diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html index e4d94fba6c89..8d21af02b1f0 100644 --- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html +++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.html @@ -485,13 +485,13 @@ section that the grace period must wait on. noted by rcu_node_context_switch() on the left. On the other hand, if the CPU takes a scheduler-clock interrupt while executing in usermode, a quiescent state will be noted by -rcu_check_callbacks() on the right. +rcu_sched_clock_irq() on the right. Either way, the passage through a quiescent state will be noted in a per-CPU variable.

The next time an RCU_SOFTIRQ handler executes on this CPU (for example, after the next scheduler-clock -interrupt), __rcu_process_callbacks() will invoke +interrupt), rcu_core() will invoke rcu_check_quiescent_state(), which will notice the recorded quiescent state, and invoke rcu_report_qs_rdp(). @@ -651,7 +651,7 @@ to end. These callbacks are identified by rcu_advance_cbs(), which is usually invoked by __note_gp_changes(). As shown in the diagram below, this invocation can be triggered by -the scheduling-clock interrupt (rcu_check_callbacks() on +the scheduling-clock interrupt (rcu_sched_clock_irq() on the left) or by idle entry (rcu_cleanup_after_idle() on the right, but only for kernels build with CONFIG_RCU_FAST_NO_HZ=y). diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg index 832408313d93..3fcf0c17cef2 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-invocation.svg @@ -349,7 +349,7 @@ font-weight="bold" font-size="192" id="text202-7-5" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_check_callbacks() + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq() rcu_check_callbacks() + xml:space="preserve">rcu_sched_clock_irq() rcu_process_callbacks() + xml:space="preserve">rcu_core() rcu_check_quiescent_state()) + xml:space="preserve">rcu_check_quiescent_state() rcu_check_callbacks() + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_sched_clock_irq() rcu_check_callbacks() + xml:space="preserve">rcu_sched_clock_irq() rcu_process_callbacks() + xml:space="preserve">rcu_core() rcu_check_quiescent_state()) + xml:space="preserve">rcu_check_quiescent_state() +S: Maintained +T: git git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/nolibc.git +F: tools/include/nolibc/ + NTB AMD DRIVER M: Shyam Sundar S K L: linux-ntb@googlegroups.com diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 20561a60db9c..0e9bd9c83870 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -211,9 +211,6 @@ void __warn(const char *file, int line, void *caller, unsigned taint, /* * WARN_ON_SMP() is for cases that the warning is either * meaningless for !SMP or may even cause failures. - * This is usually used for cases that we have - * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked() - * returns 0 for uniprocessor settings. * It can also be used with values that are only defined * on SMP: * diff --git a/include/linux/rcu_node_tree.h b/include/linux/rcu_node_tree.h index 426cee67f0e2..b8e094b125ee 100644 --- a/include/linux/rcu_node_tree.h +++ b/include/linux/rcu_node_tree.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU node combining tree definitions. These are used to compute * global attributes while avoiding common-case global contention. A key @@ -11,23 +12,9 @@ * because the size of the TREE SRCU srcu_struct structure depends * on these definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney */ #ifndef __LINUX_RCU_NODE_TREE_H diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index c3ad00e63556..87404cb015f1 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU segmented callback lists * @@ -5,23 +6,9 @@ * because the size of the TREE SRCU srcu_struct structure depends * on these definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney */ #ifndef __INCLUDE_LINUX_RCU_SEGCBLIST_H diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h index ece7ed9a4a70..6fc53a1345b3 100644 --- a/include/linux/rcu_sync.h +++ b/include/linux/rcu_sync.h @@ -1,20 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU-based infrastructure for lightweight reader-writer locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (c) 2015, Red Hat, Inc. * * Author: Oleg Nesterov diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 0e39e0d2629e..6cdb1db776cf 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -1,25 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2001 * * Author: Dipankar Sarma * - * Based on the original work by Paul McKenney + * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf @@ -89,7 +76,7 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); extern int rcu_scheduler_active __read_mostly; -void rcu_check_callbacks(int user); +void rcu_sched_clock_irq(int user); void rcu_report_dead(unsigned int cpu); void rcutree_migrate_callbacks(int cpu); @@ -309,16 +296,16 @@ static inline void rcu_preempt_sleep_check(void) { } */ #ifdef __CHECKER__ -#define rcu_dereference_sparse(p, space) \ +#define rcu_check_sparse(p, space) \ ((void)(((typeof(*p) space *)p) == p)) #else /* #ifdef __CHECKER__ */ -#define rcu_dereference_sparse(p, space) +#define rcu_check_sparse(p, space) #endif /* #else #ifdef __CHECKER__ */ #define __rcu_access_pointer(p, space) \ ({ \ typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(_________p1)); \ }) #define __rcu_dereference_check(p, c, space) \ @@ -326,13 +313,13 @@ static inline void rcu_preempt_sleep_check(void) { } /* Dependency order vs. p above. */ \ typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(________p1)); \ }) #define __rcu_dereference_protected(p, c, space) \ ({ \ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ - rcu_dereference_sparse(p, space); \ + rcu_check_sparse(p, space); \ ((typeof(*p) __force __kernel *)(p)); \ }) #define rcu_dereference_raw(p) \ @@ -382,6 +369,7 @@ static inline void rcu_preempt_sleep_check(void) { } #define rcu_assign_pointer(p, v) \ ({ \ uintptr_t _r_a_p__v = (uintptr_t)(v); \ + rcu_check_sparse(p, __rcu); \ \ if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \ WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \ @@ -785,7 +773,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) */ #define RCU_INIT_POINTER(p, v) \ do { \ - rcu_dereference_sparse(p, __rcu); \ + rcu_check_sparse(p, __rcu); \ WRITE_ONCE(p, RCU_INITIALIZER(v)); \ } while (0) @@ -859,7 +847,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /* Has the specified rcu_head structure been handed to call_rcu()? */ -/* +/** * rcu_head_init - Initialize rcu_head for rcu_head_after_call_rcu() * @rhp: The rcu_head structure to initialize. * @@ -874,10 +862,10 @@ static inline void rcu_head_init(struct rcu_head *rhp) rhp->func = (rcu_callback_t)~0L; } -/* +/** * rcu_head_after_call_rcu - Has this rcu_head been passed to call_rcu()? * @rhp: The rcu_head structure to test. - * @func: The function passed to call_rcu() along with @rhp. + * @f: The function passed to call_rcu() along with @rhp. * * Returns @true if the @rhp has been passed to call_rcu() with @func, * and @false otherwise. Emits a warning in any other case, including diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index af65d1f36ddb..8e727f57d814 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 7f83179177d1..735601ac27d3 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -1,26 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Author: Dipankar Sarma - * Paul E. McKenney Hierarchical algorithm + * Paul E. McKenney Hierarchical algorithm * - * Based on the original work by Paul McKenney + * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - diff --git a/include/linux/srcu.h b/include/linux/srcu.h index c614375cd264..c495b2d51569 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2006 * Copyright (C) Fujitsu, 2012 * - * Author: Paul McKenney + * Author: Paul McKenney * Lai Jiangshan * * For detailed explanation of Read-Copy Update mechanism see - @@ -223,6 +210,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp) static inline void srcu_read_unlock(struct srcu_struct *ssp, int idx) __releases(ssp) { + WARN_ON_ONCE(idx & ~0x1); rcu_lock_release(&(ssp)->dep_map); __srcu_read_unlock(ssp, idx); } diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index b19216aaaef2..5a5a1941ca15 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tiny variant. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney + * Author: Paul McKenney */ #ifndef _LINUX_SRCU_TINY_H diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 6f292bd3e7db..7f7c8c050f63 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -1,24 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tree variant. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney + * Author: Paul McKenney */ #ifndef _LINUX_SRCU_TREE_H @@ -45,7 +32,8 @@ struct srcu_data { unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ bool srcu_cblist_invoking; /* Invoking these CBs? */ - struct delayed_work work; /* Context for CB invoking. */ + struct timer_list delay_work; /* Delay for CB invoking */ + struct work_struct work; /* Context for CB invoking. */ struct rcu_head srcu_barrier_head; /* For srcu_barrier() use. */ struct srcu_node *mynode; /* Leaf srcu_node. */ unsigned long grpmask; /* Mask for leaf srcu_node */ diff --git a/include/linux/torture.h b/include/linux/torture.h index 48fad21109fc..23d80db426d7 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Common functions for in-kernel torture tests. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2014 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney */ #ifndef __LINUX_TORTURE_H @@ -50,11 +37,12 @@ do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0) /* Definitions for online/offline exerciser. */ +typedef void torture_ofl_func(void); bool torture_offline(int cpu, long *n_onl_attempts, long *n_onl_successes, unsigned long *sum_offl, int *min_onl, int *max_onl); bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, unsigned long *sum_onl, int *min_onl, int *max_onl); -int torture_onoff_init(long ooholdoff, long oointerval); +int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f); void torture_onoff_stats(void); bool torture_onoff_failures(void); diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 7d0b0ed74404..ad40a2617063 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Module-based torture test facility for locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2014 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney * Davidlohr Bueso * Based on kernel/rcu/torture.c. */ @@ -45,7 +32,7 @@ #include MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney "); +MODULE_AUTHOR("Paul E. McKenney "); torture_param(int, nwriters_stress, -1, "Number of write-locking stress-test threads"); @@ -970,7 +957,7 @@ static int __init lock_torture_init(void) /* Prepare torture context. */ if (onoff_interval > 0) { firsterr = torture_onoff_init(onoff_holdoff * HZ, - onoff_interval * HZ); + onoff_interval * HZ, NULL); if (firsterr) goto unwind; } diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 75787186bd4f..acee72c0b24b 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update definitions shared among RCU implementations. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2011 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney */ #ifndef __LINUX_RCU_H @@ -30,7 +17,7 @@ #define RCU_TRACE(stmt) #endif /* #else #ifdef CONFIG_RCU_TRACE */ -/* Offset to allow for unmatched rcu_irq_{enter,exit}(). */ +/* Offset to allow distinguishing irq vs. task-based idle entry/exit. */ #define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1) diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c index 5aff271adf1e..9bd5f6023c21 100644 --- a/kernel/rcu/rcu_segcblist.c +++ b/kernel/rcu/rcu_segcblist.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * RCU segmented callback lists, function definitions * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney */ #include diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h index 948470cef385..71b64648464e 100644 --- a/kernel/rcu/rcu_segcblist.h +++ b/kernel/rcu/rcu_segcblist.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU segmented callback lists, internal-to-rcu header file * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2017 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney */ #include diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index b459da70b4fc..c29761152874 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update module-based performance-test facility * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2015 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney */ #define pr_fmt(fmt) fmt @@ -54,7 +41,7 @@ #include "rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney "); +MODULE_AUTHOR("Paul E. McKenney "); #define PERF_FLAG "-perf:" #define PERFOUT_STRING(s) \ @@ -83,13 +70,19 @@ MODULE_AUTHOR("Paul E. McKenney "); * Various other use cases may of course be specified. */ +#ifdef MODULE +# define RCUPERF_SHUTDOWN 0 +#else +# define RCUPERF_SHUTDOWN 1 +#endif + torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives"); torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader"); torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); torture_param(int, holdoff, 10, "Holdoff time before test start (s)"); torture_param(int, nreaders, -1, "Number of RCU reader threads"); torture_param(int, nwriters, -1, "Number of RCU updater threads"); -torture_param(bool, shutdown, !IS_ENABLED(MODULE), +torture_param(bool, shutdown, RCUPERF_SHUTDOWN, "Shutdown at end of performance tests."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable"); diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index f6e85faa4ff4..f14d1b18a74f 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update module-based torture test facility * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2005, 2006 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney * Josh Triplett * * See also: Documentation/RCU/torture.txt @@ -61,7 +48,7 @@ #include "rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney and Josh Triplett "); +MODULE_AUTHOR("Paul E. McKenney and Josh Triplett "); /* Bits for ->extendables field, extendables param, and related definitions. */ @@ -1630,21 +1617,34 @@ static bool rcu_fwd_emergency_stop; #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ -static long n_launders_hist[2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)]; +struct rcu_launder_hist { + long n_launders; + unsigned long launder_gp_seq; +}; +#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) +static struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; +static unsigned long rcu_launder_gp_seq_start; static void rcu_torture_fwd_cb_hist(void) { + unsigned long gps; + unsigned long gps_old; int i; int j; for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--) - if (n_launders_hist[i] > 0) + if (n_launders_hist[i].n_launders > 0) break; pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):", __func__, jiffies - rcu_fwd_startat); - for (j = 0; j <= i; j++) - pr_cont(" %ds/%d: %ld", - j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j]); + gps_old = rcu_launder_gp_seq_start; + for (j = 0; j <= i; j++) { + gps = n_launders_hist[j].launder_gp_seq; + pr_cont(" %ds/%d: %ld:%ld", + j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j].n_launders, + rcutorture_seq_diff(gps, gps_old)); + gps_old = gps; + } pr_cont("\n"); } @@ -1666,7 +1666,8 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) i = ((jiffies - rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); if (i >= ARRAY_SIZE(n_launders_hist)) i = ARRAY_SIZE(n_launders_hist) - 1; - n_launders_hist[i]++; + n_launders_hist[i].n_launders++; + n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); spin_unlock_irqrestore(&rcu_fwd_lock, flags); } @@ -1786,9 +1787,10 @@ static void rcu_torture_fwd_prog_cr(void) n_max_cbs = 0; n_max_gps = 0; for (i = 0; i < ARRAY_SIZE(n_launders_hist); i++) - n_launders_hist[i] = 0; + n_launders_hist[i].n_launders = 0; cver = READ_ONCE(rcu_torture_current_version); gps = cur_ops->get_gp_seq(); + rcu_launder_gp_seq_start = gps; while (time_before(jiffies, stopat) && !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { rfcp = READ_ONCE(rcu_fwd_cb_head); @@ -2228,6 +2230,14 @@ static void rcu_test_debug_objects(void) #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ } +static void rcutorture_sync(void) +{ + static unsigned long n; + + if (cur_ops->sync && !(++n & 0xfff)) + cur_ops->sync(); +} + static int __init rcu_torture_init(void) { @@ -2389,7 +2399,8 @@ rcu_torture_init(void) firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); if (firsterr) goto unwind; - firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval); + firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, + rcutorture_sync); if (firsterr) goto unwind; firsterr = rcu_torture_stall_init(); diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 32dfd6522548..5d4a39a6505a 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -1,24 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Sleepable Read-Copy Update mechanism for mutual exclusion, * tiny version for non-preemptible single-CPU use. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2017 * - * Author: Paul McKenney + * Author: Paul McKenney */ #include diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 3600d88d8956..a60b8ba9e1ac 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1,24 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Sleepable Read-Copy Update mechanism for mutual exclusion. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2006 * Copyright (C) Fujitsu, 2012 * - * Author: Paul McKenney + * Author: Paul McKenney * Lai Jiangshan * * For detailed explanation of Read-Copy Update mechanism see - @@ -58,6 +45,7 @@ static bool __read_mostly srcu_init_done; static void srcu_invoke_callbacks(struct work_struct *work); static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay); static void process_srcu(struct work_struct *work); +static void srcu_delay_timer(struct timer_list *t); /* Wrappers for lock acquisition and release, see raw_spin_lock_rcu_node(). */ #define spin_lock_rcu_node(p) \ @@ -156,7 +144,8 @@ static void init_srcu_struct_nodes(struct srcu_struct *ssp, bool is_static) snp->grphi = cpu; } sdp->cpu = cpu; - INIT_DELAYED_WORK(&sdp->work, srcu_invoke_callbacks); + INIT_WORK(&sdp->work, srcu_invoke_callbacks); + timer_setup(&sdp->delay_work, srcu_delay_timer, 0); sdp->ssp = ssp; sdp->grpmask = 1 << (cpu - sdp->mynode->grplo); if (is_static) @@ -386,13 +375,19 @@ void _cleanup_srcu_struct(struct srcu_struct *ssp, bool quiesced) } else { flush_delayed_work(&ssp->work); } - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { + struct srcu_data *sdp = per_cpu_ptr(ssp->sda, cpu); + if (quiesced) { - if (WARN_ON(delayed_work_pending(&per_cpu_ptr(ssp->sda, cpu)->work))) + if (WARN_ON(timer_pending(&sdp->delay_work))) + return; /* Just leak it! */ + if (WARN_ON(work_pending(&sdp->work))) return; /* Just leak it! */ } else { - flush_delayed_work(&per_cpu_ptr(ssp->sda, cpu)->work); + del_timer_sync(&sdp->delay_work); + flush_work(&sdp->work); } + } if (WARN_ON(rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) != SRCU_STATE_IDLE) || WARN_ON(srcu_readers_active(ssp))) { pr_info("%s: Active srcu_struct %p state: %d\n", @@ -463,39 +458,23 @@ static void srcu_gp_start(struct srcu_struct *ssp) WARN_ON_ONCE(state != SRCU_STATE_SCAN1); } -/* - * Track online CPUs to guide callback workqueue placement. - */ -DEFINE_PER_CPU(bool, srcu_online); -void srcu_online_cpu(unsigned int cpu) +static void srcu_delay_timer(struct timer_list *t) { - WRITE_ONCE(per_cpu(srcu_online, cpu), true); + struct srcu_data *sdp = container_of(t, struct srcu_data, delay_work); + + queue_work_on(sdp->cpu, rcu_gp_wq, &sdp->work); } -void srcu_offline_cpu(unsigned int cpu) -{ - WRITE_ONCE(per_cpu(srcu_online, cpu), false); -} - -/* - * Place the workqueue handler on the specified CPU if online, otherwise - * just run it whereever. This is useful for placing workqueue handlers - * that are to invoke the specified CPU's callbacks. - */ -static bool srcu_queue_delayed_work_on(int cpu, struct workqueue_struct *wq, - struct delayed_work *dwork, +static void srcu_queue_delayed_work_on(struct srcu_data *sdp, unsigned long delay) { - bool ret; + if (!delay) { + queue_work_on(sdp->cpu, rcu_gp_wq, &sdp->work); + return; + } - preempt_disable(); - if (READ_ONCE(per_cpu(srcu_online, cpu))) - ret = queue_delayed_work_on(cpu, wq, dwork, delay); - else - ret = queue_delayed_work(wq, dwork, delay); - preempt_enable(); - return ret; + timer_reduce(&sdp->delay_work, jiffies + delay); } /* @@ -504,7 +483,7 @@ static bool srcu_queue_delayed_work_on(int cpu, struct workqueue_struct *wq, */ static void srcu_schedule_cbs_sdp(struct srcu_data *sdp, unsigned long delay) { - srcu_queue_delayed_work_on(sdp->cpu, rcu_gp_wq, &sdp->work, delay); + srcu_queue_delayed_work_on(sdp, delay); } /* @@ -1186,7 +1165,8 @@ static void srcu_invoke_callbacks(struct work_struct *work) struct srcu_data *sdp; struct srcu_struct *ssp; - sdp = container_of(work, struct srcu_data, work.work); + sdp = container_of(work, struct srcu_data, work); + ssp = sdp->ssp; rcu_cblist_init(&ready_cbs); spin_lock_irq_rcu_node(sdp); diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index be10036fa621..a8304d90573f 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -1,20 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * RCU-based infrastructure for lightweight reader-writer locking * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (c) 2015, Red Hat, Inc. * * Author: Oleg Nesterov diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c index 5f5963ba313e..911bd9076d43 100644 --- a/kernel/rcu/tiny.c +++ b/kernel/rcu/tiny.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU @@ -76,7 +63,7 @@ void rcu_qs(void) * be called from hardirq context. It is normally called from the * scheduling-clock interrupt. */ -void rcu_check_callbacks(int user) +void rcu_sched_clock_irq(int user) { if (user) { rcu_qs(); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 1c4add096078..3b084dbfb4bc 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1,27 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Authors: Dipankar Sarma * Manfred Spraul - * Paul E. McKenney Hierarchical version + * Paul E. McKenney Hierarchical version * - * Based on the original work by Paul McKenney + * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - @@ -725,7 +712,6 @@ static __always_inline void rcu_nmi_exit_common(bool irq) /** * rcu_nmi_exit - inform RCU of exit from NMI context - * @irq: Is this call from rcu_irq_exit? * * If you add or remove a call to rcu_nmi_exit(), be sure to test * with CONFIG_RCU_EQS_DEBUG=y. @@ -1139,7 +1125,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) } /* - * NO_HZ_FULL CPUs can run in-kernel without rcu_check_callbacks! + * NO_HZ_FULL CPUs can run in-kernel without rcu_sched_clock_irq! * The above code handles this, but only for straight cond_resched(). * And some in-kernel loops check need_resched() before calling * cond_resched(), which defeats the above code for CPUs that are @@ -2532,14 +2518,14 @@ static void rcu_do_batch(struct rcu_data *rdp) } /* - * Check to see if this CPU is in a non-context-switch quiescent state - * (user mode or idle loop for rcu, non-softirq execution for rcu_bh). - * Also schedule RCU core processing. - * - * This function must be called from hardirq context. It is normally - * invoked from the scheduling-clock interrupt. + * This function is invoked from each scheduling-clock interrupt, + * and checks to see if this CPU is in a non-context-switch quiescent + * state, for example, user mode or idle loop. It also schedules RCU + * core processing. If the current grace period has gone on too long, + * it will ask the scheduler to manufacture a context switch for the sole + * purpose of providing a providing the needed quiescent state. */ -void rcu_check_callbacks(int user) +void rcu_sched_clock_irq(int user) { trace_rcu_utilization(TPS("Start scheduler-tick")); raw_cpu_inc(rcu_data.ticks_this_gp); @@ -2552,7 +2538,7 @@ void rcu_check_callbacks(int user) } __this_cpu_write(rcu_data.rcu_urgent_qs, false); } - rcu_flavor_check_callbacks(user); + rcu_flavor_sched_clock_irq(user); if (rcu_pending()) invoke_rcu_core(); @@ -2742,12 +2728,8 @@ void rcu_fwd_progress_check(unsigned long j) } EXPORT_SYMBOL_GPL(rcu_fwd_progress_check); -/* - * This does the RCU core processing work for the specified rcu_data - * structures. This may be called only from the CPU to whom the rdp - * belongs. - */ -static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) +/* Perform RCU core processing work for the current CPU. */ +static __latent_entropy void rcu_core(struct softirq_action *unused) { unsigned long flags; struct rcu_data *rdp = raw_cpu_ptr(&rcu_data); @@ -3408,8 +3390,6 @@ int rcutree_online_cpu(unsigned int cpu) raw_spin_lock_irqsave_rcu_node(rnp, flags); rnp->ffmask |= rdp->grpmask; raw_spin_unlock_irqrestore_rcu_node(rnp, flags); - if (IS_ENABLED(CONFIG_TREE_SRCU)) - srcu_online_cpu(cpu); if (rcu_scheduler_active == RCU_SCHEDULER_INACTIVE) return 0; /* Too early in boot for scheduler work. */ sync_sched_exp_online_cleanup(cpu); @@ -3434,8 +3414,6 @@ int rcutree_offline_cpu(unsigned int cpu) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); rcutree_affinity_setting(cpu, cpu); - if (IS_ENABLED(CONFIG_TREE_SRCU)) - srcu_offline_cpu(cpu); return 0; } @@ -3856,7 +3834,7 @@ void __init rcu_init(void) rcu_init_one(); if (dump_tree) rcu_dump_rcu_node_tree(); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); + open_softirq(RCU_SOFTIRQ, rcu_core); /* * We don't need protection against CPU-hotplug here because diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 149557b7c39c..bb4f995f2d3f 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -1,25 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * Internal non-public definitions. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2008 * * Author: Ingo Molnar - * Paul E. McKenney + * Paul E. McKenney */ #include @@ -417,7 +404,7 @@ static void rcu_print_detail_task_stall(void); static int rcu_print_task_stall(struct rcu_node *rnp); static int rcu_print_task_exp_stall(struct rcu_node *rnp); static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); -static void rcu_flavor_check_callbacks(int user); +static void rcu_flavor_sched_clock_irq(int user); void call_rcu(struct rcu_head *head, rcu_callback_t func); static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); @@ -458,11 +445,3 @@ static void rcu_bind_gp_kthread(void); static bool rcu_nohz_full_cpu(void); static void rcu_dynticks_task_enter(void); static void rcu_dynticks_task_exit(void); - -#ifdef CONFIG_SRCU -void srcu_online_cpu(unsigned int cpu); -void srcu_offline_cpu(unsigned int cpu); -#else /* #ifdef CONFIG_SRCU */ -void srcu_online_cpu(unsigned int cpu) { } -void srcu_offline_cpu(unsigned int cpu) { } -#endif /* #else #ifdef CONFIG_SRCU */ diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index d882ca0cd01b..4c2a0189e748 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -1,23 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * RCU expedited grace periods * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2016 * - * Authors: Paul E. McKenney + * Authors: Paul E. McKenney */ #include @@ -448,7 +435,6 @@ static void sync_rcu_exp_select_cpus(void) continue; } INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus); - preempt_disable(); cpu = find_next_bit(&rnp->ffmask, BITS_PER_LONG, -1); /* If all offline, queue the work on an unbound CPU. */ if (unlikely(cpu > rnp->grphi - rnp->grplo)) @@ -456,7 +442,6 @@ static void sync_rcu_exp_select_cpus(void) else cpu += rnp->grplo; queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work); - preempt_enable(); rnp->exp_need_flush = true; } diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 8ceed9e25ad5..97dba50f6fb2 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1,27 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * Internal non-public definitions that provide either classic * or preemptible semantics. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright Red Hat, 2009 * Copyright IBM Corporation, 2009 * * Author: Ingo Molnar - * Paul E. McKenney + * Paul E. McKenney */ #include @@ -297,7 +284,7 @@ static void rcu_qs(void) __this_cpu_read(rcu_data.gp_seq), TPS("cpuqs")); __this_cpu_write(rcu_data.cpu_no_qs.b.norm, false); - barrier(); /* Coordinate with rcu_flavor_check_callbacks(). */ + barrier(); /* Coordinate with rcu_flavor_sched_clock_irq(). */ current->rcu_read_unlock_special.b.need_qs = false; } } @@ -778,13 +765,13 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) } /* - * Check for a quiescent state from the current CPU. When a task blocks, - * the task is recorded in the corresponding CPU's rcu_node structure, - * which is checked elsewhere. - * - * Caller must disable hard irqs. + * Check for a quiescent state from the current CPU, including voluntary + * context switches for Tasks RCU. When a task blocks, the task is + * recorded in the corresponding CPU's rcu_node structure, which is checked + * elsewhere, hence this function need only check for quiescent states + * related to the current CPU, not to those related to tasks. */ -static void rcu_flavor_check_callbacks(int user) +static void rcu_flavor_sched_clock_irq(int user) { struct task_struct *t = current; @@ -1030,14 +1017,10 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) } /* - * Check to see if this CPU is in a non-context-switch quiescent state - * (user mode or idle loop for rcu, non-softirq execution for rcu_bh). - * Also schedule RCU core processing. - * - * This function must be called from hardirq context. It is normally - * invoked from the scheduling-clock interrupt. + * Check to see if this CPU is in a non-context-switch quiescent state, + * namely user mode and idle loop. */ -static void rcu_flavor_check_callbacks(int user) +static void rcu_flavor_sched_clock_irq(int user) { if (user || rcu_is_cpu_rrupt_from_idle()) { diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 1971869c4072..e3c6395c9b4c 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -1,26 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Read-Copy Update mechanism for mutual exclusion * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright IBM Corporation, 2001 * * Authors: Dipankar Sarma * Manfred Spraul * - * Based on the original work by Paul McKenney + * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 444156debfa0..6eb7cc4b6d52 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1632,7 +1632,7 @@ void update_process_times(int user_tick) /* Note: this timer irq context must be accounted for as well. */ account_process_tick(p, user_tick); run_local_timers(); - rcu_check_callbacks(user_tick); + rcu_sched_clock_irq(user_tick); #ifdef CONFIG_IRQ_WORK if (in_irq()) irq_work_tick(); diff --git a/kernel/torture.c b/kernel/torture.c index bbf6d473e50c..8faa1a9aaeb9 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -1,23 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Common functions for in-kernel torture tests. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, you can access it online at - * http://www.gnu.org/licenses/gpl-2.0.html. - * * Copyright (C) IBM Corporation, 2014 * - * Author: Paul E. McKenney + * Author: Paul E. McKenney * Based on kernel/rcu/torture.c. */ @@ -53,7 +40,7 @@ #include "rcu/rcu.h" MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Paul E. McKenney "); +MODULE_AUTHOR("Paul E. McKenney "); static char *torture_type; static int verbose; @@ -75,6 +62,7 @@ static DEFINE_MUTEX(fullstop_mutex); static struct task_struct *onoff_task; static long onoff_holdoff; static long onoff_interval; +static torture_ofl_func *onoff_f; static long n_offline_attempts; static long n_offline_successes; static unsigned long sum_offline; @@ -118,6 +106,8 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, pr_alert("%s" TORTURE_FLAG "torture_onoff task: offlined %d\n", torture_type, cpu); + if (onoff_f) + onoff_f(); (*n_offl_successes)++; delta = jiffies - starttime; *sum_offl += delta; @@ -243,11 +233,12 @@ stop: /* * Initiate online-offline handling. */ -int torture_onoff_init(long ooholdoff, long oointerval) +int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) { #ifdef CONFIG_HOTPLUG_CPU onoff_holdoff = ooholdoff; onoff_interval = oointerval; + onoff_f = f; if (onoff_interval <= 0) return 0; return torture_create_kthread(torture_onoff, NULL, onoff_task); diff --git a/tools/testing/selftests/rcutorture/bin/nolibc.h b/tools/include/nolibc/nolibc.h similarity index 94% rename from tools/testing/selftests/rcutorture/bin/nolibc.h rename to tools/include/nolibc/nolibc.h index f98f5b92d3eb..1708e9f9f8aa 100644 --- a/tools/testing/selftests/rcutorture/bin/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -3,7 +3,85 @@ * Copyright (C) 2017-2018 Willy Tarreau */ -/* some archs (at least aarch64) don't expose the regular syscalls anymore by +/* + * This file is designed to be used as a libc alternative for minimal programs + * with very limited requirements. It consists of a small number of syscall and + * type definitions, and the minimal startup code needed to call main(). + * All syscalls are declared as static functions so that they can be optimized + * away by the compiler when not used. + * + * Syscalls are split into 3 levels: + * - The lower level is the arch-specific syscall() definition, consisting in + * assembly code in compound expressions. These are called my_syscall0() to + * my_syscall6() depending on the number of arguments. The MIPS + * implementation is limited to 5 arguments. All input arguments are cast + * to a long stored in a register. These expressions always return the + * syscall's return value as a signed long value which is often either a + * pointer or the negated errno value. + * + * - The second level is mostly architecture-independent. It is made of + * static functions called sys_() which rely on my_syscallN() + * depending on the syscall definition. These functions are responsible + * for exposing the appropriate types for the syscall arguments (int, + * pointers, etc) and for setting the appropriate return type (often int). + * A few of them are architecture-specific because the syscalls are not all + * mapped exactly the same among architectures. For example, some archs do + * not implement select() and need pselect6() instead, so the sys_select() + * function will have to abstract this. + * + * - The third level is the libc call definition. It exposes the lower raw + * sys_() calls in a way that looks like what a libc usually does, + * takes care of specific input values, and of setting errno upon error. + * There can be minor variations compared to standard libc calls. For + * example the open() call always takes 3 args here. + * + * The errno variable is declared static and unused. This way it can be + * optimized away if not used. However this means that a program made of + * multiple C files may observe different errno values (one per C file). For + * the type of programs this project targets it usually is not a problem. The + * resulting program may even be reduced by defining the NOLIBC_IGNORE_ERRNO + * macro, in which case the errno value will never be assigned. + * + * Some stdint-like integer types are defined. These are valid on all currently + * supported architectures, because signs are enforced, ints are assumed to be + * 32 bits, longs the size of a pointer and long long 64 bits. If more + * architectures have to be supported, this may need to be adapted. + * + * Some macro definitions like the O_* values passed to open(), and some + * structures like the sys_stat struct depend on the architecture. + * + * The definitions start with the architecture-specific parts, which are picked + * based on what the compiler knows about the target architecture, and are + * completed with the generic code. Since it is the compiler which sets the + * target architecture, cross-compiling normally works out of the box without + * having to specify anything. + * + * Finally some very common libc-level functions are provided. It is the case + * for a few functions usually found in string.h, ctype.h, or stdlib.h. Nothing + * is currently provided regarding stdio emulation. + * + * The macro NOLIBC is always defined, so that it is possible for a program to + * check this macro to know if it is being built against and decide to disable + * some features or simply not to include some standard libc files. + * + * Ideally this file should be split in multiple files for easier long term + * maintenance, but provided as a single file as it is now, it's quite + * convenient to use. Maybe some variations involving a set of includes at the + * top could work. + * + * A simple static executable may be built this way : + * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ + * -static -include nolibc.h -lgcc -o hello hello.c + * + * A very useful calling convention table may be found here : + * http://man7.org/linux/man-pages/man2/syscall.2.html + * + * This doc is quite convenient though not necessarily up to date : + * https://w3challs.com/syscalls/ + * + */ + +/* Some archs (at least aarch64) don't expose the regular syscalls anymore by * default, either because they have an "_at" replacement, or because there are * more modern alternatives. For now we'd rather still use them. */ @@ -19,18 +97,6 @@ #define NOLIBC -/* Build a static executable this way : - * $ gcc -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \ - * -static -include nolibc.h -lgcc -o hello hello.c - * - * Useful calling convention table found here : - * http://man7.org/linux/man-pages/man2/syscall.2.html - * - * This doc is even better : - * https://w3challs.com/syscalls/ - */ - - /* this way it will be removed if unused */ static int errno; @@ -81,9 +147,9 @@ typedef signed long time_t; /* for poll() */ struct pollfd { - int fd; - short int events; - short int revents; + int fd; + short int events; + short int revents; }; /* for select() */ @@ -239,7 +305,7 @@ struct stat { "syscall\n" \ : "=a" (_ret) \ : "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -255,7 +321,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -272,7 +338,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), "r"(_arg2), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -290,7 +356,7 @@ struct stat { : "=a" (_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -1006,7 +1072,7 @@ struct sys_stat_struct { : "=r"(_num), "=r"(_arg4) \ : "r"(_num) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1025,7 +1091,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1045,7 +1111,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1066,7 +1132,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1087,7 +1153,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) @@ -1110,7 +1176,7 @@ struct sys_stat_struct { : "0"(_num), \ "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5) \ : "memory", "cc", "at", "v1", "hi", "lo", \ - \ + "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \ ); \ _arg4 ? -_num : _num; \ }) diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh index da298394daa2..83552bb007b4 100755 --- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh @@ -40,17 +40,24 @@ mkdir $T cat > $T/init << '__EOF___' #!/bin/sh # Run in userspace a few milliseconds every second. This helps to -# exercise the NO_HZ_FULL portions of RCU. +# exercise the NO_HZ_FULL portions of RCU. The 192 instances of "a" was +# empirically shown to give a nice multi-millisecond burst of user-mode +# execution on a 2GHz CPU, as desired. Modern CPUs will vary from a +# couple of milliseconds up to perhaps 100 milliseconds, which is an +# acceptable range. +# +# Why not calibrate an exact delay? Because within this initrd, we +# are restricted to Bourne-shell builtins, which as far as I know do not +# provide any means of obtaining a fine-grained timestamp. + +a4="a a a a" +a16="$a4 $a4 $a4 $a4" +a64="$a16 $a16 $a16 $a16" +a192="$a64 $a64 $a64" while : do q= - for i in \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a + for i in $a192 do q="$q $i" done @@ -124,8 +131,8 @@ if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \ | grep -q '^yes'; then # architecture supported by nolibc ${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \ - -nostdlib -include ../bin/nolibc.h -lgcc -s -static -Os \ - -o init init.c + -nostdlib -include ../../../../include/nolibc/nolibc.h \ + -lgcc -s -static -Os -o init init.c else ${CROSS_COMPILE}gcc -s -static -Os -o init init.c fi diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5ecea812cb6a..28de87ff9f51 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4083,7 +4083,7 @@ static int kvm_suspend(void) static void kvm_resume(void) { if (kvm_usage_count) { - WARN_ON(raw_spin_is_locked(&kvm_count_lock)); + lockdep_assert_held(&kvm_count_lock); hardware_enable_nolock(NULL); } }