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From: Tejun Heo <tj@kernel.org>
To: davem@davemloft.net
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp,
	sd@queasysnail.net, Tejun Heo <tj@kernel.org>
Subject: [PATCH 1/4] netconsole: remove unnecessary netconsole_target_get/out() from write_msg()
Date: Mon, 11 May 2015 12:41:31 -0400	[thread overview]
Message-ID: <1431362494-9874-2-git-send-email-tj@kernel.org> (raw)
In-Reply-To: <1431362494-9874-1-git-send-email-tj@kernel.org>

write_msg() grabs target_list_lock and walks target_list invoking
netpool_send_udp() on each target.  Curiously, it protects each
iteration with netconsole_target_get/put() even though it never
releases target_list_lock which protects all the members.

While this doesn't harm anything, it doesn't serve any purpose either.
The items on the list can't go away while target_list_lock is held.
Remove the unnecessary get/put pair.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
---
 drivers/net/netconsole.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 15731d1..30c0524 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -744,7 +744,6 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
 
 	spin_lock_irqsave(&target_list_lock, flags);
 	list_for_each_entry(nt, &target_list, list) {
-		netconsole_target_get(nt);
 		if (nt->enabled && netif_running(nt->np.dev)) {
 			/*
 			 * We nest this inside the for-each-target loop above
@@ -760,7 +759,6 @@ static void write_msg(struct console *con, const char *msg, unsigned int len)
 				left -= frag;
 			}
 		}
-		netconsole_target_put(nt);
 	}
 	spin_unlock_irqrestore(&target_list_lock, flags);
 }
-- 
2.1.0


  reply	other threads:[~2015-05-11 16:41 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-11 16:41 [PATCHSET v3] netconsole: implement extended console support Tejun Heo
2015-05-11 16:41 ` Tejun Heo [this message]
2015-05-11 16:41 ` [PATCH 2/4] netconsole: make netconsole_target->enabled a bool Tejun Heo
2015-05-11 16:41 ` [PATCH 3/4] netconsole: make all dynamic netconsoles share a mutex Tejun Heo
2015-05-11 16:41 ` [PATCH 4/4] netconsole: implement extended console support Tejun Heo
2015-05-11 17:23   ` David Miller
2015-05-11 20:37     ` Tejun Heo
2015-05-12 23:23       ` David Miller
2015-05-13 15:46         ` Tejun Heo
2015-05-14  4:39           ` David Miller
2015-05-14 15:12             ` Tejun Heo
2015-05-12 23:36   ` Andrew Morton
2015-05-13  2:41     ` David Miller
2015-05-13 15:32     ` Tejun Heo

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