move_to_new_page() to complement its SetPageSwapBacked would be
preferable, except why is it (and newpage->mapping and newpage->index)
done there, rather than down in migrate_page_move_mapping(), once we are
sure of success? Not a cleanup to get into right now, especially not
with memcg cleanups coming in 3.17.
Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We use the accessed bit to age a page at page reclaim time,
and currently we also flush the TLB when doing so.
But in some workloads TLB flush overhead is very heavy. In my
simple multithreaded app with a lot of swap to several pcie
SSDs, removing the tlb flush gives about 20% ~ 30% swapout
speedup.
Fortunately just removing the TLB flush is a valid optimization:
on x86 CPUs, clearing the accessed bit without a TLB flush
doesn't cause data corruption.
It could cause incorrect page aging and the (mistaken) reclaim of
hot pages, but the chance of that should be relatively low.
So as a performance optimization don't flush the TLB when
clearing the accessed bit, it will eventually be flushed by
a context switch or a VM operation anyway. [ In the rare
event of it not getting flushed for a long time the delay
shouldn't really matter because there's no real memory
pressure for swapout to react to. ]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Shaohua Li <shli@fusionio.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: linux-mm@kvack.org Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20140408075809.GA1764@kernel.org
[ Rewrote the changelog and the code comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Compaction uses compact_checklock_irqsave() function to periodically check
for lock contention and need_resched() to either abort async compaction,
or to free the lock, schedule and retake the lock. When aborting,
cc->contended is set to signal the contended state to the caller. Two
problems have been identified in this mechanism.
First, compaction also calls directly cond_resched() in both scanners when
no lock is yet taken. This call either does not abort async compaction,
or set cc->contended appropriately. This patch introduces a new
compact_should_abort() function to achieve both. In isolate_freepages(),
the check frequency is reduced to once by SWAP_CLUSTER_MAX pageblocks to
match what the migration scanner does in the preliminary page checks. In
case a pageblock is found suitable for calling isolate_freepages_block(),
the checks within there are done on higher frequency.
Second, isolate_freepages() does not check if isolate_freepages_block()
aborted due to contention, and advances to the next pageblock. This
violates the principle of aborting on contention, and might result in
pageblocks not being scanned completely, since the scanning cursor is
advanced. This problem has been noticed in the code by Joonsoo Kim when
reviewing related patches. This patch makes isolate_freepages_block()
check the cc->contended flag and abort.
In case isolate_freepages() has already isolated some pages before
aborting due to contention, page migration will proceed, which is OK since
we do not want to waste the work that has been done, and page migration
has own checks for contention. However, we do not want another isolation
attempt by either of the scanners, so cc->contended flag check is added
also to compaction_alloc() and compact_finished() to make sure compaction
is aborted right after the migration.
The outcome of the patch should be reduced lock contention by async
compaction and lower latencies for higher-order allocations where direct
compaction is involved.
[akpm@linux-foundation.org: fix typo in comment] Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@nvidia.com> Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Cc: David Rientjes <rientjes@google.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The compaction free scanner in isolate_freepages() currently remembers PFN
of the highest pageblock where it successfully isolates, to be used as the
starting pageblock for the next invocation. The rationale behind this is
that page migration might return free pages to the allocator when
migration fails and we don't want to skip them if the compaction
continues.
Since migration now returns free pages back to compaction code where they
can be reused, this is no longer a concern. This patch changes
isolate_freepages() so that the PFN for restarting is updated with each
pageblock where isolation is attempted. Using stress-highalloc from
mmtests, this resulted in 10% reduction of the pages scanned by the free
scanner.
Note that the somewhat similar functionality that records highest
successful pageblock in zone->compact_cached_free_pfn, remains unchanged.
This cache is used when the whole compaction is restarted, not for
multiple invocations of the free scanner during single compaction.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During compaction, update_nr_listpages() has been used to count remaining
non-migrated and free pages after a call to migrage_pages(). The
freepages counting has become unneccessary, and it turns out that
migratepages counting is also unnecessary in most cases.
The only situation when it's needed to count cc->migratepages is when
migrate_pages() returns with a negative error code. Otherwise, the
non-negative return value is the number of pages that were not migrated,
which is exactly the count of remaining pages in the cc->migratepages
list.
Furthermore, any non-zero count is only interesting for the tracepoint of
mm_compaction_migratepages events, because after that all remaining
unmigrated pages are put back and their count is set to 0.
This patch therefore removes update_nr_listpages() completely, and changes
the tracepoint definition so that the manual counting is done only when
the tracepoint is enabled, and only when migrate_pages() returns a
negative error code.
Furthermore, migrate_pages() and the tracepoints won't be called when
there's nothing to migrate. This potentially avoids some wasted cycles
and reduces the volume of uninteresting mm_compaction_migratepages events
where "nr_migrated=0 nr_failed=0". In the stress-highalloc mmtest, this
was about 75% of the events. The mm_compaction_isolate_migratepages event
is better for determining that nothing was isolated for migration, and
this one was just duplicating the info.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Async compaction terminates prematurely when need_resched(), see
compact_checklock_irqsave(). This can never trigger, however, if the
cond_resched() in isolate_migratepages_range() always takes care of the
scheduling.
If the cond_resched() actually triggers, then terminate this pageblock
scan for async compaction as well.
We're going to want to manipulate the migration mode for compaction in the
page allocator, and currently compact_control's sync field is only a bool.
Currently, we only do MIGRATE_ASYNC or MIGRATE_SYNC_LIGHT compaction
depending on the value of this bool. Convert the bool to enum
migrate_mode and pass the migration mode in directly. Later, we'll want
to avoid MIGRATE_SYNC_LIGHT for thp allocations in the pagefault patch to
avoid unnecessary latency.
This also alters compaction triggered from sysfs, either for the entire
system or for a node, to force MIGRATE_SYNC.
[akpm@linux-foundation.org: fix build]
[iamjoonsoo.kim@lge.com: use MIGRATE_SYNC in alloc_contig_range()] Signed-off-by: David Rientjes <rientjes@google.com> Suggested-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Each zone has a cached migration scanner pfn for memory compaction so that
subsequent calls to memory compaction can start where the previous call
left off.
Currently, the compaction migration scanner only updates the per-zone
cached pfn when pageblocks were not skipped for async compaction. This
creates a dependency on calling sync compaction to avoid having subsequent
calls to async compaction from scanning an enormous amount of non-MOVABLE
pageblocks each time it is called. On large machines, this could be
potentially very expensive.
This patch adds a per-zone cached migration scanner pfn only for async
compaction. It is updated everytime a pageblock has been scanned in its
entirety and when no pages from it were successfully isolated. The cached
migration scanner pfn for sync compaction is updated only when called for
sync compaction.
Greg reported that he found isolated free pages were returned back to the
VM rather than the compaction freelist. This will cause holes behind the
free scanner and cause it to reallocate additional memory if necessary
later.
He detected the problem at runtime seeing that ext4 metadata pages (esp
the ones read by "sbi->s_group_desc[i] = sb_bread(sb, block)") were
constantly visited by compaction calls of migrate_pages(). These pages
had a non-zero b_count which caused fallback_migrate_page() ->
try_to_release_page() -> try_to_free_buffers() to fail.
Memory compaction works by having a "freeing scanner" scan from one end of
a zone which isolates pages as migration targets while another "migrating
scanner" scans from the other end of the same zone which isolates pages
for migration.
When page migration fails for an isolated page, the target page is
returned to the system rather than the freelist built by the freeing
scanner. This may require the freeing scanner to continue scanning memory
after suitable migration targets have already been returned to the system
needlessly.
This patch returns destination pages to the freeing scanner freelist when
page migration fails. This prevents unnecessary work done by the freeing
scanner but also encourages memory to be as compacted as possible at the
end of the zone.
Memory migration uses a callback defined by the caller to determine how to
allocate destination pages. When migration fails for a source page,
however, it frees the destination page back to the system.
This patch adds a memory migration callback defined by the caller to
determine how to free destination pages. If a caller, such as memory
compaction, builds its own freelist for migration targets, this can reuse
already freed memory instead of scanning additional memory.
If the caller provides a function to handle freeing of destination pages,
it is called when page migration fails. If the caller passes NULL then
freeing back to the system will be handled as usual. This patch
introduces no functional change.
isolate_freepages() is currently somewhat hard to follow thanks to many
looks like it is related to the 'low_pfn' variable, but in fact it is not.
This patch renames the 'high_pfn' variable to a hopefully less confusing name,
and slightly changes its handling without a functional change. A comment made
obsolete by recent changes is also updated.
[akpm@linux-foundation.org: comment fixes, per Minchan]
[iamjoonsoo.kim@lge.com: cleanups] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Cc: Dongjun Shin <d.j.shin@samsung.com> Cc: Sunghwan Yun <sunghwan.yun@samsung.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes read_cache_page_async() which wasn't really needed
anywhere and simplifies the code around it a bit.
read_cache_page_async() is useful when we want to read a page into the
cache without waiting for it to complete. This happens when the
appropriate callback 'filler' doesn't complete its read operation and
releases the page lock immediately, and instead queues a different
completion routine to do that. This never actually happened anywhere in
the code.
read_cache_page_async() had 3 different callers:
- read_cache_page() which is the sync version, it would just wait for
the requested read to complete using wait_on_page_read().
- JFFS2 would call it from jffs2_gc_fetch_page(), but the filler
function it supplied doesn't do any async reads, and would complete
before the filler function returns - making it actually a sync read.
- CRAMFS would call it using the read_mapping_page_async() wrapper, with
a similar story to JFFS2 - the filler function doesn't do anything that
reminds async reads and would always complete before the filler function
returns.
To sum it up, the code in mm/filemap.c never took advantage of having
read_cache_page_async(). While there are filler callbacks that do async
reads (such as the block one), we always called it with the
read_cache_page().
This patch adds a mandatory wait for read to complete when adding a new
page to the cache, and removes read_cache_page_async() and its wrappers.
MADV_WILLNEED currently does not read swapped out shmem pages back in.
Commit 0cd6144aadd2 ("mm + fs: prepare for non-page entries in page
cache radix trees") made find_get_page() filter exceptional radix tree
entries but failed to convert all find_get_page() callers that WANT
exceptional entries over to find_get_entry(). One of them is shmem swap
readahead in madvise, which now skips over any swap-out records.
Convert it to find_get_entry().
Fixes: 0cd6144aadd2 ("mm + fs: prepare for non-page entries in page cache radix trees") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
shmem mappings already contain exceptional entries where swap slot
information is remembered.
To be able to store eviction information for regular page cache, prepare
every site dealing with the radix trees directly to handle entries other
than pages.
The common lookup functions will filter out non-page entries and return
NULL for page cache holes, just as before. But provide a raw version of
the API which returns non-page entries as well, and switch shmem over to
use it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The radix tree hole searching code is only used for page cache, for
example the readahead code trying to get a a picture of the area
surrounding a fault.
It sufficed to rely on the radix tree definition of holes, which is
"empty tree slot". But this is about to change, though, as shadow page
descriptors will be stored in the page cache after the actual pages get
evicted from memory.
Move the functions over to mm/filemap.c and make them native page cache
operations, where they can later be adapted to handle the new definition
of "page cache hole".
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Page cache radix tree slots are usually stabilized by the page lock, but
shmem's swap cookies have no such thing. Because the overall truncation
loop is lockless, the swap entry is currently confirmed by a tree lookup
and then deleted by another tree lookup under the same tree lock region.
Use radix_tree_delete_item() instead, which does the verification and
deletion with only one lookup. This also allows removing the
delete-only special case from shmem_radix_tree_replace().
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Provide a function that does not just delete an entry at a given index,
but also allows passing in an expected item. Delete only if that item
is still located at the specified index.
This is handy when lockless tree traversals want to delete entries as
well because they don't have to do an second, locked lookup to verify
the slot has not changed under them before deleting the entry.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Metin Doslu <metin@citusdata.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ozgun Erdogan <ozgun@citusdata.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / linux-stable / log