Re: [PATCH 3/4 V2] futex: free_pi_state outside of hb->lock sections

[Darren Hart <dvhltc@us.ibm.com>]

Apologies, mangled a rebase and this patch had bits of 4/4 in it.
Corrected below:


>From f40b8e684df6ed2b1ba9167cad3922ab43f4a717 Mon Sep 17 00:00:00 2001
From: Darren Hart <dvhltc@us.ibm.com>
Date: Fri, 9 Jul 2010 17:07:10 -0400
Subject: [PATCH 3/4 V2] futex: free_pi_state outside of hb->lock sections

free_pi_state() calls kfree() and might sleep. To prepare for raw hb->locks,
get the calls to free_pi_state() out of the hb->lock() sections.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
---
 kernel/futex.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index a6cec32..2cd58a2 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1339,7 +1339,6 @@ retry_private:
 			} else if (ret) {
 				/* -EDEADLK */
 				this->pi_state = NULL;
-				free_pi_state(pi_state);
 				goto out_unlock;
 			}
 		}
@@ -1483,16 +1482,19 @@ retry:
  */
 static void unqueue_me_pi(struct futex_q *q)
 {
+	struct futex_pi_state *pi_state = NULL;
+
 	WARN_ON(plist_node_empty(&q->list));
 	plist_del(&q->list, &q->list.plist);
 
 	BUG_ON(!q->pi_state);
-	free_pi_state(q->pi_state);
+	pi_state = q->pi_state;
 	q->pi_state = NULL;
 
 	spin_unlock(q->lock_ptr);