Greg, Rafael,
Here are some extensions to the 'lockdep_mutex' I came up with after
getting tired of alternating debug builds between CXL and NVDIMM
subsystem testing, and worrying about the missing lockdep coverage from
device-lock acquisition in the device-core.
The primary insight is that the existing users of the 'lockdep_mutex'
are just wrapping calls to device_lock() with a subsystem local helper
that can apply the proper lock_class for how those subsystems nest the
device_lock(). Instead of local wrapping just instruct the subsystem to
annotate the lock_class directly in the device and let the device_lock()
common code handle acquiring lockdep_mutex with the proper class.
The final patch in the series extends this further and adds an array of
lockdep_mutex instances, 1 per subsystem, so that multiple subsystems can
be validated in a single kernel image.
This has been useful for identifying scenarios when it is safe to
acquire the device_lock() in a sysfs attribute.
Thoughts?
I know its late in the cycle to be messing with device-core internals,
so feel free to put this off until 5.19. This series is based on the
cxl_device_lock() enabling that is currently in -next.
---
Dan Williams (11):
device-core: Enable lockdep validation
cxl/core: Refactor a cxl_lock_class() out of cxl_nested_lock()
cxl/core: Remove cxl_device_lock()
cxl/core: Clamp max lock_class
cxl/core: Introduce cxl_set_lock_class()
cxl/acpi: Add a lock class for the root platform device
libnvdimm: Refactor an nvdimm_lock_class() helper
ACPI: NFIT: Drop nfit_device_lock()
libnvdimm: Drop nd_device_lock()
libnvdimm: Enable lockdep validation
device-core: Introduce a per-subsystem lockdep_mutex
drivers/acpi/nfit/core.c | 30 +++++----
drivers/acpi/nfit/nfit.h | 24 -------
drivers/base/core.c | 5 --
drivers/cxl/acpi.c | 1
drivers/cxl/core/memdev.c | 1
drivers/cxl/core/pmem.c | 6 +-
drivers/cxl/core/port.c | 52 ++++++++--------
drivers/cxl/core/region.c | 1
drivers/cxl/cxl.h | 72 ++++++++--------------
drivers/cxl/mem.c | 4 +
drivers/cxl/pmem.c | 12 ++--
drivers/cxl/port.c | 2 -
drivers/nvdimm/btt_devs.c | 16 ++---
drivers/nvdimm/bus.c | 26 ++++----
drivers/nvdimm/core.c | 10 ++-
drivers/nvdimm/dimm_devs.c | 8 +-
drivers/nvdimm/namespace_devs.c | 36 +++++------
drivers/nvdimm/nd-core.h | 51 ++++-----------
drivers/nvdimm/pfn_devs.c | 24 ++++---
drivers/nvdimm/pmem.c | 2 -
drivers/nvdimm/region.c | 2 -
drivers/nvdimm/region_devs.c | 16 ++---
include/linux/device.h | 130 ++++++++++++++++++++++++++++++++++++++-
lib/Kconfig.debug | 23 -------
24 files changed, 291 insertions(+), 263 deletions(-)
base-commit: 74be98774dfbc5b8b795db726bd772e735d2edd4
