From aa4a221875873d2a1f9656cb7fd7e545e952b4fa Mon Sep 17 00:00:00 2001 From: Vince Weaver Date: Fri, 3 Jun 2011 17:54:40 -0400 Subject: perf: Comment /proc/sys/kernel/perf_event_paranoid to be part of user ABI Turns out that distro packages use this file as an indicator of the perf event subsystem - this is easier to check for from scripts than the existence of the system call. This is easy enough to keep around for the kernel, so add a comment to make sure it stays so. Signed-off-by: Vince Weaver Cc: David Ahern Cc: Peter Zijlstra Cc: paulus@samba.org Cc: acme@redhat.com Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1106031751170.29381@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 4fc92445a29c..f175d98bd355 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -938,6 +938,12 @@ static struct ctl_table kern_table[] = { }, #endif #ifdef CONFIG_PERF_EVENTS + /* + * User-space scripts rely on the existence of this file + * as a feature check for perf_events being enabled. + * + * So it's an ABI, do not remove! + */ { .procname = "perf_event_paranoid", .data = &sysctl_perf_event_paranoid, -- cgit v1.2.3 From a95cded32de3deae13af34715200532e6823cc9f Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 1 May 2011 23:21:00 -0700 Subject: sysctl,rcu: Convert call_rcu(free_head) to kfree The RCU callback free_head just calls kfree(), so we can use kfree_rcu() instead of call_rcu(). Signed-off-by: Paul E. McKenney Cc: Andrew Morton Reviewed-by: Josh Triplett --- kernel/sysctl.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f175d98bd355..11d65b531e50 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1590,16 +1590,11 @@ void sysctl_head_get(struct ctl_table_header *head) spin_unlock(&sysctl_lock); } -static void free_head(struct rcu_head *rcu) -{ - kfree(container_of(rcu, struct ctl_table_header, rcu)); -} - void sysctl_head_put(struct ctl_table_header *head) { spin_lock(&sysctl_lock); if (!--head->count) - call_rcu(&head->rcu, free_head); + kfree_rcu(head, rcu); spin_unlock(&sysctl_lock); } @@ -1971,10 +1966,10 @@ void unregister_sysctl_table(struct ctl_table_header * header) start_unregistering(header); if (!--header->parent->count) { WARN_ON(1); - call_rcu(&header->parent->rcu, free_head); + kfree_rcu(header->parent, rcu); } if (!--header->count) - call_rcu(&header->rcu, free_head); + kfree_rcu(header, rcu); spin_unlock(&sysctl_lock); } -- cgit v1.2.3