Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 178 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-mic b/Documentation/ABI/testing/sysfs-class-mic
new file mode 100644
index 000000000..5e5f36d10
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-mic
@@ -0,0 +1,178 @@
+What:		/sys/class/mic/
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		The mic class directory belongs to Intel MIC devices and
+		provides information per MIC device. An Intel MIC device is a
+		PCIe form factor add-in Coprocessor card based on the Intel Many
+		Integrated Core (MIC) architecture that runs a Linux OS.
+
+What:		/sys/class/mic/mic<X>
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		The directories /sys/class/mic/mic0, /sys/class/mic/mic1 etc.,
+		represent MIC devices (0,1,..etc). Each directory has
+		information specific to that MIC device.
+
+What:		/sys/class/mic/mic<X>/family
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		Provides information about the Coprocessor family for an Intel
+		MIC device. For example - "x100"
+
+What:		/sys/class/mic/mic<X>/stepping
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		Provides information about the silicon stepping for an Intel
+		MIC device. For example - "A0" or "B0"
+
+What:		/sys/class/mic/mic<X>/state
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		When read, this entry provides the current state of an Intel
+		MIC device in the context of the card OS. Possible values that
+		will be read are:
+
+
+		===============  ===============================================
+		"ready"		 The MIC device is ready to boot the card OS.
+				 On reading this entry after an OSPM resume,
+				 a "boot" has to be written to this entry if
+				 the card was previously shutdown during OSPM
+				 suspend.
+		"booting"	 The MIC device has initiated booting a card OS.
+		"online"	 The MIC device has completed boot and is online
+		"shutting_down"	 The card OS is shutting down.
+		"resetting"	 A reset has been initiated for the MIC device
+		"reset_failed"	 The MIC device has failed to reset.
+		===============  ===============================================
+
+		When written, this sysfs entry triggers different state change
+		operations depending upon the current state of the card OS.
+		Acceptable values are:
+
+
+		==========  ===================================================
+		"boot"      Boot the card OS image specified by the combination
+			    of firmware, ramdisk, cmdline and bootmode
+			    sysfs entries.
+		"reset"     Initiates device reset.
+		"shutdown"  Initiates card OS shutdown.
+		==========  ===================================================
+
+What:		/sys/class/mic/mic<X>/shutdown_status
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		An Intel MIC device runs a Linux OS during its operation. This
+		OS can shutdown because of various reasons. When read, this
+		entry provides the status on why the card OS was shutdown.
+		Possible values are:
+
+		==========  ===================================================
+		"nop"       shutdown status is not applicable, when the card OS
+			    is "online"
+		"crashed"   Shutdown because of a HW or SW crash.
+		"halted"    Shutdown because of a halt command.
+		"poweroff"  Shutdown because of a poweroff command.
+		"restart"   Shutdown because of a restart command.
+		==========  ===================================================
+
+What:		/sys/class/mic/mic<X>/cmdline
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		An Intel MIC device runs a Linux OS during its operation. Before
+		booting this card OS, it is possible to pass kernel command line
+		options to configure various features in it, similar to
+		self-bootable machines. When read, this entry provides
+		information about the current kernel command line options set to
+		boot the card OS. This entry can be written to change the
+		existing kernel command line options. Typically, the user would
+		want to read the current command line options, append new ones
+		or modify existing ones and then write the whole kernel command
+		line back to this entry.
+
+What:		/sys/class/mic/mic<X>/firmware
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		When read, this sysfs entry provides the path name under
+		/lib/firmware/ where the firmware image to be booted on the
+		card can be found. The entry can be written to change the
+		firmware image location under /lib/firmware/.
+
+What:		/sys/class/mic/mic<X>/ramdisk
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		When read, this sysfs entry provides the path name under
+		/lib/firmware/ where the ramdisk image to be used during card
+		OS boot can be found. The entry can be written to change
+		the ramdisk image location under /lib/firmware/.
+
+What:		/sys/class/mic/mic<X>/bootmode
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		When read, this sysfs entry provides the current bootmode for
+		the card. This sysfs entry can be written with the following
+		valid strings:
+		a) linux - Boot a Linux image.
+		b) flash - Boot an image for flash updates.
+
+What:		/sys/class/mic/mic<X>/log_buf_addr
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		An Intel MIC device runs a Linux OS during its operation. For
+		debugging purpose and early kernel boot messages, the user can
+		access the card OS log buffer via debugfs. When read, this entry
+		provides the kernel virtual address of the buffer where the card
+		OS log buffer can be read. This entry is written by the host
+		configuration daemon to set the log buffer address. The correct
+		log buffer address to be written can be found in the System.map
+		file of the card OS.
+
+What:		/sys/class/mic/mic<X>/log_buf_len
+Date:		October 2013
+KernelVersion:	3.13
+Contact:	Sudeep Dutt <sudeep.dutt@intel.com>
+Description:
+		An Intel MIC device runs a Linux OS during its operation. For
+		debugging purpose and early kernel boot messages, the user can
+		access the card OS log buffer via debugfs. When read, this entry
+		provides the kernel virtual address where the card OS log buffer
+		length can be read. This entry is written by host configuration
+		daemon to set the log buffer length address. The correct log
+		buffer length address to be written can be found in the
+		System.map file of the card OS.
+
+What:		/sys/class/mic/mic<X>/heartbeat_enable
+Date:		March 2015
+KernelVersion:	4.4
+Contact:	Ashutosh Dixit <ashutosh.dixit@intel.com>
+Description:
+		The MIC drivers detect and inform user space about card crashes
+		via a heartbeat mechanism (see the description of
+		shutdown_status above). User space can turn off this
+		notification by setting heartbeat_enable to 0 and enable it by
+		setting this entry to 1. If this notification is disabled it is
+		the responsibility of user space to detect card crashes via
+		alternative means such as a network ping. This setting is
+		enabled by default.