/* * IPVS: Round-Robin Scheduling module * * Authors: Wensong Zhang * Peter Kese * * 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. * * Fixes/Changes: * Wensong Zhang : changed the ip_vs_rr_schedule to return dest * Julian Anastasov : fixed the NULL pointer access bug in debugging * Wensong Zhang : changed some comestics things for debugging * Wensong Zhang : changed for the d-linked destination list * Wensong Zhang : added the ip_vs_rr_update_svc * Wensong Zhang : added any dest with weight=0 is quiesced * */ #define KMSG_COMPONENT "IPVS" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include #include static int ip_vs_rr_init_svc(struct ip_vs_service *svc) { svc->sched_data = &svc->destinations; return 0; } static int ip_vs_rr_del_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest) { struct list_head *p; spin_lock_bh(&svc->sched_lock); p = (struct list_head *) svc->sched_data; /* dest is already unlinked, so p->prev is not valid but * p->next is valid, use it to reach previous entry. */ if (p == &dest->n_list) svc->sched_data = p->next->prev; spin_unlock_bh(&svc->sched_lock); return 0; } /* * Round-Robin Scheduling */ static struct ip_vs_dest * ip_vs_rr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb, struct ip_vs_iphdr *iph) { struct list_head *p; struct ip_vs_dest *dest, *last; int pass = 0; IP_VS_DBG(6, "%s(): Scheduling...\n", __func__); spin_lock_bh(&svc->sched_lock); p = (struct list_head *) svc->sched_data; last = dest = list_entry(p, struct ip_vs_dest, n_list); do { list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) { if (!(dest->flags & IP_VS_DEST_F_OVERLOAD) && atomic_read(&dest->weight) > 0) /* HIT */ goto out; if (dest == last) goto stop; } pass++; /* Previous dest could be unlinked, do not loop forever. * If we stay at head there is no need for 2nd pass. */ } while (pass < 2 && p != &svc->destinations); stop: spin_unlock_bh(&svc->sched_lock); ip_vs_scheduler_err(svc, "no destination available"); return NULL; out: svc->sched_data = &dest->n_list; spin_unlock_bh(&svc->sched_lock); IP_VS_DBG_BUF(6, "RR: server %s:%u " "activeconns %d refcnt %d weight %d\n", IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port), atomic_read(&dest->activeconns), atomic_read(&dest->refcnt), atomic_read(&dest->weight)); return dest; } static struct ip_vs_scheduler ip_vs_rr_scheduler = { .name = "rr", /* name */ .refcnt = ATOMIC_INIT(0), .module = THIS_MODULE, .n_list = LIST_HEAD_INIT(ip_vs_rr_scheduler.n_list), .init_service = ip_vs_rr_init_svc, .add_dest = NULL, .del_dest = ip_vs_rr_del_dest, .schedule = ip_vs_rr_schedule, }; static int __init ip_vs_rr_init(void) { return register_ip_vs_scheduler(&ip_vs_rr_scheduler); } static void __exit ip_vs_rr_cleanup(void) { unregister_ip_vs_scheduler(&ip_vs_rr_scheduler); synchronize_rcu(); } module_init(ip_vs_rr_init); module_exit(ip_vs_rr_cleanup); MODULE_LICENSE("GPL"); den' name='id' value='d7df2443cd5f67fc6ee7c05a88e4996e8177f91b'/>
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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2017-02-03 17:10:28 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2017-02-08 23:36:29 +1100
commitd7df2443cd5f67fc6ee7c05a88e4996e8177f91b (patch)
tree098a7c0ca4fceb8a65cb1f693c9d71990388933d /net/ipv4/tcp_htcp.c
parenta0615a16f7d0ceb5804d295203c302d496d8ee91 (diff)
powerpc/mm: Fix spurrious segfaults on radix with autonuma
When autonuma (Automatic NUMA balancing) marks a PTE inaccessible it clears all the protection bits but leave the PTE valid. With the Radix MMU, an attempt at executing from such a PTE will take a fault with bit 35 of SRR1 set "SRR1_ISI_N_OR_G". It is thus incorrect to treat all such faults as errors. We should pass them to handle_mm_fault() for autonuma to deal with. The case of pages that are really not executable is handled by the existing test for VM_EXEC further down. That leaves us with catching the kernel attempts at executing user pages. We can catch that earlier, even before we do find_vma. It is never valid on powerpc for the kernel to take an exec fault to begin with. So fold that test with the existing test for the kernel faulting on kernel addresses to bail out early. Fixes: 1d18ad026844 ("powerpc/mm: Detect instruction fetch denied and report") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'net/ipv4/tcp_htcp.c')