From:   "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To:     LKML <linux-kernel@vger.kernel.org>, RCU <rcu@vger.kernel.org>,
        "Paul E . McKenney" <paulmck@kernel.org>
Cc:     Michal Hocko <mhocko@suse.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Daniel Axtens <dja@axtens.net>,
        Frederic Weisbecker <frederic@kernel.org>,
        Neeraj Upadhyay <neeraju@codeaurora.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Theodore Y . Ts'o" <tytso@mit.edu>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Uladzislau Rezki <urezki@gmail.com>,
        Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH 5/9] x86/mm: Switch to kvfree_rcu() API
Date:   Wed, 24 Nov 2021 12:03:04 +0100
Message-Id: <20211124110308.2053-6-urezki@gmail.com>
In-Reply-To: <20211124110308.2053-1-urezki@gmail.com>
References: <20211124110308.2053-1-urezki@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 arch/x86/mm/mmio-mod.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index 933a2ebad471..e75137a06c32 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -307,10 +307,8 @@ static void iounmap_trace_core(volatile void __iomem *addr)
 
 not_enabled:
 	spin_unlock_irq(&trace_lock);
-	if (found_trace) {
-		synchronize_rcu(); /* unregister_kmmio_probe() requirement */
-		kfree(found_trace);
-	}
+	if (found_trace)
+		kvfree_rcu(found_trace); /* unregister_kmmio_probe() requirement */
 }
 
 void mmiotrace_iounmap(volatile void __iomem *addr)
-- 
2.30.2