From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752518AbbH2Doo (ORCPT ); Fri, 28 Aug 2015 23:44:44 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:38684 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752199AbbH2DoO (ORCPT ); Fri, 28 Aug 2015 23:44:14 -0400 X-Helo: d03dlp02.boulder.ibm.com X-MailFrom: paulmck@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH RFC tip/core/rcu 2/9] rcu_sync: Simplify rcu_sync using new rcu_sync_ops structure Date: Fri, 28 Aug 2015 20:35:54 -0700 Message-Id: <1440819361-20251-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1440819361-20251-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150829032643.GA19166@linux.vnet.ibm.com> <1440819361-20251-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15082903-0005-0000-0000-000017A17D06 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleg Nesterov This commit adds the new struct rcu_sync_ops which holds sync/call methods, and turns the function pointers in rcu_sync_struct into an array of struct rcu_sync_ops. This simplifies the "init" helpers by collapsing a switch statement and explicit multiple definitions into a simple assignment and a helper macro, respectively. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Paul E. McKenney --- include/linux/rcu_sync.h | 60 +++++++++++++++++++----------------------------- kernel/rcu/sync.c | 42 +++++++++++++++++---------------- 2 files changed, 45 insertions(+), 57 deletions(-) diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h index cb044df2e21c..c6d2272c4459 100644 --- a/include/linux/rcu_sync.h +++ b/include/linux/rcu_sync.h @@ -26,6 +26,8 @@ #include #include +enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC }; + /* Structure to mediate between updaters and fastpath-using readers. */ struct rcu_sync { int gp_state; @@ -35,43 +37,9 @@ struct rcu_sync { int cb_state; struct rcu_head cb_head; - void (*sync)(void); - void (*call)(struct rcu_head *, void (*)(struct rcu_head *)); + enum rcu_sync_type gp_type; }; -#define ___RCU_SYNC_INIT(name) \ - .gp_state = 0, \ - .gp_count = 0, \ - .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \ - .cb_state = 0 - -#define __RCU_SCHED_SYNC_INIT(name) { \ - ___RCU_SYNC_INIT(name), \ - .sync = synchronize_sched, \ - .call = call_rcu_sched, \ -} - -#define __RCU_BH_SYNC_INIT(name) { \ - ___RCU_SYNC_INIT(name), \ - .sync = synchronize_rcu_bh, \ - .call = call_rcu_bh, \ -} - -#define __RCU_SYNC_INIT(name) { \ - ___RCU_SYNC_INIT(name), \ - .sync = synchronize_rcu, \ - .call = call_rcu, \ -} - -#define DEFINE_RCU_SCHED_SYNC(name) \ - struct rcu_sync name = __RCU_SCHED_SYNC_INIT(name) - -#define DEFINE_RCU_BH_SYNC(name) \ - struct rcu_sync name = __RCU_BH_SYNC_INIT(name) - -#define DEFINE_RCU_SYNC(name) \ - struct rcu_sync name = __RCU_SYNC_INIT(name) - /** * rcu_sync_is_idle() - Are readers permitted to use their fastpaths? * @rsp: Pointer to rcu_sync structure to use for synchronization @@ -85,10 +53,28 @@ static inline bool rcu_sync_is_idle(struct rcu_sync *rsp) return !rsp->gp_state; /* GP_IDLE */ } -enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC }; - extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type); extern void rcu_sync_enter(struct rcu_sync *); extern void rcu_sync_exit(struct rcu_sync *); +#define __RCU_SYNC_INITIALIZER(name, type) { \ + .gp_state = 0, \ + .gp_count = 0, \ + .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \ + .cb_state = 0, \ + .gp_type = type, \ + } + +#define __DEFINE_RCU_SYNC(name, type) \ + struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type) + +#define DEFINE_RCU_SYNC(name) \ + __DEFINE_RCU_SYNC(name, RCU_SYNC) + +#define DEFINE_RCU_SCHED_SYNC(name) \ + __DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC) + +#define DEFINE_RCU_BH_SYNC(name) \ + __DEFINE_RCU_SYNC(name, RCU_BH_SYNC) + #endif /* _LINUX_RCU_SYNC_H_ */ diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index 0a11df43be23..5a9aa4c394f1 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -23,6 +23,24 @@ #include #include +static const struct { + void (*sync)(void); + void (*call)(struct rcu_head *, void (*)(struct rcu_head *)); +} gp_ops[] = { + [RCU_SYNC] = { + .sync = synchronize_rcu, + .call = call_rcu, + }, + [RCU_SCHED_SYNC] = { + .sync = synchronize_sched, + .call = call_rcu_sched, + }, + [RCU_BH_SYNC] = { + .sync = synchronize_rcu_bh, + .call = call_rcu_bh, + }, +}; + enum { GP_IDLE = 0, GP_PENDING, GP_PASSED }; enum { CB_IDLE = 0, CB_PENDING, CB_REPLAY }; @@ -37,23 +55,7 @@ void rcu_sync_init(struct rcu_sync *rsp, enum rcu_sync_type type) { memset(rsp, 0, sizeof(*rsp)); init_waitqueue_head(&rsp->gp_wait); - - switch (type) { - case RCU_SYNC: - rsp->sync = synchronize_rcu; - rsp->call = call_rcu; - break; - - case RCU_SCHED_SYNC: - rsp->sync = synchronize_sched; - rsp->call = call_rcu_sched; - break; - - case RCU_BH_SYNC: - rsp->sync = synchronize_rcu_bh; - rsp->call = call_rcu_bh; - break; - } + rsp->gp_type = type; } /** @@ -85,7 +87,7 @@ void rcu_sync_enter(struct rcu_sync *rsp) BUG_ON(need_wait && need_sync); if (need_sync) { - rsp->sync(); + gp_ops[rsp->gp_type].sync(); rsp->gp_state = GP_PASSED; wake_up_all(&rsp->gp_wait); } else if (need_wait) { @@ -138,7 +140,7 @@ static void rcu_sync_func(struct rcu_head *rcu) * to catch a later GP. */ rsp->cb_state = CB_PENDING; - rsp->call(&rsp->cb_head, rcu_sync_func); + gp_ops[rsp->gp_type].call(&rsp->cb_head, rcu_sync_func); } else { /* * We're at least a GP after rcu_sync_exit(); eveybody will now @@ -166,7 +168,7 @@ void rcu_sync_exit(struct rcu_sync *rsp) if (!--rsp->gp_count) { if (rsp->cb_state == CB_IDLE) { rsp->cb_state = CB_PENDING; - rsp->call(&rsp->cb_head, rcu_sync_func); + gp_ops[rsp->gp_type].call(&rsp->cb_head, rcu_sync_func); } else if (rsp->cb_state == CB_PENDING) { rsp->cb_state = CB_REPLAY; } -- 1.8.1.5