linux-kernel - [PATCH 5/9] x86/mm: Switch to kvfree

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Message-Id: <20211124110308.2053-6-urezki@gmail.com>
Date:   Wed, 24 Nov 2021 12:03:04 +0100
From:   "Uladzislau Rezki (Sony)" <urezki@...il.com>
To:     LKML <linux-kernel@...r.kernel.org>, RCU <rcu@...r.kernel.org>,
        "Paul E . McKenney" <paulmck@...nel.org>
Cc:     Michal Hocko <mhocko@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Daniel Axtens <dja@...ens.net>,
        Frederic Weisbecker <frederic@...nel.org>,
        Neeraj Upadhyay <neeraju@...eaurora.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Theodore Y . Ts'o" <tytso@....edu>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Uladzislau Rezki <urezki@...il.com>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...ymobile.com>,
        Steven Rostedt <rostedt@...dmis.org>
Subject: [PATCH 5/9] x86/mm: Switch to kvfree_rcu() API

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@...dmis.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@...il.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