linux.git/include/linux/mutex.h, branch v7.1-rc3

locking/mutex: Add context analysis

2026-03-08T10:06:53+00:00

Add compiler context analysis annotations.

Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260121111213.745353747@infradead.org

locking/mutex: Remove the list_head from struct mutex

2026-03-08T10:06:52+00:00

Instead of embedding a list_head in struct mutex, store a pointer to
the first waiter.  The list of waiters remains a doubly linked list so
we can efficiently add to the tail of the list, remove from the front
(or middle) of the list.

Some of the list manipulation becomes more complicated, but it's a
reasonable tradeoff on the slow paths to shrink data structures which
embed a mutex like struct file.

Some of the debug checks have to be deleted because there's no equivalent
to checking them in the new scheme (eg an empty waiter->list now means
that it is the only waiter, not that the waiter is no longer on the list).

Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260305195545.3707590-4-willy@infradead.org

locking/mutex: Add killable flavor to guard definitions

2026-02-23T10:19:16+00:00

The mutex guard family defines _try and _intr variants but is missing
the killable one.

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260217191512.1180151-4-dave@stgolabs.net

locking/mutex: Fix wrong comment for CONFIG_DEBUG_LOCK_ALLOC

2026-02-23T10:19:16+00:00

... that endif block should be CONFIG_DEBUG_LOCK_ALLOC, not
CONFIG_LOCKDEP.

Fixes: 51d7a054521d ("locking/mutex: Redo __mutex_init() to reduce generated code size")
Signed-off-by: Davidlohr Bueso 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260217191512.1180151-3-dave@stgolabs.net

locking/mutex: Rename mutex_init_lockep()

2026-02-23T10:19:15+00:00

Typo, this wants to be _lockdep().

Fixes: 51d7a054521d ("locking/mutex: Redo __mutex_init() to reduce generated code size")
Signed-off-by: Davidlohr Bueso 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260217191512.1180151-2-dave@stgolabs.net

compiler-context-analysis: Remove __assume_ctx_lock from initializers

2026-01-28T19:45:25+00:00

Remove __assume_ctx_lock() from lock initializers.

Implicitly asserting an active context during initialization caused
false-positive double-lock errors when acquiring a lock immediately after its
initialization. Moving forward, guarded member initialization must either:

	1. Use guard(type_init)(&lock) or scoped_guard(type_init, ...).
	2. Use context_unsafe() for simple initialization.

Reported-by: Bart Van Assche 
Signed-off-by: Marco Elver 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/all/57062131-e79e-42c2-aa0b-8f931cb8cac2@acm.org/
Link: https://patch.msgid.link/20260119094029.1344361-7-elver@google.com

compiler-context-analysis: Introduce scoped init guards

2026-01-28T19:45:24+00:00

Add scoped init guard definitions for common synchronization primitives
supported by context analysis.

The scoped init guards treat the context as active within initialization
scope of the underlying context lock, given initialization implies
exclusive access to the underlying object. This allows initialization of
guarded members without disabling context analysis, while documenting
initialization from subsequent usage.

The documentation is updated with the new recommendation. Where scoped
init guards are not provided or cannot be implemented (ww_mutex omitted
for lack of multi-arg guard initializers), the alternative is to just
disable context analysis where guarded members are initialized.

Suggested-by: Peter Zijlstra 
Signed-off-by: Marco Elver 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/all/20251212095943.GM3911114@noisy.programming.kicks-ass.net/
Link: https://patch.msgid.link/20260119094029.1344361-3-elver@google.com

locking/mutex: Support Clang's context analysis

2026-01-05T15:43:29+00:00

Add support for Clang's context analysis for mutex.

Signed-off-by: Marco Elver 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20251219154418.3592607-11-elver@google.com

locking/mutex: Redo __mutex_init() to reduce generated code size

2025-12-01T05:51:57+00:00

mutex_init() invokes __mutex_init() providing the name of the lock and
a pointer to a the lock class. With LOCKDEP enabled this information is
useful but without LOCKDEP it not used at all. Passing the pointer
information of the lock class might be considered negligible but the
name of the lock is passed as well and the string is stored. This
information is wasting storage.

Split __mutex_init() into a _genereic() variant doing the initialisation
of the lock and a _lockdep() version which does _genereic() plus the
lockdep bits. Restrict the lockdep version to lockdep enabled builds
allowing the compiler to remove the unused parameter.

This results in the following size reduction:

        text     data       bss        dec  filename
  | 30237599  8161430   1176624   39575653  vmlinux.defconfig
  | 30233269  8149142   1176560   39558971  vmlinux.defconfig.patched
     -4.2KiB   -12KiB

  | 32455099  8471098  12934684   53860881  vmlinux.defconfig.lockdep
  | 32455100  8471098  12934684   53860882  vmlinux.defconfig.patched.lockdep

  | 27152407  7191822   2068040   36412269  vmlinux.defconfig.preempt_rt
  | 27145937  7183630   2067976   36397543  vmlinux.defconfig.patched.preempt_rt
     -6.3KiB    -8KiB

  | 29382020  7505742  13784608   50672370  vmlinux.defconfig.preempt_rt.lockdep
  | 29376229  7505742  13784544   50666515  vmlinux.defconfig.patched.preempt_rt.lockdep
     -5.6KiB

[peterz: folded fix from boqun]

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Reviewed-by: Waiman Long 
Link: https://lkml.kernel.org/r/20251125145425.68319-1-boqun.feng@gmail.com
Link: https://patch.msgid.link/20251105142350.Tfeevs2N@linutronix.de

Merge tag 'cxl-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2025-08-01T22:47:06+00:00

Pull CXL updates from Dave Jiang:
 "The most significant changes in this pull request is the series that
  introduces ACQUIRE() and ACQUIRE_ERR() macros to replace conditional
  locking and ease the pain points of scoped_cond_guard().

  The series also includes follow on changes that refactor the CXL
  sub-system to utilize the new macros.

  Detail summary:

   - Add documentation template for CXL conventions to document CXL
     platform quirks

   - Replace mutex_lock_io() with mutex_lock() for mailbox

   - Add location limit for fake CFMWS range for cxl_test, ARM platform
     enabling

   - CXL documentation typo and clarity fixes

   - Use correct format specifier for function cxl_set_ecs_threshold()

   - Make cxl_bus_type constant

   - Introduce new helper cxl_resource_contains_addr() to check address
     availability

   - Fix wrong DPA checking for PPR operation

   - Remove core/acpi.c and CXL core dependency on ACPI

   - Introduce ACQUIRE() and ACQUIRE_ERR() for conditional locks

   - Add CXL updates utilizing ACQUIRE() macro to remove gotos and
     improve readability

   - Add return for the dummy version of cxl_decoder_detach() without
     CONFIG_CXL_REGION

   - CXL events updates for spec r3.2

   - Fix return of __cxl_decoder_detach() error path

   - CXL debugfs documentation fix"

* tag 'cxl-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (28 commits)
  Documentation/ABI/testing/debugfs-cxl: Add 'cxl' to clear_poison path
  cxl/region: Fix an ERR_PTR() vs NULL bug
  cxl/events: Trace Memory Sparing Event Record
  cxl/events: Add extra validity checks for CVME count in DRAM Event Record
  cxl/events: Add extra validity checks for corrected memory error count in General Media Event Record
  cxl/events: Update Common Event Record to CXL spec rev 3.2
  cxl: Fix -Werror=return-type in cxl_decoder_detach()
  cleanup: Fix documentation build error for ACQUIRE updates
  cxl: Convert to ACQUIRE() for conditional rwsem locking
  cxl/region: Consolidate cxl_decoder_kill_region() and cxl_region_detach()
  cxl/region: Move ready-to-probe state check to a helper
  cxl/region: Split commit_store() into __commit() and queue_reset() helpers
  cxl/decoder: Drop pointless locking
  cxl/decoder: Move decoder register programming to a helper
  cxl/mbox: Convert poison list mutex to ACQUIRE()
  cleanup: Introduce ACQUIRE() and ACQUIRE_ERR() for conditional locks
  cxl: Remove core/acpi.c and cxl core dependency on ACPI
  cxl/core: Using cxl_resource_contains_addr() to check address availability
  cxl/edac: Fix wrong dpa checking for PPR operation
  cxl/core: Introduce a new helper cxl_resource_contains_addr()
  ...