aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/spinlock_api_smp.h
Commit message (Collapse)AuthorAge
* locking: Optimize lock_bh functionsPeter Zijlstra2014-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently all _bh_ lock functions do two preempt_count operations: local_bh_disable(); preempt_disable(); and for the unlock: preempt_enable_no_resched(); local_bh_enable(); Since its a waste of perfectly good cycles to modify the same variable twice when you can do it in one go; use the new __local_bh_{dis,en}able_ip() functions that allow us to provide a preempt_count value to add/sub. So define SOFTIRQ_LOCK_OFFSET as the offset a _bh_ lock needs to add/sub to be done in one go. As a bonus it gets rid of the preempt_enable_no_resched() usage. This reduces a 1000 loops of: spin_lock_bh(&bh_lock); spin_unlock_bh(&bh_lock); from 53596 cycles to 51995 cycles. I didn't do enough measurements to say for absolute sure that the result is significant but the the few runs I did for each suggest it is so. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: jacob.jun.pan@linux.intel.com Cc: Mike Galbraith <bitbucket@online.de> Cc: hpa@zytor.com Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: lenb@kernel.org Cc: rjw@rjwysocki.net Cc: rui.zhang@intel.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* spinlock_api_smp.h: fix preprocessor commentsChen Gang2013-06-19
| | | | | | | Correct the related comments for '#ifdef ... #endif'. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* locking/kconfig: Simplify INLINE_SPIN_UNLOCK usageRaghavendra K T2012-03-23
| | | | | | | | | | | | | | | | | | | | | | | Get rid of INLINE_SPIN_UNLOCK entirely replacing it with UNINLINE_SPIN_UNLOCK instead of the reverse meaning. Whoever wants to change the default spinlock inlining behavior and uninline the spinlocks for some weird reason, such as spinlock debugging, paravirt etc. can now all just select UNINLINE_SPIN_UNLOCK Original discussion at: https://lkml.org/lkml/2012/3/21/357 Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: linux-mips@linux-mips.org Link: http://lkml.kernel.org/r/20120322095502.30866.75756.sendpatchset@codeblue [ tidied up the changelog a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* locking: Cleanup the name space completelyThomas Gleixner2009-12-14
| | | | | | | | | | | | Make the name space hierarchy of locking functions consistent: raw_spin* -> _raw_spin* -> __raw_spin* No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
* locking: Further name space cleanupsThomas Gleixner2009-12-14
| | | | | | | | | | | | | | | The name space hierarchy for the internal lock functions is now a bit backwards. raw_spin* functions map to _spin* which use __spin*, while we would like to have _raw_spin* and __raw_spin*. _raw_spin* is already used by lock debugging, so rename those funtions to do_raw_spin* to free up the _raw_spin* name space. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
* locking: Implement new raw_spinlockThomas Gleixner2009-12-14
| | | | | | | | | | | | | | | | Now that the raw_spin name space is freed up, we can implement raw_spinlock and the related functions which are used to annotate the locks which are not converted to sleeping spinlocks in preempt-rt. A side effect is that only such locks can be used with the low level lock fsunctions which circumvent lockdep. For !rt spin_* functions are mapped to the raw_spin* implementations. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
* locking: Separate rwlock api from spinlock apiThomas Gleixner2009-12-14
| | | | | | | | | | | | Move the rwlock smp api defines and functions into a separate header file. Makes the -rt selection simpler and less intrusive. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
* locking: Make inlining decision Kconfig basedThomas Gleixner2009-11-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the selection of which lock functions are inlined based on defines in arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION Despite of the name __always_inline__* the lock functions can be built out of line depending on config options. Also if the arch does not set some inline defines the generic code might set them; again depending on config options. This makes it unnecessary hard to figure out when and which lock functions are inlined. Aside of that it makes it way harder and messier for -rt to manipulate the lock functions. Convert the inlining decision to CONFIG switches. Each lock function is inlined depending on CONFIG_INLINE_*. The configs implement the existing dependencies. The architecture code can select ARCH_INLINE_* to signal that it wants the corresponding lock function inlined. ARCH_INLINE_* is necessary as Kconfig ignores "depends on" restrictions when a config element is selected. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20091109151428.504477141@linutronix.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
* locking: Simplify spinlock inliningHeiko Carstens2009-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For !DEBUG_SPINLOCK && !PREEMPT && SMP the spin_unlock() functions were always inlined by using special defines which would call the __raw* functions. The out-of-line variants for these functions would be generated anyway. Use the new per unlock/locking variant mechanism to force inlining of the unlock functions like before. This is not a functional change, we just get rid of one additional way to force inlining. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Horst Hartmann <horsth@linux.vnet.ibm.com> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <20090831124418.848735034@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* locking: Allow arch-inlined spinlocksHeiko Carstens2009-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows an architecture to specify per lock variant if the locking code should be kept out-of-line or inlined. If an architecure wants out-of-line locking code no change is needed. To force inlining of e.g. spin_lock() the line: #define __always_inline__spin_lock needs to be added to arch/<...>/include/asm/spinlock.h If CONFIG_DEBUG_SPINLOCK or CONFIG_GENERIC_LOCKBREAK are defined the per architecture defines are (partly) ignored and still out-of-line spinlock code will be generated. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Horst Hartmann <horsth@linux.vnet.ibm.com> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <20090831124418.375299024@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* locking: Move spinlock function bodies to header fileHeiko Carstens2009-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | Move spinlock function bodies to header file by creating a static inline version of each variant. Use the inline version on the out-of-line code. This shouldn't make any difference besides that the spinlock code can now be used to generate inlined spinlock code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Horst Hartmann <horsth@linux.vnet.ibm.com> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <20090831124417.859022429@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* lockdep: spin_lock_nest_lock()Peter Zijlstra2008-08-11
| | | | | | | | | | | | | Expose the new lock protection lock. This can be used to annotate places where we take multiple locks of the same class and avoid deadlocks by always taking another (top-level) lock first. NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [PATCH] lockdep: spin_lock_irqsave_nested()Arjan van de Ven2006-11-25
| | | | | | | | | | | | | | | Introduce spin_lock_irqsave_nested(); implementation from: http://lkml.org/lkml/2006/6/1/122 Patch from: http://lkml.org/lkml/2006/9/13/258 [akpm@osdl.org: two compile fixes] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Jiri Kosina <jikos@jikos.cz> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Make spinlock/rwlock annotations more accurate by using parameters, ↵Josh Triplett2006-09-29
| | | | | | | | | | | | | | | | | | | not types The lock annotations used on spinlocks and rwlocks currently use __{acquires,releases}(spinlock_t) and __{acquires,releases}(rwlock_t), respectively. This loses the information of which lock actually got acquired or released, and assumes a different type for the parameter of __acquires and __releases than the rest of the kernel. While the current implementations of __acquires and __releases throw away their argument, this will not always remain the case. Change this to use the lock parameter instead, to preserve this information and increase consistency in usage of __acquires and __releases. Signed-off-by: Josh Triplett <josh@freedesktop.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: prove spinlock rwlock locking correctnessIngo Molnar2006-07-03
| | | | | | | | | | Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] spinlock consolidationIngo Molnar2005-09-10
This patch (written by me and also containing many suggestions of Arjan van de Ven) does a major cleanup of the spinlock code. It does the following things: - consolidates and enhances the spinlock/rwlock debugging code - simplifies the asm/spinlock.h files - encapsulates the raw spinlock type and moves generic spinlock features (such as ->break_lock) into the generic code. - cleans up the spinlock code hierarchy to get rid of the spaghetti. Most notably there's now only a single variant of the debugging code, located in lib/spinlock_debug.c. (previously we had one SMP debugging variant per architecture, plus a separate generic one for UP builds) Also, i've enhanced the rwlock debugging facility, it will now track write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too. All locks have lockup detection now, which will work for both soft and hard spin/rwlock lockups. The arch-level include files now only contain the minimally necessary subset of the spinlock code - all the rest that can be generalized now lives in the generic headers: include/asm-i386/spinlock_types.h | 16 include/asm-x86_64/spinlock_types.h | 16 I have also split up the various spinlock variants into separate files, making it easier to see which does what. The new layout is: SMP | UP ----------------------------|----------------------------------- asm/spinlock_types_smp.h | linux/spinlock_types_up.h linux/spinlock_types.h | linux/spinlock_types.h asm/spinlock_smp.h | linux/spinlock_up.h linux/spinlock_api_smp.h | linux/spinlock_api_up.h linux/spinlock.h | linux/spinlock.h /* * here's the role of the various spinlock/rwlock related include files: * * on SMP builds: * * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the * initializers * * linux/spinlock_types.h: * defines the generic type and initializers * * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel * implementations, mostly inline assembly code * * (also included on UP-debug builds:) * * linux/spinlock_api_smp.h: * contains the prototypes for the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. * * on UP builds: * * linux/spinlock_type_up.h: * contains the generic, simplified UP spinlock type. * (which is an empty structure on non-debug builds) * * linux/spinlock_types.h: * defines the generic type and initializers * * linux/spinlock_up.h: * contains the __raw_spin_*()/etc. version of UP * builds. (which are NOPs on non-debug, non-preempt * builds) * * (included on UP-non-debug builds:) * * linux/spinlock_api_up.h: * builds the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. */ All SMP and UP architectures are converted by this patch. arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should be mostly fine. From: Grant Grundler <grundler@parisc-linux.org> Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU). Builds 32-bit SMP kernel (not booted or tested). I did not try to build non-SMP kernels. That should be trivial to fix up later if necessary. I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids some ugly nesting of linux/*.h and asm/*.h files. Those particular locks are well tested and contained entirely inside arch specific code. I do NOT expect any new issues to arise with them. If someone does ever need to use debug/metrics with them, then they will need to unravel this hairball between spinlocks, atomic ops, and bit ops that exist only because parisc has exactly one atomic instruction: LDCW (load and clear word). From: "Luck, Tony" <tony.luck@intel.com> ia64 fix Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjanv@infradead.org> Signed-off-by: Grant Grundler <grundler@parisc-linux.org> Cc: Matthew Wilcox <willy@debian.org> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se> Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>