From 4e6ea4ef56f9425cd239ffdb6be45b3aeeb347fd Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 14 Aug 2018 14:41:49 -0700 Subject: srcu: Make early-boot call_srcu() reuse workqueue lists Allocating a list_head structure that is almost never used, and, when used, is used only during early boot (rcu_init() and earlier), is a bit wasteful. This commit therefore eliminates that list_head in favor of the one in the work_struct structure. This is safe because the work_struct structure cannot be used until after rcu_init() returns. Reported-by: Steven Rostedt Signed-off-by: Paul E. McKenney Cc: Tejun Heo Cc: Lai Jiangshan Tested-by: Steven Rostedt (VMware) --- kernel/rcu/srcutiny.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/rcu/srcutiny.c') diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index d233f0c63f6f..b46e6683f8c9 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -48,7 +48,7 @@ static int init_srcu_struct_fields(struct srcu_struct *sp) sp->srcu_gp_waiting = false; sp->srcu_idx = 0; INIT_WORK(&sp->srcu_work, srcu_drive_gp); - INIT_LIST_HEAD(&sp->srcu_boot_entry); + INIT_LIST_HEAD(&sp->srcu_work.entry); return 0; } @@ -185,8 +185,8 @@ void call_srcu(struct srcu_struct *sp, struct rcu_head *rhp, if (!READ_ONCE(sp->srcu_gp_running)) { if (likely(srcu_init_done)) schedule_work(&sp->srcu_work); - else if (list_empty(&sp->srcu_boot_entry)) - list_add(&sp->srcu_boot_entry, &srcu_boot_list); + else if (list_empty(&sp->srcu_work.entry)) + list_add(&sp->srcu_work.entry, &srcu_boot_list); } } EXPORT_SYMBOL_GPL(call_srcu); @@ -224,8 +224,8 @@ void __init srcu_init(void) srcu_init_done = true; while (!list_empty(&srcu_boot_list)) { sp = list_first_entry(&srcu_boot_list, - struct srcu_struct, srcu_boot_entry); - list_del_init(&sp->srcu_boot_entry); + struct srcu_struct, srcu_work.entry); + list_del_init(&sp->srcu_work.entry); schedule_work(&sp->srcu_work); } } -- cgit