kernel/linux.git/include/linux/spinlock_api_up.h, branch v7.0-rc7

compiler-context-analysis: Remove __cond_lock() function-like helper

2026-01-05T15:43:33+00:00

As discussed in [1], removing __cond_lock() will improve the readability of trylock code. Now that Sparse context tracking support has been removed, we can also remove __cond_lock(). Change existing APIs to either drop __cond_lock() completely, or make use of the __cond_acquires() function attribute instead. In particular, spinlock and rwlock implementations required switching over to inline helpers rather than statement-expressions for their trylock_* variants. Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20250207082832.GU7145@noisy.programming.kicks-ass.net/ [1] Link: https://patch.msgid.link/20251219154418.3592607-25-elver@google.com

locking/rwlock, spinlock: Support Clang's context analysis

2026-01-05T15:43:28+00:00

Add support for Clang's context analysis for raw_spinlock_t, spinlock_t, and rwlock. This wholesale conversion is required because all three of them are interdependent. To avoid warnings in constructors, the initialization functions mark a lock as acquired when initialized before guarded variables. The test verifies that common patterns do not generate false positives. Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-9-elver@google.com

locking: Detect includes rwlock.h outside of spinlock.h

2022-09-15T14:14:02+00:00

From: Michael S. Tsirkin The check for __LINUX_SPINLOCK_H within rwlock.h (and other files) detects the direct include of the header file if it is at the very beginning of the include section. If it is listed later then chances are high that spinlock.h was already included (including rwlock.h) and the additional listing of rwlock.h will not cause any failure. On PREEMPT_RT this additional rwlock.h will lead to compile failures since it uses a different rwlock implementation. Add __LINUX_INSIDE_SPINLOCK_H to spinlock.h and check for this instead of __LINUX_SPINLOCK_H to detect wrong includes. This will help detect direct includes of rwlock.h with without PREEMPT_RT enabled. [ bigeasy: add remaining __LINUX_SPINLOCK_H user and rewrite commit description. ] Signed-off-by: Michael S. Tsirkin Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/YweemHxJx7O8rjBx@linutronix.de

locking/rwlocks: introduce write_lock_nested

2022-01-22T06:33:37+00:00

In preparation for converting bit_spin_lock to rwlock in zsmalloc so that multiple writers of zspages can run at the same time but those zspages are supposed to be different zspage instance. Thus, it's not deadlock. This patch adds write_lock_nested to support the case for LOCKDEP. [minchan@kernel.org: fix write_lock_nested for RT] Link: https://lkml.kernel.org/r/YZfrMTAXV56HFWJY@google.com [bigeasy@linutronix.de: fixup write_lock_nested() implementation] Link: https://lkml.kernel.org/r/20211123170134.y6xb7pmpgdn4m3bn@linutronix.de Link: https://lkml.kernel.org/r/20211115185909.3949505-8-minchan@kernel.org Signed-off-by: Minchan Kim Signed-off-by: Sebastian Andrzej Siewior Acked-by: Peter Zijlstra (Intel) Acked-by: Sebastian Andrzej Siewior Tested-by: Sebastian Andrzej Siewior Cc: Mike Galbraith Cc: Sergey Senozhatsky Cc: Thomas Gleixner Cc: Naresh Kamboju Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locking/spinlocks: Remove the unused spin_lock_bh_nested() API

2017-01-12T08:33:39+00:00

The spin_lock_bh_nested() API is defined but is not used anywhere in the kernel. So all spin_lock_bh_nested() and related APIs are now removed. Signed-off-by: Waiman Long Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1483975612-16447-1-git-send-email-longman@redhat.com Signed-off-by: Ingo Molnar

spinlock: Add spin_lock_bh_nested()

2015-01-03T19:32:57+00:00

Signed-off-by: Thomas Graf Signed-off-by: David S. Miller

locking: Optimize lock_bh functions

2014-01-13T12:47:36+00:00

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 Signed-off-by: Peter Zijlstra Cc: jacob.jun.pan@linux.intel.com Cc: Mike Galbraith Cc: hpa@zytor.com Cc: Arjan van de Ven Cc: lenb@kernel.org Cc: rjw@rjwysocki.net Cc: rui.zhang@intel.com Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

locking: Cleanup the name space completely

2009-12-14T22:55:33+00:00

Make the name space hierarchy of locking functions consistent: raw_spin* -> _raw_spin* -> __raw_spin* No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: Ingo Molnar

locking: Implement new raw_spinlock

2009-12-14T22:55:32+00:00

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 Acked-by: Peter Zijlstra Acked-by: Ingo Molnar

include/linux/: Spelling fixes

2008-02-03T15:45:46+00:00

Signed-off-by: Joe Perches Signed-off-by: Adrian Bunk