Merge branches 'doc.2020.06.29a', 'fixes.2020.06.29a',... (13625c0a) · Commits · 戴 / test

Documentation/admin-guide/kernel-parameters.txt

+68 −0

Original line number	Diff line number	Diff line
		@@ -4038,6 +4038,14 @@
		latencies, which will choose a value aligned
		with the appropriate hardware boundaries.

		rcutree.rcu_min_cached_objs= [KNL]
		Minimum number of objects which are cached and
		maintained per one CPU. Object size is equal
		to PAGE_SIZE. The cache allows to reduce the
		pressure to page allocator, also it makes the
		whole algorithm to behave better in low memory
		condition.

		rcutree.jiffies_till_first_fqs= [KNL]
		Set delay from grace-period initialization to
		first attempt to force quiescent states.
		@@ -4258,6 +4266,20 @@
		Set time (jiffies) between CPU-hotplug operations,
		or zero to disable CPU-hotplug testing.

		rcutorture.read_exit= [KNL]
		Set the number of read-then-exit kthreads used
		to test the interaction of RCU updaters and
		task-exit processing.

		rcutorture.read_exit_burst= [KNL]
		The number of times in a given read-then-exit
		episode that a set of read-then-exit kthreads
		is spawned.

		rcutorture.read_exit_delay= [KNL]
		The delay, in seconds, between successive
		read-then-exit testing episodes.

		rcutorture.shuffle_interval= [KNL]
		Set task-shuffle interval (s). Shuffling tasks
		allows some CPUs to go into dyntick-idle mode
		@@ -4407,6 +4429,45 @@
		reboot_cpu is s[mp]#### with #### being the processor
		to be used for rebooting.

		refscale.holdoff= [KNL]
		Set test-start holdoff period. The purpose of
		this parameter is to delay the start of the
		test until boot completes in order to avoid
		interference.

		refscale.loops= [KNL]
		Set the number of loops over the synchronization
		primitive under test. Increasing this number
		reduces noise due to loop start/end overhead,
		but the default has already reduced the per-pass
		noise to a handful of picoseconds on ca. 2020
		x86 laptops.

		refscale.nreaders= [KNL]
		Set number of readers. The default value of -1
		selects N, where N is roughly 75% of the number
		of CPUs. A value of zero is an interesting choice.

		refscale.nruns= [KNL]
		Set number of runs, each of which is dumped onto
		the console log.

		refscale.readdelay= [KNL]
		Set the read-side critical-section duration,
		measured in microseconds.

		refscale.scale_type= [KNL]
		Specify the read-protection implementation to test.

		refscale.shutdown= [KNL]
		Shut down the system at the end of the performance
		test. This defaults to 1 (shut it down) when
		rcuperf is built into the kernel and to 0 (leave
		it running) when rcuperf is built as a module.

		refscale.verbose= [KNL]
		Enable additional printk() statements.

		relax_domain_level=
		[KNL, SMP] Set scheduler's default relax_domain_level.
		See Documentation/admin-guide/cgroup-v1/cpusets.rst.
		@@ -5082,6 +5143,13 @@
		Prevent the CPU-hotplug component of torturing
		until after init has spawned.

		torture.ftrace_dump_at_shutdown= [KNL]
		Dump the ftrace buffer at torture-test shutdown,
		even if there were no errors. This can be a
		very costly operation when many torture tests
		are running concurrently, especially on systems
		with rotating-rust storage.

		tp720= [HW,PS2]

		tpm_suspend_pcr=[HW,TPM]

fs/btrfs/extent_io.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -4515,6 +4515,8 @@ int try_release_extent_mapping(struct page *page, gfp_t mask)

		/* once for us */
		free_extent_map(em);

		cond_resched(); /* Allow large-extent preemption. */
		}
		}
		return try_release_extent_state(tree, page, mask);

include/linux/rculist.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -512,7 +512,7 @@ static inline void hlist_replace_rcu(struct hlist_node *old,
		* @right: The hlist head on the right
		*
		* The lists start out as [@left ][node1 ... ] and
		[@right ][node2 ... ]
		* [@right ][node2 ... ]
		* The lists end up as [@left ][node2 ... ]
		* [@right ][node1 ... ]
		*/

include/linux/rcupdate.h

+46 −7

Original line number	Diff line number	Diff line
		@@ -828,17 +828,17 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)

		/*
		* Does the specified offset indicate that the corresponding rcu_head
		* structure can be handled by kfree_rcu()?
		* structure can be handled by kvfree_rcu()?
		*/
		#define __is_kfree_rcu_offset(offset) ((offset) < 4096)
		#define __is_kvfree_rcu_offset(offset) ((offset) < 4096)

		/*
		* Helper macro for kfree_rcu() to prevent argument-expansion eyestrain.
		*/
		#define __kfree_rcu(head, offset) \
		#define __kvfree_rcu(head, offset) \
		do { \
		BUILD_BUG_ON(!__is_kfree_rcu_offset(offset)); \
		kfree_call_rcu(head, (rcu_callback_t)(unsigned long)(offset)); \
		BUILD_BUG_ON(!__is_kvfree_rcu_offset(offset)); \
		kvfree_call_rcu(head, (rcu_callback_t)(unsigned long)(offset)); \
		} while (0)

		/**
		@@ -857,7 +857,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
		* Because the functions are not allowed in the low-order 4096 bytes of
		* kernel virtual memory, offsets up to 4095 bytes can be accommodated.
		* If the offset is larger than 4095 bytes, a compile-time error will
		* be generated in __kfree_rcu(). If this error is triggered, you can
		* be generated in __kvfree_rcu(). If this error is triggered, you can
		* either fall back to use of call_rcu() or rearrange the structure to
		* position the rcu_head structure into the first 4096 bytes.
		*
		@@ -872,7 +872,46 @@ do { \
		typeof (ptr) ___p = (ptr); \
		\
		if (___p) \
		__kfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
		__kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
		} while (0)

		/**
		* kvfree_rcu() - kvfree an object after a grace period.
		*
		* This macro consists of one or two arguments and it is
		* based on whether an object is head-less or not. If it
		* has a head then a semantic stays the same as it used
		* to be before:
		*
		* kvfree_rcu(ptr, rhf);
		*
		* where @ptr is a pointer to kvfree(), @rhf is the name
		* of the rcu_head structure within the type of @ptr.
		*
		* When it comes to head-less variant, only one argument
		* is passed and that is just a pointer which has to be
		* freed after a grace period. Therefore the semantic is
		*
		* kvfree_rcu(ptr);
		*
		* where @ptr is a pointer to kvfree().
		*
		* Please note, head-less way of freeing is permitted to
		* use from a context that has to follow might_sleep()
		* annotation. Otherwise, please switch and embed the
		* rcu_head structure within the type of @ptr.
		*/
		#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
		kvfree_rcu_arg_2, kvfree_rcu_arg_1)(__VA_ARGS__)

		#define KVFREE_GET_MACRO(_1, _2, NAME, ...) NAME
		#define kvfree_rcu_arg_2(ptr, rhf) kfree_rcu(ptr, rhf)
		#define kvfree_rcu_arg_1(ptr) \
		do { \
		typeof(ptr) ___p = (ptr); \
		\
		if (___p) \
		kvfree_call_rcu(NULL, (rcu_callback_t) (___p)); \
		} while (0)

		/*

include/linux/rcupdate_trace.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -36,8 +36,8 @@ void rcu_read_unlock_trace_special(struct task_struct *t, int nesting);
		/**
		* rcu_read_lock_trace - mark beginning of RCU-trace read-side critical section
		*
		* When synchronize_rcu_trace() is invoked by one task, then that task
		* is guaranteed to block until all other tasks exit their read-side
		* When synchronize_rcu_tasks_trace() is invoked by one task, then that
		* task is guaranteed to block until all other tasks exit their read-side
		* critical sections. Similarly, if call_rcu_trace() is invoked on one
		* task while other tasks are within RCU read-side critical sections,
		* invocation of the corresponding RCU callback is deferred until after

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