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author | Ingo Molnar <mingo@kernel.org> | 2020-07-31 01:15:53 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2020-07-31 01:15:53 +0300 |
commit | c1cc4784ce6e8cceff1013709abd74bcbf7fbf24 (patch) | |
tree | 5eaacf62240ec85a6ad9c7594e8ad8f7f783afc2 /include/linux | |
parent | 92ed301919932f777713b9172e525674157e983d (diff) | |
parent | 13625c0a4074d3bab61b1dc70a828b574255f339 (diff) | |
download | linux-c1cc4784ce6e8cceff1013709abd74bcbf7fbf24.tar.xz |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull the v5.9 RCU bits from Paul E. McKenney:
- Documentation updates
- Miscellaneous fixes
- kfree_rcu updates
- RCU tasks updates
- Read-side scalability tests
- SRCU updates
- Torture-test updates
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/rculist.h | 2 | ||||
-rw-r--r-- | include/linux/rculist_nulls.h | 2 | ||||
-rw-r--r-- | include/linux/rcupdate.h | 53 | ||||
-rw-r--r-- | include/linux/rcupdate_trace.h | 4 | ||||
-rw-r--r-- | include/linux/rcutiny.h | 20 | ||||
-rw-r--r-- | include/linux/rcutree.h | 2 | ||||
-rw-r--r-- | include/linux/torture.h | 5 |
7 files changed, 74 insertions, 14 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h index df587d181844..7eed65b5f713 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -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 ... ] */ diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h index 9670b54b484a..ff3e94779e73 100644 --- a/include/linux/rculist_nulls.h +++ b/include/linux/rculist_nulls.h @@ -162,7 +162,7 @@ static inline void hlist_nulls_add_fake(struct hlist_nulls_node *n) * The barrier() is needed to make sure compiler doesn't cache first element [1], * as this loop can be restarted [2] * [1] Documentation/core-api/atomic_ops.rst around line 114 - * [2] Documentation/RCU/rculist_nulls.txt around line 146 + * [2] Documentation/RCU/rculist_nulls.rst around line 146 */ #define hlist_nulls_for_each_entry_rcu(tpos, pos, head, member) \ for (({barrier();}), \ diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 659cbfa7581a..d15d46db61f7 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -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) /* diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h index 4c25a41f8b27..d9015aac78c6 100644 --- a/include/linux/rcupdate_trace.h +++ b/include/linux/rcupdate_trace.h @@ -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 diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 8512caeb7682..5cc9637cac16 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -34,9 +34,25 @@ static inline void synchronize_rcu_expedited(void) synchronize_rcu(); } -static inline void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) +/* + * Add one more declaration of kvfree() here. It is + * not so straight forward to just include <linux/mm.h> + * where it is defined due to getting many compile + * errors caused by that include. + */ +extern void kvfree(const void *addr); + +static inline void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) { - call_rcu(head, func); + if (head) { + call_rcu(head, func); + return; + } + + // kvfree_rcu(one_arg) call. + might_sleep(); + synchronize_rcu(); + kvfree((void *) func); } void rcu_qs(void); diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index d5cc9d675987..d2f4064ebd1d 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -33,7 +33,7 @@ static inline void rcu_virt_note_context_switch(int cpu) } void synchronize_rcu_expedited(void); -void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func); +void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func); void rcu_barrier(void); bool rcu_eqs_special_set(int cpu); diff --git a/include/linux/torture.h b/include/linux/torture.h index 629b66e6c161..7f65bd1dd307 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -55,6 +55,11 @@ struct torture_random_state { #define DEFINE_TORTURE_RANDOM_PERCPU(name) \ DEFINE_PER_CPU(struct torture_random_state, name) unsigned long torture_random(struct torture_random_state *trsp); +static inline void torture_random_init(struct torture_random_state *trsp) +{ + trsp->trs_state = 0; + trsp->trs_count = 0; +} /* Task shuffler, which causes CPUs to occasionally go idle. */ void torture_shuffle_task_register(struct task_struct *tp); |