/* * 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 * * For detailed explanation of Read-Copy Update mechanism see - * Documentation/RCU */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "rcu.h" /* Forward declarations for tiny_plugin.h. */ struct rcu_ctrlblk; static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp); static void rcu_process_callbacks(struct softirq_action *unused); static void __call_rcu(struct rcu_head *head, rcu_callback_t func, struct rcu_ctrlblk *rcp); #include "tiny_plugin.h" #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) /* * Test whether RCU thinks that the current CPU is idle. */ bool notrace __rcu_is_watching(void) { return true; } EXPORT_SYMBOL(__rcu_is_watching); #endif /* defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */ /* * Helper function for rcu_sched_qs() and rcu_bh_qs(). * Also irqs are disabled to avoid confusion due to interrupt handlers * invoking call_rcu(). */ static int rcu_qsctr_help(struct rcu_ctrlblk *rcp) { RCU_TRACE(reset_cpu_stall_ticks(rcp)); if (rcp->donetail != rcp->curtail) { rcp->donetail = rcp->curtail; return 1; } return 0; } /* * Record an rcu quiescent state. And an rcu_bh quiescent state while we * are at it, given that any rcu quiescent state is also an rcu_bh * quiescent state. Use "+" instead of "||" to defeat short circuiting. */ void rcu_sched_qs(void) { unsigned long flags; local_irq_save(flags); if (rcu_qsctr_help(&rcu_sched_ctrlblk) + rcu_qsctr_help(&rcu_bh_ctrlblk)) raise_softirq(RCU_SOFTIRQ); local_irq_restore(flags); } /* * Record an rcu_bh quiescent state. */ void rcu_bh_qs(void) { unsigned long flags; local_irq_save(flags); if (rcu_qsctr_help(&rcu_bh_ctrlblk)) raise_softirq(RCU_SOFTIRQ); local_irq_restore(flags); } /* * Check to see if the scheduling-clock interrupt came from an extended * quiescent state, and, if so, tell RCU about it. This function must * be called from hardirq context. It is normally called from the * scheduling-clock interrupt. */ void rcu_check_callbacks(int user) { RCU_TRACE(check_cpu_stalls()); if (user) rcu_sched_qs(); else if (!in_softirq()) rcu_bh_qs(); if (user) rcu_note_voluntary_context_switch(current); } /* * Invoke the RCU callbacks on the specified rcu_ctrlkblk structure * whose grace period has elapsed. */ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp) { const char *rn = NULL; struct rcu_head *next, *list; unsigned long flags; RCU_TRACE(int cb_count = 0); /* Move the ready-to-invoke callbacks to a local list. */ local_irq_save(flags); if (rcp->donetail == &rcp->rcucblist) { /* No callbacks ready, so just leave. */ local_irq_restore(flags); return; } RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1)); list = rcp->rcucblist; rcp->rcucblist = *rcp->donetail; *rcp->donetail = NULL; if (rcp->curtail == rcp->donetail) rcp->curtail = &rcp->rcucblist; rcp->donetail = &rcp->rcucblist; local_irq_restore(flags); /* Invoke the callbacks on the local list. */ RCU_TRACE(rn = rcp->name); while (list) { next = list->next; prefetch(next); debug_rcu_head_unqueue(list); local_bh_disable(); __rcu_reclaim(rn, list); local_bh_enable(); list = next; RCU_TRACE(cb_count++); } RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count)); RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count, 0, need_resched(), is_idle_task(current), false)); } static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused) { __rcu_process_callbacks(&rcu_sched_ctrlblk); __rcu_process_callbacks(&rcu_bh_ctrlblk); } /* * Wait for a grace period to elapse. But it is illegal to invoke * synchronize_sched() from within an RCU read-side critical section. * Therefore, any legal call to synchronize_sched() is a quiescent * state, and so on a UP system, synchronize_sched() need do nothing. * Ditto for synchronize_rcu_bh(). (But Lai Jiangshan points out the * benefits of doing might_sleep() to reduce latency.) * * Cool, huh? (Due to Josh Triplett.) */ void synchronize_sched(void) { RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || lock_is_held(&rcu_lock_map) || lock_is_held(&rcu_sched_lock_map), "Illegal synchronize_sched() in RCU read-side critical section"); } EXPORT_SYMBOL_GPL(synchronize_sched); /* * Helper function for call_rcu() and call_rcu_bh(). */ static void __call_rcu(struct rcu_head *head, rcu_callback_t func, struct rcu_ctrlblk *rcp) { unsigned long flags; debug_rcu_head_queue(head); head->func = func; head->next = NULL; local_irq_save(flags); *rcp->curtail = head; rcp->curtail = &head->next; RCU_TRACE(rcp->qlen++); local_irq_restore(flags); if (unlikely(is_idle_task(current))) { /* force scheduling for rcu_sched_qs() */ resched_cpu(0); } } /* * Post an RCU callback to be invoked after the end of an RCU-sched grace * period. But since we have but one CPU, that would be after any * quiescent state. */ void call_rcu_sched(struct rcu_head *head, rcu_callback_t func) { __call_rcu(head, func, &rcu_sched_ctrlblk); } EXPORT_SYMBOL_GPL(call_rcu_sched); /* * Post an RCU bottom-half callback to be invoked after any subsequent * quiescent state. */ void call_rcu_bh(struct rcu_head *head, rcu_callback_t func) { __call_rcu(head, func, &rcu_bh_ctrlblk); } EXPORT_SYMBOL_GPL(call_rcu_bh); void __init rcu_init(void) { open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); RCU_TRACE(reset_cpu_stall_ticks(&rcu_sched_ctrlblk)); RCU_TRACE(reset_cpu_stall_ticks(&rcu_bh_ctrlblk)); rcu_early_boot_tests(); } clude?h=nds-private-remove&id=14b89f36eed2993670906a3991bca496a5ebf1a6'>net: dsa: Rename and export dev_to_net_device()Florian Fainelli1-0/+1 2017-02-07net: phy: Add 2000base-x, 2500base-x and rxaui modesAndrew Lunn1-0/+9 2017-02-07virtio_net: refactor freeze/restore logic into virtnet reset logicJohn Fastabend1-0/+4 2017-02-06net: dsa: introduce bridge notifierVivien Didelot1-0/+10 2017-02-06net: dsa: add switch notifierVivien Didelot1-0/+7 2017-02-06net-next: treewide use is_vlan_dev() helper function.Parav Pandit1-4/+2 2017-02-06net: remove ndo_neigh_{construct, destroy} from stacked devicesIdo Schimmel1-4/+0 2017-02-06net/mlx5: TX WQE updateSaeed Mahameed2-3/+16 2017-02-06net/mlx5: Configure cache line size for start and end paddingDaniel Jurgens1-2/+4 2017-02-06can: rx-offload: Add support for timestamp based irq offloadingMarc Kleine-Budde1-1/+9 2017-02-06can: rx-offload: Add support for HW fifo based irq offloadingDavid Jander1-0/+51 2017-02-06net/mlx5: Fix static checker warningsOr Gerlitz1-1/+2 2017-02-05net: remove __napi_complete()Eric Dumazet1-1/+0 2017-02-04net: ipv6: Change notifications for multipath add to RTA_MULTIPATHDavid Ahern1-0/+1 2017-02-04net: ipv6: Allow shorthand delete of all nexthops in multipath routeDavid Ahern1-1/+3 2017-02-03net: remove support for per driver ndo_busy_poll()Eric Dumazet2-5/+0 2017-02-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller11-40/+60 2017-02-03sched: cls_flower: expose priority to offloading netdeviceJiri Pirko1-0/+1 2017-02-03lib: Introduce priority array area managerJiri Pirko1-0/+76 2017-02-03list: introduce list_for_each_entry_from_reverse helperJiri Pirko1-0/+13 2017-02-03trace: rename trace_print_hex_seq arg and add kdocDaniel Borkmann2-3/+3 2017-02-03bridge: uapi: add per vlan tunnel infoRoopa Prabhu3-0/+13 2017-02-03vxlan: support fdb and learning in COLLECT_METADATA modeRoopa Prabhu1-0/+1 2017-02-03ip_tunnels: new IP_TUNNEL_INFO_BRIDGE flag for ip_tunnel_info modeRoopa Prabhu1-0/+1 2017-02-03net/sched: act_ife: Change to use ife moduleYotam Gigi2-10/+1 2017-02-03net: Introduce ife encapsulation moduleYotam Gigi3-0/+70 2017-02-03net/sched: act_ife: Unexport ife_tlv_meta_encodeYotam Gigi1-2/+0 2017-02-03tcp: add tcp_mss_clamp() helperEric Dumazet1-0/+9 2017-02-02net: add LINUX_MIB_PFMEMALLOCDROP counterEric Dumazet1-0/+1 2017-02-02net: phy: marvell: Add support for 88e1545 PHYAndrew Lunn1-0/+1 2017-02-02unix: add ioctl to open a unix socket file with O_PATHAndrey Vagin1-0/+2 2017-02-02net: phy: Marvell: Add mv88e6390 internal PHYAndrew Lunn1-0/+6 2017-02-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller9-30/+40 2017-02-02netfilter: allow logging from non-init namespacesMichal Kubeček1-0/+3 2017-02-02ipvs: free ip_vs_dest structs when refcnt=0David Windsor1-1/+1 2017-02-02netfilter: merge ctinfo into nfct pointer storage areaFlorian Westphal2-17/+15 2017-02-02netfilter: guarantee 8 byte minalign for template addressesFlorian Westphal1-0/+2 2017-02-02netfilter: add and use nf_ct_set helperFlorian Westphal2-2/+9 2017-02-02skbuff: add and use skb_nfct helperFlorian Westphal2-4/+11 2017-02-02netfilter: reduce direct skb->nfct usageFlorian Westphal1-3/+6 2017-02-02netfilter: conntrack: no need to pass ctinfo to error handlerFlorian Westphal1-1/+1