From 82e8c565be8a72957570d7da8dd9b441db7bb648 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 21 Aug 2015 19:42:47 +0200 Subject: rcu_sync: Simplify rcu_sync using new rcu_sync_ops structure 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 Reviewed-by: Josh Triplett --- kernel/rcu/sync.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'kernel/rcu/sync.c') 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; } -- cgit