This patch fixes several problems:
- The legacy backlight value might be set at interrupt time. Introduced
a worker to prevent it from directly calling the backlight code.
- via-pmu allows the backlight to be grabbed, in which case we need to
prevent other kernel code from changing the brightness.
- Don't send PMU requests in via-pmu-backlight when the machine is about
to sleep or waking up.
- More Kconfig fixes.
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The backlight and lcd subsystems can be notified by the framebuffer layer
of blanking events. However, these subsystems, as a whole, can function
independently from the framebuffer layer. But in order to enable to the
lcd and backlight subsystems, the framebuffer has to be compiled also,
effectively sucking in a huge amount of unneeded code.
To prevent dependency problems, separate out the framebuffer notification
mechanism from the framebuffer layer and permanently link it to the kernel.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is currently no affected user in the tree, but usage is less
surprising that way.
Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kprobe inserts breakpoint instruction in probepoint and then jumps to
instruction slot when breakpoint is hit, the instruction slot icache must
be consistent with dcache. Here is the patch which invalidates instruction
slot icache area.
Without this patch, in some machines there will be fault when executing
instruction slot where icache content is inconsistent with dcache.
Signed-off-by: bibo,mao <bibo.mao@intel.com>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Enable delay accounting by default so that feature gets coverage testing
without requiring special measures.
Earlier, it was off by default and had to be enabled via a boot time param.
This patch reverses the default behaviour to improve coverage testing. It
can be removed late in the kernel development cycle if its believed users
shouldn't have to incur any cost if they don't want delay accounting. Or
it can be retained forever if the utility of the stats is deemed common
enough to warrant keeping the feature on.
Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Complete the separation of delay accounting and taskstats by ignoring the
return value of delay accounting functions that fill in parts of taskstats
before it is sent out (either in response to a command or as part of a task
exit).
Also make delayacct_add_tsk return silently when delay accounting is turned
off rather than treat it as an error.
Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
IRQs need refcounting and a state flag to track whether the the IRQ should
be enabled or disabled as a "normal IRQ" source after a series of calls to
{en,dis}able_irq(). For shared IRQs, the IRQ must be enabled so long as at
least one driver needs it active.
Likewise, IRQs need the same support to track whether the IRQ should be
enabled or disabled as a "wakeup event" source after a series of calls to
{en,dis}able_irq_wake(). For shared IRQs, the IRQ must be enabled as a
wakeup source during sleep so long as at least one driver needs it. But
right now they _don't have_ that refcounting ... which means sharing a
wakeup-capable IRQ can't work correctly in some configurations.
This patch adds the refcount and flag mechanisms to set_irq_wake() -- which
is what {en,dis}able_irq_wake() call -- and minimal documentation of what
the irq wake mechanism does.
Drivers relying on the older (broken) "toggle" semantics will trigger a
warning; that'll be a handful of drivers on ARM systems.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Events sent by Process Events Connector from a 64-bit kernel are not binary
compatible with a 32-bit userspace program because the "timestamp" field
(struct timespec) is not arch independent. This affects the fields that
follow "timestamp" as they will be be off by 8 bytes.
This is a problem for 32-bit userspace programs running with 64-bit kernels
on ppc64, s390, x86-64.. any "biarch" system.
Matt had submitted a different solution to lkml as an RFC earlier. We have
since switched to a solution recommended by Evgeniy Polyakov.
This patch fixes the problem by changing the timestamp to be a __u64, which
stores the number of nanoseconds.
Tested on a x86_64 system with both 32 bit application and 64 bit
application and on a i386 system.
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The inode number out of an NFS file handle gets passed eventually to
ext3_get_inode_block() without any checking. If ext3_get_inode_block()
allows it to trigger an error, then bad filehandles can have unpleasant
effect - ext3_error() will usually cause a forced read-only remount, or a
panic if `errors=panic' was used.
So remove the call to ext3_error there and put a matching check in
ext3/namei.c where inode numbers are read off storage.
[akpm@osdl.org: fix off-by-one error]
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: <stable@kernel.org>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 3734/1: Fix the unused variable warning in __iounmap()
[ARM] 3737/1: Export ARM copy/clear_user_page symbols
[ARM] 3736/1: xscale: don't mis-report 80219 as an iop32x
[ARM] 3733/2: S3C24XX: Remove old IDE registers in Anubis
[ARM] 3732/1: S3C24XX: tidy syntax in osiris and anubis machines
[ARM] Fix SMP booting
[ARM] 3731/1: Allow IRQ definitions of IQ80331 and IQ80332 to co-exist
[ARM] 3730/1: ep93xx: enable usb ohci driver in the defconfig
[ARM] Fix cats build
It was broken before. But having it is important as possible hardware
bug workaround.
And previously there was no way to force swiotlb if there is another IOMMU.
Side effect is that iommu=force won't force swiotlb anymore even if there
isn't another IOMMU.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Calgary hits a NULL pointer dereference when booting in a multi-chassis
NUMA system. See Redhat bugzilla number 198498, found by Konrad
Rzeszutek (konradr@redhat.com).
There are many issues that had to be resolved to fix this problem.
Firstly when I originally wrote the code to handle NUMA systems, I
had a large misunderstanding that was not corrected until now. That was
that I thought the "number of nodes online" referred to number of
physical systems connected. So that if NUMA was disabled, there
would only be 1 node and it would only show that node's PCI bus.
In reality if NUMA is disabled, the system displays all of the
connected chassis as one node but is only ignorant of the delays
in accessing main memory. Therefore, references to num_online_nodes()
and MAX_NUMNODES are incorrect and need to be set to the maximum
number of nodes that can be accessed (which are 8). I created a
variable, MAX_NUM_CHASSIS, and set it to 8 to fix this.
Secondly, when walking the PCI in detect_calgary, the code only
checked the first "slot" when looking to see if a device is present.
This will work for most cases, but unfortunately it isn't always the
case. In the NUMA MXE drawers, there are USB devices present on the
3rd slot (with slot 1 being empty). So, to work around this, all
slots (up to 8) are scanned to see if there are any devices present.
Lastly, the bus is being enumerated on large systems in a different
way the we originally thought. This throws the ugly logic we had
out the window. To more elegantly handle this, I reorganized the
kva array to be sparse (which removed the need to have any bus number
to kva slot logic in tce.c) and created a secondary space array to
contain the bus number to phb mapping.
With these changes Calgary boots on an x460 with 4 nodes with and
without NUMA enabled.
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix robust PI-futexes to be properly unlocked on unexpected exit.
For this to work the kernel has to know whether a futex is a PI or a
non-PI one, because the semantics are different. Since the space in
relevant glibc data structures is extremely scarce, the best solution is
to encode the 'PI' information in bit 0 of the robust list pointer.
Existing (non-PI) glibc robust futexes have this bit always zero, so the
ABI is kept. New glibc with PI-robust-futexes will set this bit.
Further fixes from Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In x86_64 platform, INT1 and INT3 trap stack is IST stack called DEBUG_STACK,
when INT1/INT3 trap happens, system will switch to DEBUG_STACK by hardware.
Current DEBUG_STACK size is 4K, when int1/int3 trap happens, kernel will
minus current DEBUG_STACK IST value by 4k. But if int3/int1 trap is nested,
it will destroy other vector's IST stack. This patch modifies this, it sets
DEBUG_STACK size as 8K and allows two level of nested int1/int3 trap.
Kprobe DEBUG_STACK may be nested, because kprobe handler may be probed
by other kprobes.
Thanks jbeulich for pointing out error in the first patch.
[AK: nested kprobes are pretty dubious. Hopefully one nest
will be enough. This will cost 8K per CPU (4K more than before)]
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some drives claim they support cache flushing, but get seriously
confused if you try. Add this option to be able to boot with
barriers enabled by default.
Signed-off-by: Jens Axboe <axboe@suse.de>
Something is wrong with the 3-multiply (vs. 4-multiply) optimized
version of _FP_MUL_MEAT_2_*(), so just use the slower version
which actually computes correct values.
Noticed by Rene Rebe
Signed-off-by: David S. Miller <davem@davemloft.net>
ieee80211_rx_any is new to 2.6.18-rc1, even though it appears this function
was never completed:
http://lists.sipsolutions.net/pipermail/softmac-dev/2006-February/000103.html
This patch changes ieee80211_rx_any to always claim the skb, which avoids
further driver complexity and the possibility of leaking management frames.
It also exports the function so that people can actually use it.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
zd1211 needs this functionality, no point duplicating it.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch implements ERP handling in softmac so that the drivers can support
protection and preambles properly.
I added a new struct, ieee80211softmac_bss_info, which is used for
BSS-dependent variables like these.
A new hook has been added (bssinfo_change), which allows the drivers to be
notified when anything in bssinfo changes.
I modified the txrates_change API to match the bssinfo_change API. The
existing one is a little messy and the usefulness of providing the old rates
is questionable (and can be implemented at driver level if really necessary).
No drivers are using this API (yet), so this should be safe.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This adds a flag to the ieee80211_network structure which indicates whether
the stored erp_value is valid (a check against 0 is not enough, since an ERP
of 0 is valid and very meaningful).
I also added the ERP IE bit-definitions to ieee80211.h.
This is needed by some upcoming softmac patches.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SCSI] esp: Fix build.
[SPARC]: Fix SA_STATIC_ALLOC value.
[SPARC64]: Explicitly print return PC when the kernel fault PC is bogus.
The patch below moves the cpu hotplugging higher up in the cpufreq
layering; this is needed to avoid recursive taking of the cpu hotplug
lock and to otherwise detangle the mess.
The new rules are:
1. you must do lock_cpu_hotplug() around the following functions:
__cpufreq_driver_target
__cpufreq_governor (for CPUFREQ_GOV_LIMITS operation only)
__cpufreq_set_policy
2. governer methods (.governer) must NOT take the lock_cpu_hotplug()
lock in any way; they are called with the lock taken already
3. if your governer spawns a thread that does things, like calling
__cpufreq_driver_target, your thread must honor rule #1.
4. the policy lock and other cpufreq internal locks nest within
the lock_cpu_hotplug() lock.
I'm not entirely happy about how the __cpufreq_governor rule ended up
(conditional locking rule depending on the argument) but basically all
callers pass this as a constant so it's not too horrible.
The patch also removes the cpufreq_governor() function since during the
locking audit it turned out to be entirely unused (so no need to fix it)
The patch works on my testbox, but it could use more testing
(otoh... it can't be much worse than the current code)
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add bridge netfilter deferred output hooks to feature-removal-schedule
and disable them by default. Until their removal they will be
activated by the physdev match when needed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev_alloc_skb is designated for RX descriptors, not TX. (Some drivers
use it for the latter anyway, but that's a different story)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
skbuff.h has an #ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB to allow
architectures to reimplement __dev_alloc_skb. It's not set on any
architecture and now that we have an architecture-overrideable
NET_SKB_PAD there is not point at all to have one either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Patch from Martin Michlmayr
ARCH_IQ80331 and MACH_IQ80332 can be enabled at the same time but a
header file makes certain IRQ definitions conditional, leading to
the following compilation error when both platforms are enabled:
arch/arm/mach-iop3xx/iq80332-pci.c: In function 'iq80332_map_irq':
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: 'IRQ_IQ80332_INTA' undeclared (first use in this function)
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: (Each undeclared identifier is reported only once
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: for each function it appears in.)
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: 'IRQ_IQ80332_INTB' undeclared (first use in this function)
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: 'IRQ_IQ80332_INTC' undeclared (first use in this function)
arch/arm/mach-iop3xx/iq80332-pci.c:54: error: 'IRQ_IQ80332_INTD' undeclared (first use in this function)
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In PSCHED_TADD and PSCHED_TADD2, if delta is less than tv.tv_usec (so,
less than USEC_PER_SEC too) then tv_res will be smaller than tv. The
affectation "(tv_res).tv_usec = __delta;" is wrong. The fix is to
revert to the original code before
4ee303dfea and change the 'if' in
'while'.
[Shuya MAEDA: "while (__delta >= USEC_PER_SEC){ ... }" instead of
"while (__delta > USEC_PER_SEC){ ... }"]
Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Validate MADs sent by userspace clients for spec compliance with
C13-18.1.1 (prevent duplicate requests and responses sent on the
same port). Without this, RMPP transactions get aborted because
of duplicate packets.
This patch is similar to that provided by Jack Morgenstein.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The CPU hotplug locking was quite messy, with a recursive lock to
handle the fact that both the actual up/down sequence wanted to
protect itself from being re-entered, but the callbacks that it
called also tended to want to protect themselves from CPU events.
This splits the lock into two (one to serialize the whole hotplug
sequence, the other to protect against the CPU present bitmaps
changing). The latter still allows recursive usage because some
subsystems (ondemand policy for cpufreq at least) had already gotten
too used to the lax locking, but the locking mistakes are hopefully
now less fundamental, and we now warn about recursive lock usage
when we see it, in the hope that it can be fixed.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
[TIPC]: Removing useless casts
[IPV4]: Fix nexthop realm dumping for multipath routes
[DUMMY]: Avoid an oops when dummy_init_one() failed
[IFB] After ifb_init_one() failed, i is increased. Decrease
[NET]: Fix reversed error test in netif_tx_trylock
[MAINTAINERS]: Mark LAPB as Oprhan.
[NET]: Conversions from kmalloc+memset to k(z|c)alloc.
[NET]: sun happymeal, little pci cleanup
[IrDA]: Use alloc_skb() in IrDA TX path
[I/OAT]: Remove pci_module_init() from Intel I/OAT DMA engine
[I/OAT]: net/core/user_dma.c should #include <net/netdma.h>
[SCTP]: ADDIP: Don't use an address as source until it is ASCONF-ACKed
[SCTP]: Set chunk->data_accepted only if we are going to accept it.
[SCTP]: Verify all the paths to a peer via heartbeat before using them.
[SCTP]: Unhash the endpoint in sctp_endpoint_free().
[SCTP]: Check for NULL arg to sctp_bucket_destroy().
[PKT_SCHED] netem: Fix slab corruption with netem (2nd try)
[WAN]: Converted synclink drivers to use netif_carrier_*()
[WAN]: Cosmetic changes to N2 and C101 drivers
[WAN]: Added missing netif_dormant_off() to generic HDLC
...
A non-zero return value indicates success from spin_trylock,
not error.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Every file should #include the headers containing the prototypes for
its global functions.
Especially in cases like this one where gcc can tell us through a
compile error that the prototype was wrong...
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This implements Rules D1 and D4 of Sec 4.3 in the ADDIP draft.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements Path Initialization procedure as described in
Sec 2.36 of RFC4460.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sabre and Psycho PCI controllers can have partial interrupt-map
properties, meaning that on-board devices don't match up to any
entries. Instead, they are fully specified from the beginning and
we should pass them directly to the IRQ translator as-is.
Also, fill in the necessary translator slots for the "graphics"
and "expansion UPA" interrupts on Sabre, Psycho, and SYSIO SBUS.
Increase PROMREG_MAX to 24, as seen on SUNW,ffb devices.
Finally, prevent accidentally writing past the end of the of_device
struct resource[] and irqs[] arrays. Spit out a log message when
we ignore some entries because there are too many of them.
Signed-off-by: David S. Miller <davem@davemloft.net>
* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6: (38 commits)
[SCSI] More buffer->request_buffer changes
[SCSI] mptfusion: bump version to 3.04.01
[SCSI] mptfusion: misc fix's
[SCSI] mptfusion: firmware download boot fix's
[SCSI] mptfusion: task abort fix's
[SCSI] mptfusion: sas nexus loss support
[SCSI] mptfusion: sas loginfo update
[SCSI] mptfusion: mptctl panic when loading
[SCSI] mptfusion: sas enclosures with smart drive
[SCSI] NCR_D700: misc fixes (section and argument ordering)
[SCSI] scsi_debug: must_check fixes
[SCSI] scsi_transport_sas: kill the use of channel
[SCSI] scsi_transport_sas: add expander backlink
[SCSI] hide EH backup data outside the scsi_cmnd
[SCSI] ibmvscsi: handle inactive SCSI target during probe
[SCSI] ibmvscsi: allocate lpevents for ibmvscsi on iseries
[SCSI] aic7[9x]xx: Remove last vestiges of reverse_scan
[SCSI] aha152x: stop poking at saved scsi_cmnd members
[SCSI] st.c: Improve sense output
[SCSI] lpfc 8.1.7: Change version number to 8.1.7
...
Update ata_eh_about_to_do() and ata_eh_done() to improve EH action and
EHI flag handling.
* There are two types of EHI flags - one which expires on successful
EH and the other which expires on a successful reset. Make this
distinction clear.
* Unlike other EH actions, reset actions are represented by two EH
action masks and a EHI modifier. Implement correct about_to_do/done
semantics for resets. That is, prior to reset, related EH info is
sucked in from ehi and cleared, and after reset is complete, related
EH info in ehc is cleared.
These changes improve consistency and remove unnecessary EH actions
caused by stale EH action masks and EHI flags.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Add missing volatile to the get_clock / get_cycles inline assemblies
to avoid that consecutive calls get optimized away.
Signed-off-by: Andreas Krebbel <krebbel1@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[VLAN]: __vlan_hwaccel_rx can use the faster ether_compare_addr
[PKT_SCHED] HTB: initialize upper bound properly
[IPV4]: Clear skb cb on IP input
[NET]: Update frag_list in pskb_trim
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit. Since it is not currently used in the
kernel this patch removes it so that new code does not include it.
All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead. But this is
still moot since it is not used anyway.
Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>