17 Jun, 2011
1 commit
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There is a problem that kdump(2nd kernel) sometimes hangs up due
to a pending IPI from 1st kernel. Kernel panic occurs because IPI
comes before call_single_queue is initialized.To fix the crash, rename init_call_single_data() to call_function_init()
and call it in start_kernel() so that call_single_queue can be
initialized before enabling interrupts.The details of the crash are:
(1) 2nd kernel boots up
(2) A pending IPI from 1st kernel comes when irqs are first enabled
in start_kernel().(3) Kernel tries to handle the interrupt, but call_single_queue
is not initialized yet at this point. As a result, in the
generic_smp_call_function_single_interrupt(), NULL pointer
dereference occurs when list_replace_init() tries to access
&q->list.next.Therefore this patch changes the name of init_call_single_data()
to call_function_init() and calls it before local_irq_enable()
in start_kernel().Signed-off-by: Takao Indoh
Reviewed-by: WANG Cong
Acked-by: Neil Horman
Acked-by: Vivek Goyal
Acked-by: Peter Zijlstra
Cc: Milton Miller
Cc: Jens Axboe
Cc: Paul E. McKenney
Cc: kexec@lists.infradead.org
Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com
Signed-off-by: Ingo Molnar
26 May, 2011
1 commit
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Now that powerpc has removed its use of MSG_ALL_BUT_SELF and MSG_ALL
all these MSG_ flags are unused.Signed-off-by: Milton Miller
Signed-off-by: Benjamin Herrenschmidt
23 Mar, 2011
2 commits
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Commit 34db18a054c6 ("smp: move smp setup functions to kernel/smp.c")
causes this build error on s390 because of a missing init.h include:CC arch/s390/kernel/asm-offsets.s
In file included from /home2/heicarst/linux-2.6/arch/s390/include/asm/spinlock.h:14:0,
from include/linux/spinlock.h:87,
from include/linux/seqlock.h:29,
from include/linux/time.h:8,
from include/linux/timex.h:56,
from include/linux/sched.h:57,
from arch/s390/kernel/asm-offsets.c:10:
include/linux/smp.h:117:20: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'setup_nr_cpu_ids'
include/linux/smp.h:118:20: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'smp_init'Fix it by adding the include statement.
Signed-off-by: Heiko Carstens
Acked-by: WANG Cong
Signed-off-by: Linus Torvalds -
Move setup_nr_cpu_ids(), smp_init() and some other SMP boot parameter
setup functions from init/main.c to kenrel/smp.c, saves some #ifdef
CONFIG_SMP.Signed-off-by: WANG Cong
Cc: Rakib Mullick
Cc: David Howells
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Tejun Heo
Cc: Arnd Bergmann
Cc: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Oct, 2010
1 commit
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Typedef the pointer to the function to be called by smp_call_function() and
friends:typedef void (*smp_call_func_t)(void *info);
as it is used in a fair number of places.
Signed-off-by: David Howells
cc: linux-arch@vger.kernel.org
07 Mar, 2010
1 commit
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smp: Fix documentation.
Fix documentation in include/linux/smp.h: smp_processor_id()
Signed-off-by: Rakib Mullick
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Nov, 2009
1 commit
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Andrew points out that acpi-cpufreq uses cpumask_any, when it really
would prefer to use the same CPU if possible (to avoid an IPI). In
general, this seems a good idea to offer.[ tglx: Documented selection preference and Inlined the UP case to
avoid the copy of smp_call_function_single() and the extra
EXPORT ]Signed-off-by: Rusty Russell
Cc: Ingo Molnar
Cc: Venkatesh Pallipadi
Cc: Len Brown
Cc: Zhao Yakui
Cc: Dave Jones
Cc: Thomas Gleixner
Cc: Mike Galbraith
Cc: "Zhang, Yanmin"
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner
24 Sep, 2009
1 commit
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Everyone is now using smp_call_function_many().
Signed-off-by: Rusty Russell
17 Jun, 2009
1 commit
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put_cpu_no_resched() is an optimization of put_cpu() which unfortunately
can cause high latencies.The nfs iostats code uses put_cpu_no_resched() in a code sequence where a
reschedule request caused by an interrupt between the get_cpu() and the
put_cpu_no_resched() can delay the reschedule for at least HZ.The other users of put_cpu_no_resched() optimize correctly in interrupt
code, but there is no real harm in using the put_cpu() function which is
an alias for preempt_enable(). The extra check of the preemmpt count is
not as critical as the potential source of missing a reschedule.Debugged in the preempt-rt tree and verified in mainline.
Impact: remove a high latency source
[akpm@linux-foundation.org: build fix]
Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Cc: Tony Luck
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Mar, 2009
2 commits
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Impact: cleanup, no code changed
Remove an ugly #ifdef CONFIG_SMP from panic(), by providing
an smp_send_stop() wrapper on UP too.LKML-Reference:
Signed-off-by: Ingo Molnar
25 Feb, 2009
1 commit
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Oleg noticed that we don't strictly need CSD_FLAG_WAIT, rework
the code so that we can use CSD_FLAG_LOCK for both purposes.Signed-off-by: Peter Zijlstra
Cc: Oleg Nesterov
Cc: Linus Torvalds
Cc: Nick Piggin
Cc: Jens Axboe
Cc: "Paul E. McKenney"
Cc: Rusty Russell
Signed-off-by: Ingo Molnar
06 Feb, 2009
2 commits
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This function should be provided on UP too.
Signed-off-by: Ingo Molnar
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Impact: cleanup
disable_ioapic_setup() in init/main.c is ugly as the function is
x86-specific. The #ifdef inline prototype there is ugly too.Replace it with a generic arch_disable_smp_support() function - which
has a weak alias for non-x86 architectures and for non-ioapic x86 builds.Signed-off-by: Ingo Molnar
11 Jan, 2009
1 commit
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If you do
smp_call_function_single(expression-with-side-effects, ...)
then expression-with-side-effects never gets evaluated on UP builds.
As always, implementing it in C is the correct thing to do.
While we're there, uninline it for size and possible header dependency
reasons.And create a new kernel/up.c, as a place in which to put
uniprocessor-specific code and storage. It should mirror kernel/smp.c.Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
30 Dec, 2008
2 commits
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Impact: Implementation change to remove cpumask_t from stack.
Actually change smp_call_function_mask() to smp_call_function_many().
We avoid cpumasks on the stack in this version.(S390 has its own version, but that's going away apparently).
We have to do some dancing to figure out if 0 or 1 other cpus are in
the mask supplied and the online mask without allocating a tmp
cpumask. It's still fairly cheap.We allocate the cpumask at the end of the call_function_data
structure: if allocation fails we fallback to smp_call_function_single
rather than using the baroque quiescing code (which needs a cpumask on
stack).(Thanks to Hiroshi Shimamoto for spotting several bugs in previous versions!)
Signed-off-by: Rusty Russell
Signed-off-by: Mike Travis
Cc: Hiroshi Shimamoto
Cc: npiggin@suse.de
Cc: axboe@kernel.dk
19 Dec, 2008
1 commit
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Impact: add new sysfs files.
Add sysfs files "kernel_max" and "offline" to display the max CPU index
allowed (NR_CPUS-1), and the map of cpus that are offline.Cpus can be offlined via HOTPLUG, disabled by the BIOS ACPI tables, or
if they exceed the number of cpus allowed by the NR_CPUS config option,
or the "maxcpus=NUM" kernel start parameter.The "possible_cpus=NUM" parameter can also extend the number of possible
cpus allowed, in which case the cpus not present at startup will be
in the offline state. (These cpus can be HOTPLUGGED ON after system
startup [pending a follow-on patch to provide the capability via the
/sys/devices/sys/cpu/cpuN/online mechanism to bring them online.])By design, the "offlined cpus > possible cpus" display will always
use the following formats:* all possible cpus online: "x$" or "x-y$"
* some possible cpus offline: ".*,x$" or ".*,x-y$"where:
x == number of possible cpus (nr_cpu_ids); and
y == number of cpus >= NR_CPUS or maxcpus (if y > x).One use of this feature is for distros to select (or configure) the
appropriate kernel to install for the resident system.Notes:
* cpus offlined possible cpus will only be printed for arches that
set 'total_cpus' [X86 only in this patch].Based on tip/cpus4096 + .../rusty/linux-2.6-for-ingo.git/master +
x86-only-patches sent 12/15.Signed-off-by: Mike Travis
Signed-off-by: Rusty Russell
16 Dec, 2008
1 commit
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Otherwise those using it in transition patches (eg. kvm) can't compile
with CONFIG_SMP=n:arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function 'make_all_cpus_request':
arch/x86/kvm/../../../virt/kvm/kvm_main.c:380: error: implicit declaration of function 'smp_call_function_many'Signed-off-by: Rusty Russell
Signed-off-by: Linus Torvalds
06 Nov, 2008
1 commit
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Impact: introduce new APIs
We want to deprecate cpumasks on the stack, as we are headed for
gynormous numbers of CPUs. Eventually, we want to head towards an
undefined 'struct cpumask' so they can never be declared on stack.1) New cpumask functions which take pointers instead of copies.
(cpus_* -> cpumask_*)2) Several new helpers to reduce requirements for temporary cpumasks
(cpumask_first_and, cpumask_next_and, cpumask_any_and)3) Helpers for declaring cpumasks on or offstack for large NR_CPUS
(cpumask_var_t, alloc_cpumask_var and free_cpumask_var)4) 'struct cpumask' for explicitness and to mark new-style code.
5) Make iterator functions stop at nr_cpu_ids (a runtime constant),
not NR_CPUS for time efficiency and for smaller dynamic allocations
in future.6) cpumask_copy() so we can allocate less than a full cpumask eventually
(for alloc_cpumask_var), and so we can eliminate the 'struct cpumask'
definition eventually.7) work_on_cpu() helper for doing task on a CPU, rather than saving old
cpumask for current thread and manipulating it.8) smp_call_function_many() which is smp_call_function_mask() except
taking a cpumask pointer.Note that this patch simply introduces the new functions and leaves
the obsolescent ones in place. This is to simplify the transition
patches.Signed-off-by: Rusty Russell
Signed-off-by: Ingo Molnar
17 Oct, 2008
1 commit
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This is basically a genericization of Jens Axboe's block layer
remote softirq changes.Signed-off-by: David S. Miller
Signed-off-by: Jens Axboe
27 Jul, 2008
1 commit
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A previous patch added the early_initcall(), to allow a cleaner hooking of
pre-SMP initcalls. Now we remove the older interface, converting all
existing users to the new one.[akpm@linux-foundation.org: cleanups]
[akpm@linux-foundation.org: build fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
[kosaki.motohiro@jp.fujitsu.com: warning fix]
Signed-off-by: Eduard - Gabriel Munteanu
Cc: Tom Zanussi
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2008
1 commit
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forgot to remove #include from linux/smp.h while
fixing the original s390 build bug.Patch below fixes this build bug caused by header inclusion dependencies:
CC kernel/timer.o
In file included from include/linux/spinlock.h:87,
from include/linux/smp.h:11,
from include/linux/kernel_stat.h:4,
from kernel/timer.c:22:
include/asm/spinlock.h: In function '__raw_spin_lock':
include/asm/spinlock.h:69: error: implicit declaration of function 'smp_processor_id'Signed-off-by: Heiko Carstens
Signed-off-by: Ingo Molnar
26 Jun, 2008
3 commits
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It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.Acked-by: Jeremy Fitzhardinge
Reviewed-by: Paul E. McKenney
Signed-off-by: Jens Axboe -
It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.Acked-by: Jeremy Fitzhardinge
Signed-off-by: Jens Axboe -
This adds kernel/smp.c which contains helpers for IPI function calls. In
addition to supporting the existing smp_call_function() in a more efficient
manner, it also adds a more scalable variant called smp_call_function_single()
for calling a given function on a single CPU only.The core of this is based on the x86-64 patch from Nick Piggin, lots of
changes since then. "Alan D. Brunelle" has
contributed lots of fixes and suggestions as well. Also thanks to
Paul E. McKenney for reviewing RCU usage
and getting rid of the data allocation fallback deadlock.Acked-by: Ingo Molnar
Reviewed-by: Paul E. McKenney
Signed-off-by: Jens Axboe
30 Jan, 2008
1 commit
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On VMs implemented using JITs that cache translated code changing the lock
prefixes is a quite costly operation that forces the JIT to throw away and
retranslate a lot of code.Previously a SMP kernel would rewrite the locks once for each CPU which
is quite unnecessary. This patch changes the code to never switch at boot in
the normal case (SMP kernel booting with >1 CPU) or only once for SMP kernel
on UP.This makes a significant difference in boot up performance on AMD SimNow!
Also I expect it to be a little faster on native systems too because a smp
switch does a lot of text_poke()s which each synchronize the pipeline.v1->v2: Rename max_cpus
v1->v2: Fix off by one in UP check (Thomas Gleixner)Signed-off-by: Andi Kleen
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
10 Nov, 2007
1 commit
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fix a !SMP build error:
drivers/kvm/kvm_main.c: In function 'kvm_flush_remote_tlbs':
drivers/kvm/kvm_main.c:220: error: implicit declaration of function 'smp_call_function_mask'(and also avoid unused function warning related to up_smp_call_function()
not making use of the 'func' parameter.)Signed-off-by: Ingo Molnar
18 Jul, 2007
1 commit
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... or we end up with header include order problems from hell.
E.g. on m68k this is 100% fatal - local_irq_enable() there
wants preempt_count(), which wants task_struct fields, which
we won't have when we are in smp.h pulled from sched.h.Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
16 Jul, 2007
1 commit
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This removes the requirement for callers to get_cpu() to check in simple
cases. This patch is for !CONFIG_SMP.Cc: Andi Kleen
Signed-off-by: Avi Kivity
17 May, 2007
1 commit
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All architectures that have an implementation of smp_call_function_single
let it return -EBUSY if it is asked to execute func on the current cpu.
(akpm: except for x86_64). Therefore the UP version must always return
-EBUSY.[akpm@linux-foundation.org: build fix]
Signed-off-by: Heiko Carstens
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 May, 2007
1 commit
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With the advent of kdump, the assumption that the boot CPU when booting an UP
kernel is always the CPU with a particular hardware ID (often 0) (usually
referred to as BSP on some architectures) is not valid anymore. The reason
being that the dump capture kernel boots on the crashed CPU (the CPU that
invoked crash_kexec), which may be or may not be that particular CPU.Move definition of hard_smp_processor_id for the UP case to
architecture-specific code ("asm/smp.h") where it belongs, so that each
architecture can provide its own implementation.Signed-off-by: Fernando Luis Vazquez Cao
Cc: "Luck, Tony"
Acked-by: Andi Kleen
Cc: "Eric W. Biederman"
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
1 commit
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smp_call_function_single() needs to be visible in non-SMP builds, to fix:
arch/x86_64/kernel/vsyscall.c:283: warning: implicit declaration of function 'smp_call_function_single'
Signed-off-by: Randy Dunlap
Cc: Ingo Molnar
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Sep, 2006
1 commit
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If we're going to implement smp_call_function_single() on three architecture
with the same prototype then it should have a declaration in a
non-arch-specific header file.Move it into .
Cc: Stephane Eranian
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Jul, 2006
1 commit
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Presently, smp_processor_id() isn't necessarily set up until setup_arch().
But it's used in boot_cpu_init() and printk() and perhaps in other places,
prior to setup_arch() being called.So provide a new smp_setup_processor_id() which is called before anything
else, wire it up for Voyager (which boots on a CPU other than #0, and broke).Cc: James Bottomley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Apr, 2006
1 commit
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Signed-off-by: David Woodhouse
27 Mar, 2006
1 commit
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net/core/flow.c: In function 'flow_cache_flush':
net/core/flow.c:299: warning: statement with no effectSigned-off-by: Con Kolivas
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Mar, 2006
1 commit
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When on_each_cpu() runs the callback on other CPUs, it runs with local
interrupts disabled. So we should run the function with local interrupts
disabled on this CPU, too.And do the same for UP, so the callback is run in the same environment on both
UP and SMP. (strictly it should do preempt_disable() too, but I think
local_irq_disable is sufficiently equivalent).Also uninlines on_each_cpu(). softirq.c was the most appropriate file I could
find, but it doesn't seem to justify creating a new file.Oh, and fix up that comment over (under?) x86's smp_call_function(). It
drives me nuts.Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Feb, 2006
1 commit
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A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early). Removed.Signed-off-by: Al Viro
24 Nov, 2005
1 commit
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This reverts commit af2b4079ab154bd12e8c12b02db5f31b31babe63
Changing the #define to an inline function breaks on non-SMP builds,
since wuite a few places in the kernel do not implement the ipi handler
when compiling for UP.Signed-off-by: Linus Torvalds
