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* smp_call_function_single(): be slightly less stupidAndrew Morton2009-01-111-10/+3
| | | | | | | | | | | | | | | | | | | 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 <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* cpumask: smp_call_function_many()Rusty Russell2008-12-301-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: npiggin@suse.de Cc: axboe@kernel.dk
* Merge branch 'master' of ↵Rusty Russell2008-12-301-0/+2
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
| * Define smp_call_function_many for UPRusty Russell2008-12-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | 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 <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cpumask: add sysfs displays for configured and disabled cpu mapsMike Travis2008-12-191-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 be printed for all architectures. * 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 <travis@sgi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* cpumask: introduce new API, without changing anythingRusty Russell2008-11-061-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* softirq: Add support for triggering softirq work on softirqs.David S. Miller2008-10-171-1/+3
| | | | | | | | This is basically a genericization of Jens Axboe's block layer remote softirq changes. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Full conversion to early_initcall() interface, remove old interfaceEduard - Gabriel Munteanu2008-07-261-5/+0
| | | | | | | | | | | | | | | | 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 <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* generic-ipi: fix s390 build bugHeiko Carstens2008-07-041-1/+0
| | | | | | | | | | | | | | | | | | forgot to remove #include <linux/spinlock.h> 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 <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* on_each_cpu(): kill unused 'retry' parameterJens Axboe2008-06-261-2/+2
| | | | | | | | | It's not even passed on to smp_call_function() anymore, since that was removed. So kill it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* smp_call_function: get rid of the unused nonatomic/retry argumentJens Axboe2008-06-261-4/+4
| | | | | | | | It's never used and the comments refer to nonatomic and retry interchangably. So get rid of it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Add generic helpers for arch IPI function callsJens Axboe2008-06-261-2/+33
| | | | | | | | | | | | | | | | | 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" <Alan.Brunelle@hp.com> has contributed lots of fixes and suggestions as well. Also thanks to Paul E. McKenney <paulmck@linux.vnet.ibm.com> for reviewing RCU usage and getting rid of the data allocation fallback deadlock. Acked-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* x86: optimize lock prefix switching to run less frequentlyAndi Kleen2008-01-301-0/+2
| | | | | | | | | | | | | | | | | | | | | | 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 <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* KVM: fix !SMP build errorIngo Molnar2007-11-091-2/+5
| | | | | | | | | | | | 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 <mingo@elte.hu>
* smp_call_function_single() should be a macro on UPAl Viro2007-07-171-10/+8
| | | | | | | | | | | ... 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 <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SMP: Allow smp_call_function_single() to current cpuAvi Kivity2007-07-161-1/+6
| | | | | | | | This removes the requirement for callers to get_cpu() to check in simple cases. This patch is for !CONFIG_SMP. Cc: Andi Kleen <ak@suse.de> Signed-off-by: Avi Kivity <avi@qumranet.com>
* Let smp_call_function_single return -EBUSY on UPHeiko Carstens2007-05-171-4/+3
| | | | | | | | | | | | | 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 <heiko.carstens@de.ibm.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove hardcoding of hard_smp_processor_id on UP systemsFernando Luis Vazquez Cao2007-05-091-1/+0
| | | | | | | | | | | | | | | | | | | | 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 <fernando@oss.ntt.co.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Acked-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] declare smp_call_function_single in generic codeRandy Dunlap2006-12-071-0/+7
| | | | | | | | | | | | 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 <randy.dunlap@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] smp_call_function_single() cleanupAndrew Morton2006-09-261-0/+3
| | | | | | | | | | | | 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 <linux/smp.h>. Cc: Stephane Eranian <eranian@hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add smp_setup_processor_id()Andrew Morton2006-06-301-0/+2
| | | | | | | | | | | | | 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 <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Don't include linux/config.h from anywhere else in include/David Woodhouse2006-04-261-1/+0
| | | | Signed-off-by: David Woodhouse <dwmw2@infradead.org>
* [PATCH] cleanup smp_call_function UP buildCon Kolivas2006-03-261-1/+5
| | | | | | | | | | net/core/flow.c: In function 'flow_cache_flush': net/core/flow.c:299: warning: statement with no effect Signed-off-by: Con Kolivas <kernel@kolivas.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] on_each_cpu(): disable local interruptsAndrew Morton2006-03-221-14/+9
| | | | | | | | | | | | | | | | | | | 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 <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove bogus asm/bug.h includes.Al Viro2006-02-071-1/+0
| | | | | | | 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 <viro@zeniv.linux.org.uk>
* Revert "[NET]: Shut up warnings in net/core/flow.c"Linus Torvalds2005-11-231-7/+1
| | | | | | | | | | 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 <torvalds@osdl.org>
* [NET]: Shut up warnings in net/core/flow.cRussell King2005-11-221-1/+7
| | | | | | | | | | | | | | Not really a network problem, more a !SMP issue. net/core/flow.c:295: warning: statement with no effect flow.c:295: smp_call_function(flow_cache_flush_per_cpu, &info, 1, 0); Fix this by converting the macro to an inline function, which also increases the typechecking for !SMP builds. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert broken "statement with no effect" warning fixLinus Torvalds2005-07-281-16/+4
| | | | | | | | | | It may shut up gcc, but it also incorrectly changes the semantics of the smp_call_function() helpers. You can fix the warning other ways if you are interested (create another inline function that takes no arguments and returns zero), but preferably gcc just shouldn't complain about unused return values from statement expressions in the first place.
* [PATCH] alpha: fix "statement with no effect" warningsRichard Henderson2005-07-281-4/+16
| | | | | | | | | | | | | Apparently gcc 4.0 complains about "({ 0; });", which leads to -Werror breakage in one of the alpha oprofile modules. One might could argue that this is a gcc bug, in that statement-expressions should be considered to be function-like rather than statement-like for the purposes of this warning. But it's just as easy to use an inline function in the first place, side-stepping the issue. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] smp_processor_id() cleanupIngo Molnar2005-06-211-24/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements a number of smp_processor_id() cleanup ideas that Arjan van de Ven and I came up with. The previous __smp_processor_id/_smp_processor_id/smp_processor_id API spaghetti was hard to follow both on the implementational and on the usage side. Some of the complexity arose from picking wrong names, some of the complexity comes from the fact that not all architectures defined __smp_processor_id. In the new code, there are two externally visible symbols: - smp_processor_id(): debug variant. - raw_smp_processor_id(): nondebug variant. Replaces all existing uses of _smp_processor_id() and __smp_processor_id(). Defined by every SMP architecture in include/asm-*/smp.h. There is one new internal symbol, dependent on DEBUG_PREEMPT: - debug_smp_processor_id(): internal debug variant, mapped to smp_processor_id(). Also, i moved debug_smp_processor_id() from lib/kernel_lock.c into a new lib/smp_processor_id.c file. All related comments got updated and/or clarified. I have build/boot tested the following 8 .config combinations on x86: {SMP,UP} x {PREEMPT,!PREEMPT} x {DEBUG_PREEMPT,!DEBUG_PREEMPT} I have also build/boot tested x64 on UP/PREEMPT/DEBUG_PREEMPT. (Other architectures are untested, but should work just fine.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+139
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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