Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qg0-f41.google.com ([209.85.192.41]:48043 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750755AbaKUTTk (ORCPT ); Fri, 21 Nov 2014 14:19:40 -0500 Received: by mail-qg0-f41.google.com with SMTP id j5so4234317qga.28 for ; Fri, 21 Nov 2014 11:19:40 -0800 (PST) From: Jeff Layton To: bfields@fieldses.org Cc: Chris Worley , linux-nfs@vger.kernel.org Subject: [PATCH 1/4] sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it Date: Fri, 21 Nov 2014 14:19:28 -0500 Message-Id: <1416597571-4265-2-git-send-email-jlayton@primarydata.com> In-Reply-To: <1416597571-4265-1-git-send-email-jlayton@primarydata.com> References: <1416597571-4265-1-git-send-email-jlayton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: ...also make the manipulation of sp_all_threads list use RCU-friendly functions. Signed-off-by: Jeff Layton Tested-by: Chris Worley --- 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 5f0ab39bf7c3..7f80a99c59e4 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 5848fc235869..08a5fed50f34 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 5d9a443d21f6..4edef32f3b9f 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) -- 2.1.0