From 812443865c5fc255363d4a684a62c086af1addca Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Nov 2014 14:19:28 -0500 Subject: [PATCH] sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it ...also make the manipulation of sp_all_threads list use RCU-friendly functions. Signed-off-by: Jeff Layton Tested-by: Chris Worley Signed-off-by: J. Bruce Fields --- include/linux/sunrpc/svc.h | 2 ++ include/trace/events/sunrpc.h | 3 ++- net/sunrpc/svc.c | 10 ++++++---- 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 5f0ab39..7f80a99 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -223,6 +223,7 @@ static inline void svc_putu32(struct kvec *iov, __be32 val) struct svc_rqst { struct list_head rq_list; /* idle list */ struct list_head rq_all; /* all threads list */ + struct rcu_head rq_rcu_head; /* for RCU deferred kfree */ struct svc_xprt * rq_xprt; /* transport ptr */ struct sockaddr_storage rq_addr; /* peer address */ @@ -262,6 +263,7 @@ struct svc_rqst { #define RQ_SPLICE_OK (4) /* turned off in gss privacy * to prevent encrypting page * cache pages */ +#define RQ_VICTIM (5) /* about to be shut down */ unsigned long rq_flags; /* flags field */ void * rq_argp; /* decoded arguments */ diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h index 5848fc2..08a5fed 100644 --- a/include/trace/events/sunrpc.h +++ b/include/trace/events/sunrpc.h @@ -418,7 +418,8 @@ TRACE_EVENT(xs_tcp_data_recv, { (1UL << RQ_LOCAL), "RQ_LOCAL"}, \ { (1UL << RQ_USEDEFERRAL), "RQ_USEDEFERRAL"}, \ { (1UL << RQ_DROPME), "RQ_DROPME"}, \ - { (1UL << RQ_SPLICE_OK), "RQ_SPLICE_OK"}) + { (1UL << RQ_SPLICE_OK), "RQ_SPLICE_OK"}, \ + { (1UL << RQ_VICTIM), "RQ_VICTIM"}) TRACE_EVENT(svc_recv, TP_PROTO(struct svc_rqst *rqst, int status), diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index a06a891..b90d1bc 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -616,7 +616,7 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) serv->sv_nrthreads++; spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads++; - list_add(&rqstp->rq_all, &pool->sp_all_threads); + list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads); spin_unlock_bh(&pool->sp_lock); rqstp->rq_server = serv; rqstp->rq_pool = pool; @@ -684,7 +684,8 @@ found_pool: * so we don't try to kill it again. */ rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all); - list_del_init(&rqstp->rq_all); + set_bit(RQ_VICTIM, &rqstp->rq_flags); + list_del_rcu(&rqstp->rq_all); task = rqstp->rq_task; } spin_unlock_bh(&pool->sp_lock); @@ -782,10 +783,11 @@ svc_exit_thread(struct svc_rqst *rqstp) spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads--; - list_del(&rqstp->rq_all); + if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags)) + list_del_rcu(&rqstp->rq_all); spin_unlock_bh(&pool->sp_lock); - kfree(rqstp); + kfree_rcu(rqstp, rq_rcu_head); /* Release the server */ if (serv) -- 2.7.4