Remove Voyager Kconfig quirk: just like any other hardware platform
users of Voyager systems can configure in the hardware drivers they need.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86/Voyager does not build right now and it's unclear whether it will
be cleaned up and ported to the subarch-less 32-bit x86 code - so disable
it for now.
If it's fixed we'll re-enable it - or remove it after some time. There's
a very low number of systems running development kernels on x86/Voyager
currently. (one or two on the whole planet)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CONFIG_BROKEN has been removed from the upstream kernel years ago,
but X86_VOYAGER still had a stale reference to it - remove it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: standardize all x86 platforms on same setup code
With the preceding changes, Voyager can use the same per-cpu setup
code as all the other x86 platforms.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Make X86 SGI Ultraviolet support configurable. Saves about 13K of text size
on my modest config.
text data bss dec hex filename
6770537 1158680 694356 8623573 8395d5 vmlinux
6757492 1157664 694228 8609384 835e68 vmlinux.nouv
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CONFIG_FRAME_POINTERS=y results in much better debug info for the
kernel (clear and precise backtraces), with the only drawback being
a ~1% increase in kernel size.
So offer it unconditionally and enable it by default.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Bug fix (we should not show this menu on irrelevant architectures)
Make the config machinery to drive the gzip/bzip2/lzma selection
dependent on the architecture advertising HAVE_KERNEL_* so that we
don't display this for architectures where it doesn't matter.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
These two IOMMUs can implement the current version of this API. So
select the API if one or both of these IOMMU drivers is selected.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
x86: export vector_used_by_percpu_irq
x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
sched: nominate preferred wakeup cpu, fix
x86: fix lguest used_vectors breakage, -v2
x86: fix warning in arch/x86/kernel/io_apic.c
sched: fix warning in kernel/sched.c
sched: move test_sd_parent() to an SMP section of sched.h
sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
sched: activate active load balancing in new idle cpus
sched: bias task wakeups to preferred semi-idle packages
sched: nominate preferred wakeup cpu
sched: favour lower logical cpu number for sched_mc balance
sched: framework for sched_mc/smt_power_savings=N
sched: convert BALANCE_FOR_xx_POWER to inline functions
x86: use possible_cpus=NUM to extend the possible cpus allowed
x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
x86: update io_apic.c to the new cpumask code
x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
x86: xen: use smp_call_function_many()
x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
...
Fixed up trivial conflict in kernel/time/tick-sched.c manually
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, sparseirq: clean up Kconfig entry
x86: turn CONFIG_SPARSE_IRQ off by default
sparseirq: fix numa_migrate_irq_desc dependency and comments
sparseirq: add kernel-doc notation for new member in irq_desc, -v2
locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP
sparseirq, xen: make sure irq_desc is allocated for interrupts
sparseirq: fix !SMP building, #2
x86, sparseirq: move irq_desc according to smp_affinity, v7
proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ
sparse irqs: add irqnr.h to the user headers list
sparse irqs: handle !GENIRQ platforms
sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build
sparseirq: fix Alpha build failure
sparseirq: fix typo in !CONFIG_IO_APIC case
x86, MSI: pass irq_cfg and irq_desc
x86: MSI start irq numbering from nr_irqs_gsi
x86: use NR_IRQS_LEGACY
sparse irq_desc[] array: core kernel and x86 changes
genirq: record IRQ_LEVEL in irq_desc[]
irq.h: remove padding from irq_desc on 64bits
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
hrtimers: fix warning in kernel/hrtimer.c
x86: make sure we really have an hpet mapping before using it
x86: enable HPET on Fujitsu u9200
linux/timex.h: cleanup for userspace
posix-timers: simplify de_thread()->exit_itimers() path
posix-timers: check ->it_signal instead of ->it_pid to validate the timer
posix-timers: use "struct pid*" instead of "struct task_struct*"
nohz: suppress needless timer reprogramming
clocksource, acpi_pm.c: put acpi_pm_read_slow() under CONFIG_PCI
nohz: no softirq pending warnings for offline cpus
hrtimer: removing all ur callback modes, fix
hrtimer: removing all ur callback modes, fix hotplug
hrtimer: removing all ur callback modes
x86: correct link to HPET timer specification
rtc-cmos: export second NVRAM bank
Fixed up conflicts in sound/drivers/pcsp/pcsp.c and sound/core/hrtimer.c
manually.
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
sched, trace: update trace_sched_wakeup()
tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
Revert "x86: disable X86_PTRACE_BTS"
ring-buffer: prevent false positive warning
ring-buffer: fix dangling commit race
ftrace: enable format arguments checking
x86, bts: memory accounting
x86, bts: add fork and exit handling
ftrace: introduce tracing_reset_online_cpus() helper
tracing: fix warnings in kernel/trace/trace_sched_switch.c
tracing: fix warning in kernel/trace/trace.c
tracing/ring-buffer: remove unused ring_buffer size
trace: fix task state printout
ftrace: add not to regex on filtering functions
trace: better use of stack_trace_enabled for boot up code
trace: add a way to enable or disable the stack tracer
x86: entry_64 - introduce FTRACE_ frame macro v2
tracing/ftrace: add the printk-msg-only option
tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
x86, bts: correctly report invalid bts records
...
Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
Impact: reduce kconfig variable scope and clean up
Bartlomiej pointed out that the config dependencies and comments are not right.
update it depend to NUMA, and fix some comments
Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: activates new off-stack cpumask code on MAXSMP (non-default) x86 configs
Set MAXSMP to enable CONFIG_CPUMASK_OFFSTACK which moves cpumask's off
the stack (and in structs) when using cpumask_var_t.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hy>
Impact: build fix
make intr_remapping.c to include smp.h, so could use boot_cpu_id there
also remove old change that disabling sparseirq with !SMP
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: improve NUMA handling by migrating irq_desc on smp_affinity changes
if CONFIG_NUMA_MIGRATE_IRQ_DESC is set:
- make irq_desc to go with affinity aka irq_desc moving etc
- call move_irq_desc in irq_complete_move()
- legacy irq_desc is not moved, because they are allocated via static array
for logical apic mode, need to add move_desc_in_progress_in_same_domain,
otherwise it will not be moved ==> also could need two phases to get
irq_desc moved.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: reduce bug table size
This allows reducing the bug table size by half. Perhaps there are
other 64-bit architectures that could also make use of this.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We merge the irq/sparseirq, x86/quirks and x86/reboot trees into the
cpus4096 tree because the io-apic changes in the sparseirq change
conflict with the cpumask changes in the cpumask tree, and we
want to resolve those.
Ingo Molnar wrote:
>>> drivers/pci/intr_remapping.c: In function 'irq_2_iommu_alloc':
>>> drivers/pci/intr_remapping.c:72: error: 'boot_cpu_id' undeclared (first use in this function)
>>> drivers/pci/intr_remapping.c:72: error: (Each undeclared identifier is reported only once
>>> drivers/pci/intr_remapping.c:72: error: for each function it appears in.)
sparseirq should only be used with SMP for now.
Impact: new feature
Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.
To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.
When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).
This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove CONFIG_APM_REAL_MODE_POWER_OFF like CONFIG_APM_POWER_OFF which
has been done for linux-2.2.14pre8 (http://lkml.org/lkml/1999/11/23/3).
Re-introducing CONFIG_APM_POWER_OFF got nack-ed. Stephen didn't bother
to remove CONFIG_APM_REAL_MODE_POWER_OFF, let's get rid of it now.
Reference: http://lkml.org/lkml/2008/5/7/97
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: extend and enable the function graph tracer to 64-bit x86
This patch implements the support for function graph tracer under x86-64.
Both static and dynamic tracing are supported.
This causes some small CPP conditional asm on arch/x86/kernel/ftrace.c I
wanted to use probe_kernel_read/write to make the return address
saving/patching code more generic but it causes tracing recursion.
That would be perhaps useful to implement a notrace version of these
function for other archs ports.
Note that arch/x86/process_64.c is not traced, as in X86-32. I first
thought __switch_to() was responsible of crashes during tracing because I
believed current task were changed inside but that's actually not the
case (actually yes, but not the "current" pointer).
So I will have to investigate to find the functions that harm here, to
enable tracing of the other functions inside (but there is no issue at
this time, while process_64.c stays out of -pg flags).
A little possible race condition is fixed inside this patch too. When the
tracer allocate a return stack dynamically, the current depth is not
initialized before but after. An interrupt could occur at this time and,
after seeing that the return stack is allocated, the tracer could try to
trace it with a random uninitialized depth. It's a prevention, even if I
hadn't problems with it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add new API for drivers
Add implementation of readq/writeq to x86_32, and add config value to
the x86 architecture to determine existence of readq/writeq.
Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
This patch changes the name of the "return function tracer" into
function-graph-tracer which is a more suitable name for a tracing
which makes one able to retrieve the ordered call stack during
the code flow.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: update documentation / help text
Original link is dead.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
User stack tracing is just implemented for x86, but it is not x86 specific.
Introduce a generic config flag, that is currently enabled only for x86.
When other arches implement it, they will have to
SELECT USER_STACKTRACE_SUPPORT.
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86/numa' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: make NUMA on 32-bit depend on EXPERIMENTAL again
x86, hibernate: fix breakage on x86_32 with CONFIG_NUMA set
Impact: clean up
We can autodetect those system that need cluster apic, and update genapic
accordingly.
We can also remove wakeup.h for e7000, because it's default one is now
the same as overall default mach_wakecpu.h
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fixes korg bugzilla 11980
A kernel for a 64bit x86 system should always contain the swiotlb code
in case it is booted on a machine without any hardware IOMMU supported
by the kernel and more than 4GB of RAM. This patch changes Kconfig to
always compile swiotlb into the kernel for x86_64.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
My previous patch to make CONFIG_NUMA on x86_32 depend on BROKEN
turned out to be unnecessary, after all, since the source of the
hibernation vs CONFIG_NUMA problem turned out to be the fact that
we didn't take the NUMA KVA remapping into account in the
hibernation code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: documentation update
Chris Snook pointed out that it's Core i7, not Core 7i.
Reported-by: Chris Snook <csnook@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build/boot fix for x86/Voyager
This change:
| commit 3d44223327
| Author: Jens Axboe <jens.axboe@oracle.com>
| Date: Thu Jun 26 11:21:34 2008 +0200
|
| Add generic helpers for arch IPI function calls
didn't wire up the voyager smp call function correctly, so do that
here. Also make CONFIG_USE_GENERIC_SMP_HELPERS a def_bool y again,
since we now use the generic helpers for every x86 architecture.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <Jens.Axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add infrastructure for function-return tracing
Add low level support for ftrace return tracing.
This plug-in stores return addresses on the thread_info structure of
the current task.
The index of the current return address is initialized when the task
is the first one (init) and when a process forks (the child). It is
not needed when a task does a sys_execve because after this syscall,
it still needs to return on the kernel functions it called.
Note that the code of return_to_handler has been suggested by Steven
Rostedt as almost all of the ideas of improvements in this V3.
For purpose of security, arch/x86/kernel/process_32.c is not traced
because __switch_to() changes the current task during its execution.
That could cause inconsistency in the stored return address of this
function even if I didn't have any crash after testing with tracing on
this function enabled.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, change .config option name
We had this ugly config name for a long time for hysteric raisons.
Rename it to a saner name.
We still cannot get rid of it completely, until /proc/<pid>/stack
usage replaces WCHAN usage for good.
We'll be able to do that in the v2.6.29/v2.6.30 timeframe.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While investigating the failure of hibernation on 32-bit x86 with
CONFIG_NUMA set, as described in this message
http://marc.info/?l=linux-kernel&m=122634118116226&w=4
I asked some people for help and I was told that it wasn't really
worth the effort, because CONFIG_NUMA was generally broken on 32-bit
x86 systems and it shouldn't be used in such configs. For this
reason, make CONFIG_NUMA depend on BROKEN instead of EXPERIMENTAL on
x86-32.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Pavel Machek <pavel@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
Revert "x86: default to reboot via ACPI"
x86: align DirectMap in /proc/meminfo
AMD IOMMU: fix lazy IO/TLB flushing in unmap path
x86: add smp_mb() before sending INVALIDATE_TLB_VECTOR
x86: remove VISWS and PARAVIRT around NR_IRQS puzzle
x86: mention ACPI in top-level Kconfig menu
x86: size NR_IRQS on 32-bit systems the same way as 64-bit
x86: don't allow nr_irqs > NR_IRQS
x86/docs: remove noirqbalance param docs
x86: don't use tsc_khz to calculate lpj if notsc is passed
x86, voyager: fix smp_intr_init() compile breakage
AMD IOMMU: fix detection of NP capable IOMMUs
Enable the wchan config menu item for now on x86-64 arch? This will
at least allow people to enable/disable frame pointers on scheduler
functions.
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: clarify/update CONFIG_NUMA text
CONFIG_NUMA description talk about a bit old thing.
So, following changes are better.
o CONFIG_NUMA is no longer EXPERIMENTAL
o Opteron is not the only processor of NUMA topology on x86_64 no longer,
but also Intel Core7i has it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: clarify menuconfig text
Mention ACPI in the top-level menu to give a clue as to where
it lives. This matches what ia64 does.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: quick start and stop of function tracer
This patch adds a way to disable the function tracer quickly without
the need to run kstop_machine. It adds a new variable called
function_trace_stop which will stop the calls to functions from mcount
when set. This is just an on/off switch and does not handle recursion
like preempt_disable().
It's main purpose is to help other tracers/debuggers start and stop tracing
fuctions without the need to call kstop_machine.
The config option HAVE_FUNCTION_TRACE_MCOUNT_TEST is added for archs
that implement the testing of the function_trace_stop in the mcount
arch dependent code. Otherwise, the test is done in the C code.
x86 is the only arch at the moment that supports this.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
clean up ifdefs: change #ifdef CONFIG_X86_32/64 to
CONFIG_HAVE_ATOMIC_IOMAP.
flip around the #ifdef sections to clean up the structure.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: enable CONFIG_MEMORY_HOTREMOVE feature on x86. (default-off)
Memory hotremove functionality can currently be configured into
the ia64, powerpc, and s390 kernels.
This patch makes it possible to configure the memory hotremove
functionality into the x86 kernel as well.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix on x86/Voyager
Given commits like this:
| Author: Suresh Siddha <suresh.b.siddha@intel.com>
| Date: Tue Jul 29 10:29:19 2008 -0700
|
| x86, xsave: enable xsave/xrstor on cpus with xsave support
Which deliberately expose boot cpu dependence to pieces of the system,
I think it's time to explicitly have a variable for it to prevent this
continual misassumption that the boot CPU is zero.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
DIRECT_GBPAGES was under DEBUG_KERNEL && EXPERIMENTAL and disabled by default.
Turn it on by default and put it under EMBEDDED.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The Intel 7300 Memory Controller supports dynamic throttling of memory which can
be used to save power when system is idle. This driver does the memory
throttling when all CPUs are idle on such a system.
Refer to "Intel 7300 Memory Controller Hub (MCH)" datasheet
for the config space description.
Signed-off-by: Andy Henroid <andrew.d.henroid@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
This merges branches irq/genirq, irq/sparseirq-v4, timers/hpet-percpu
and x86/uv.
The sparseirq branch is just preliminary groundwork: no sparse IRQs are
actually implemented by this tree anymore - just the new APIs are added
while keeping the old way intact as well (the new APIs map 1:1 to
irq_desc[]). The 'real' sparse IRQ support will then be a relatively
small patch ontop of this - with a v2.6.29 merge target.
* 'genirq-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (178 commits)
genirq: improve include files
intr_remapping: fix typo
io_apic: make irq_mis_count available on 64-bit too
genirq: fix name space collisions of nr_irqs in arch/*
genirq: fix name space collision of nr_irqs in autoprobe.c
genirq: use iterators for irq_desc loops
proc: fixup irq iterator
genirq: add reverse iterator for irq_desc
x86: move ack_bad_irq() to irq.c
x86: unify show_interrupts() and proc helpers
x86: cleanup show_interrupts
genirq: cleanup the sparseirq modifications
genirq: remove artifacts from sparseirq removal
genirq: revert dynarray
genirq: remove irq_to_desc_alloc
genirq: remove sparse irq code
genirq: use inline function for irq_to_desc
genirq: consolidate nr_irqs and for_each_irq_desc()
x86: remove sparse irq from Kconfig
genirq: define nr_irqs for architectures with GENERIC_HARDIRQS=n
...
Due to confusion between the ftrace infrastructure and the gcc profiling
tracer "ftrace", this patch renames the config options from FTRACE to
FUNCTION_TRACER. The other two names that are offspring from FTRACE
DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.
This patch was generated mostly by script, and partially by hand.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch implements a new freezer subsystem in the control groups
framework. It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.
The freezer subsystem in the container filesystem defines a file named
freezer.state. Writing "FROZEN" to the state file will freeze all tasks
in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup. Reading will return the current state.
* Examples of usage :
# mkdir /containers/freezer
# mount -t cgroup -ofreezer freezer /containers
# mkdir /containers/0
# echo $some_pid > /containers/0/tasks
to get status of the freezer subsystem :
# cat /containers/0/freezer.state
RUNNING
to freeze all tasks in the container :
# echo FROZEN > /containers/0/freezer.state
# cat /containers/0/freezer.state
FREEZING
# cat /containers/0/freezer.state
FROZEN
to unfreeze all tasks in the container :
# echo RUNNING > /containers/0/freezer.state
# cat /containers/0/freezer.state
RUNNING
This is the basic mechanism which should do the right thing for user space
task in a simple scenario.
It's important to note that freezing can be incomplete. In that case we
return EBUSY. This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time. After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read. The state will remain
"FREEZING" until one of these things happens:
1) Userspace cancels the freezing operation by writing "RUNNING" to
the freezer.state file
2) Userspace retries the freezing operation by writing "FROZEN" to
the freezer.state file (writing "FREEZING" is not legal
and returns EIO)
3) The tasks that blocked the cgroup from entering the "FROZEN"
state disappear from the cgroup's set of tasks.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using "def_bool n" is pointless, simply using bool here appears more
appropriate.
Further, retaining such options that don't have a prompt and aren't
selected by anything seems also at least questionable.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ingo said sparse_irq is some intrusive. need to make it selectable
to make it simple, remove irq_desc as parameter in some functions.
(ack, eoi, set_affinity).
may need to make member if irq_chip to take irq_desc, or struct irq later.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
but actually irq still needs to be less than NR_IRQS, because
interrupt[NR_IRQS] in entry.S.
need to enable per_cpu vector...
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This has been deprecated for years, the user space irqbalanced utility
works better with numa, has configurable policies, etc...
Signed-off-by: Yinghai Lu <yhlu.kernel@gmai.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.
Preallocate 32 irq_desc, and irq_desc() will try to get more.
( No change in functionality is expected anywhere, except the odd build
failure where we missed a code site or where a crossing commit itroduces
new irq_desc[] usage. )
v2: according to Eric, change get_irq_desc() to irq_desc()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Enable the use of the __mcount_loc infrastructure on x86_64 and i386.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Combine both generic and arch-specific parts of microcode into a
single module (arch-specific parts are config-dependent).
Also while we are at it, move arch-specific parts from microcode.h
into their respective arch-specific .c files.
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: "Peter Oruba" <peter.oruba@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The AMD IOMMU can generate interrupts for various reasons. This patch
adds the basic interrupt enabling infrastructure to the driver.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This bugzilla:
http://bugzilla.kernel.org/show_bug.cgi?id=11237
Documents a wide range of systems where the BIOS utilizes the first
64K of physical memory during suspend/resume and other hardware events.
Currently we reserve this memory on all AMI and Phoenix BIOS systems.
Life is too short to hunt subtle memory corruption problems like this,
so we try to be robust by default.
Still, allow this to be overriden: allow users who want that first 64K
of memory to be available to the kernel disable the quirk, via
CONFIG_X86_RESERVE_LOW_64K=n.
Also, allow the early reservation to overlap with other
early reservations.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There's no good reason why a resource_size_t shouldn't just be a
physical address, so simply redefine it in terms of phys_addr_t.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a kernel-wide "phys_addr_t" which is guaranteed to be able to hold
any physical address. By default it equals the word size of the
architecture, but a 32-bit architecture can set ARCH_PHYS_ADDR_T_64BIT
if it needs a 64-bit phys_addr_t.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Default the low memory corruption check to off, but make the default setting of
the memory_corruption_check kernel parameter a config parameter.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The corruption check is enabled in Kconfig by default, but disabled at runtime.
This patch adds several kernel parameters to control the corruption
check's behaviour; these are documented in kernel-parameters.txt.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some BIOSes have been observed to corrupt memory in the low 64k. This
change:
- Reserves all memory which does not have to be in that area, to
prevent it from being used as general memory by the kernel. Things
like the SMP trampoline are still in the memory, however.
- Clears the reserved memory so we can observe changes to it.
- Adds a function check_for_bios_corruption() which checks and reports on
memory becoming unexpectedly non-zero. Currently it's called in the
x86 fault handler, and the powermanagement debug output.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
HAVE_AOUT doesn't quite do the same thing as the recently removed
ARCH_SUPPORTS_AOUT config option. That was set even on platforms where
binfmt_aout isn't supported, although it's not entirely clear why.
So it's best just to introduce a new symbol, handled consistently with
other similar HAVE_xxx symbols; with a simple 'select' in the arch Kconfig.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This fixes a regression that was indirectly caused by commit
1184dc2ffe ("x86: modify Kconfig to allow
up to 4096 cpus").
Allowing 4k CPU's is not practical at this time, because we still have a
number of places that have several 'cpumask_t's on the stack, and a
4k-bit cpumask is 512 bytes of stack-space for each such variable. This
literally caused functions like 'smp_call_function_mask' to have a 2.5kB
stack frame, and several functions to have 2kB stackframes.
With an 8kB stack total, smashing the stack was simply much too likely.
At least bugzilla entry
http://bugzilla.kernel.org/show_bug.cgi?id=11342
was due to this.
The earlier commit to not inline load_module() into sys_init_module()
fixed the particular symptoms of this that Alan Brunelle saw in that
bugzilla entry, but the huge stack waste by cpumask_t's was the more
direct cause.
Some day we'll have allocation helpers that allocate large CPU masks
dynamically, but in the meantime we simply cannot allow cpumasks this
large.
Cc: Alan D. Brunelle <Alan.Brunelle@hp.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow x86 to support a built-in kernel command line. The built-in
command line can override the one provided by the boot loader, for
those cases where the boot loader is broken or it is difficult
to change the command line in the the boot loader.
H. Peter Anvin wrote:
> Ingo Molnar wrote:
>> Best would be to make it really apparent in the code that nothing
>> changes if this config option is not set. Preferably there should be
>> no extra code at all in that case.
>>
>
> I would like to see this:
[...Nested ifdefs...]
OK. This version changes absolutely nothing if CONFIG_CMDLINE_BOOL is not
set (the default). Also, no space is appended even when CONFIG_CMDLINE_BOOL
is set, but the builtin string is empty. This is less sloppy all the way
around, IMHO.
Note that I use the same option names as on other arches for
this feature.
[ mingo@elte.hu: build fix ]
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Adjust experimental tags in Kconfig, update config to notice that
i386/x86_64 is now single architecture.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.
Export the symbol to modules so lguest can use it.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With CONFIG_X86_PC, I can set CONFIG_SPARSEMEM=y.
With CONFIG_X86_GENERICARCH, CONFIG_SPARSEMEM depends on CONFIG_NUMA.
I'm using the patch below to enable sparsemem instead of flatmem.
System booted and is running.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU
on the x86 architecture.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch introduces microcode patch loading for AMD
processors. It is based on previous corresponding work
for Intel processors.
It hooks into the general patch loading module. Main
difference is that a container file format is used to hold
all patch data for multiple processors as well as an
equivalent CPU table, which comes seperately, as opposed
to Intel's microcode patching solution.
Kconfig and Makefile have been changed provice config
and build option for new source file.
Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Refactored code by introducing a two-module solution.
There is one general module in which vendor specific modules can hook into.
However, that is exclusive, there is only one vendor specific module
allowed at a time. A CPU vendor check makes sure only the correct
module for the underlying system gets called.
Functinally in terms of patch loading itself there are no changes. This
refactoring provides a basis for future implementations of other vendors'
patch loaders.
Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move mtrr.txt to the Documentation/x86/ subdirectory.
Add 00-INDEX to the Documentation/x86/ subdirectory.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, AMD IOMMU: include amd_iommu_last_bdf in device initialization
x86: fix IBM Summit based systems' phys_cpu_present_map on 32-bit kernels
x86, RDC321x: remove gpio.h complications
x86, RDC321x: add to mach-default
crashdump: fix undefined reference to `elfcorehdr_addr'
flag parameters: fix compile error of sys_epoll_create1
Implement get_user_pages_fast without locking in the fastpath on x86.
Do an optimistic lockless pagetable walk, without taking mmap_sem or any
page table locks or even mmap_sem. Page table existence is guaranteed by
turning interrupts off (combined with the fact that we're always looking
up the current mm, means we can do the lockless page table walk within the
constraints of the TLB shootdown design). Basically we can do this
lockless pagetable walk in a similar manner to the way the CPU's pagetable
walker does not have to take any locks to find present ptes.
This patch (combined with the subsequent ones to convert direct IO to use
it) was found to give about 10% performance improvement on a 2 socket 8
core Intel Xeon system running an OLTP workload on DB2 v9.5
"To test the effects of the patch, an OLTP workload was run on an IBM
x3850 M2 server with 2 processors (quad-core Intel Xeon processors at
2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing
runs with and without the patch resulted in an overall performance
benefit of ~9.8%. Correspondingly, oprofiles showed that samples from
__up_read and __down_read routines that is seen during thread contention
for system resources was reduced from 2.8% down to .05%. Monitoring the
/proc/vmstat output from the patched run showed that the counter for
fast_gup contained a very high number while the fast_gup_slow value was
zero."
(fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a
counter we had for the number of times the slowpath was invoked).
The main reason for the improvement is that DB2 has multiple threads each
issuing direct-IO. Direct-IO uses get_user_pages, and thus the threads
contend the mmap_sem cacheline, and can also contend on page table locks.
I would anticipate larger performance gains on larger systems, however I
think DB2 uses an adaptive mix of threads and processes, so it could be
that thread contention remains pretty constant as machine size increases.
In which case, we stuck with "only" a 10% gain.
The downside of using get_user_pages_fast is that if there is not a pte
with the correct permissions for the access, we end up falling back to
get_user_pages and so the get_user_pages_fast is a bit of extra work.
However this should not be the common case in most performance critical
code.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: Kconfig fix]
[akpm@linux-foundation.org: Makefile fix/cleanup]
[akpm@linux-foundation.org: warning fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch implements devices state save/restore before after kexec.
This patch together with features in kexec_jump patch can be used for
following:
- A simple hibernation implementation without ACPI support. You can kexec a
hibernating kernel, save the memory image of original system and shutdown
the system. When resuming, you restore the memory image of original system
via ordinary kexec load then jump back.
- Kernel/system debug through making system snapshot. You can make system
snapshot, jump back, do some thing and make another system snapshot.
- Cooperative multi-kernel/system. With kexec jump, you can switch between
several kernels/systems quickly without boot process except the first time.
This appears like swap a whole kernel/system out/in.
- A general method to call program in physical mode (paging turning
off). This can be used to invoke BIOS code under Linux.
The following user-space tools can be used with kexec jump:
- kexec-tools needs to be patched to support kexec jump. The patches
and the precompiled kexec can be download from the following URL:
source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10
- makedumpfile with patches are used as memory image saving tool, it
can exclude free pages from original kernel memory image file. The
patches and the precompiled makedumpfile can be download from the
following URL:
source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10
- An initramfs image can be used as the root file system of kexeced
kernel. An initramfs image built with "BuildRoot" can be downloaded
from the following URL:
initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz
All user space tools above are included in the initramfs image.
Usage example of simple hibernation:
1. Compile and install patched kernel with following options selected:
CONFIG_X86_32=y
CONFIG_RELOCATABLE=y
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_PM=y
CONFIG_HIBERNATION=y
CONFIG_KEXEC_JUMP=y
2. Build an initramfs image contains kexec-tool and makedumpfile, or
download the pre-built initramfs image, called rootfs.gz in
following text.
3. Prepare a partition to save memory image of original kernel, called
hibernating partition in following text.
4. Boot kernel compiled in step 1 (kernel A).
5. In the kernel A, load kernel compiled in step 1 (kernel B) with
/sbin/kexec. The shell command line can be as follow:
/sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000
--mem-max=0xffffff --initrd=rootfs.gz
6. Boot the kernel B with following shell command line:
/sbin/kexec -e
7. The kernel B will boot as normal kexec. In kernel B the memory
image of kernel A can be saved into hibernating partition as
follow:
jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='`
echo $jump_back_entry > kexec_jump_back_entry
cp /proc/vmcore dump.elf
Then you can shutdown the machine as normal.
8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
root file system.
9. In kernel C, load the memory image of kernel A as follow:
/sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf
10. Jump back to the kernel A as follow:
/sbin/kexec -e
Then, kernel A is resumed.
Implementation point:
To support jumping between two kernels, before jumping to (executing)
the new kernel and jumping back to the original kernel, the devices
are put into quiescent state, and the state of devices and CPU is
saved. After jumping back from kexeced kernel and jumping to the new
kernel, the state of devices and CPU are restored accordingly. The
devices/CPU state save/restore code of software suspend is called to
implement corresponding function.
Known issues:
- Because the segment number supported by sys_kexec_load is limited,
hibernation image with many segments may not be load. This is
planned to be eliminated by adding a new flag to sys_kexec_load to
make a image can be loaded with multiple sys_kexec_load invoking.
Now, only the i386 architecture is supported.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides an enhancement to kexec/kdump. It implements the
following features:
- Backup/restore memory used by the original kernel before/after
kexec.
- Save/restore CPU state before/after kexec.
The features of this patch can be used as a general method to call program in
physical mode (paging turning off). This can be used to call BIOS code under
Linux.
kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:
source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10
Usage example of calling some physical mode code and return:
1. Compile and install patched kernel with following options selected:
CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y
2. Build patched kexec-tool or download the pre-built one.
3. Build some physical mode executable named such as "phy_mode"
4. Boot kernel compiled in step 1.
5. Load physical mode executable with /sbin/kexec. The shell command
line can be as follow:
/sbin/kexec --load-preserve-context --args-none phy_mode
6. Call physical mode executable with following shell command line:
/sbin/kexec -e
Implementation point:
To support jumping without reserving memory. One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page). When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped. Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.
C ABI (calling convention) is used as communication protocol between
kernel and called code.
A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.
Now, only the i386 architecture is supported.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds functionality to the gpio-lib subsystem to make it
possible to enable the gpio-lib code even if the architecture code didn't
request to get it built in.
The archtitecture code does still need to implement the gpiolib accessor
functions in its asm/gpio.h file. This patch adds the implementations for
x86 and PPC.
With these changes it is possible to run generic GPIO expansion cards on
every architecture that implements the trivial wrapper functions. Support
for more architectures can easily be added.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In many cases, especially in networking, it can be beneficial to know at
compile time whether the architecture can do unaligned accesses efficiently.
This patch introduces a new Kconfig symbol
HAVE_EFFICIENT_UNALIGNED_ACCESS
for that purpose and adds it to the powerpc and x86 architectures. Also add
some documentation about alignment and networking, and especially one intended
use of this symbol.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ingo Molnar <mingo@elte.hu> [x86 architecture part]
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
