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From: Ohad Ben-Cohen <ohad@wizery.com>
To: linux-omap@vger.kernel.org
Cc: Kanigeri Hari <h-kanigeri2@ti.com>,
	Hiroshi Doyu <Hiroshi.DOYU@nokia.com>,
	Ohad Ben-Cohen <ohad@wizery.com>
Subject: [PATCH 1/4] omap: mailbox cleanup: convert rwlocks to spinlock
Date: Tue, 27 Apr 2010 20:56:19 +0300	[thread overview]
Message-ID: <1272390982-14882-2-git-send-email-ohad@wizery.com> (raw)
In-Reply-To: <1272390982-14882-1-git-send-email-ohad@wizery.com>

rwlocks are slower and have potential starvation issues so spinlocks are
generally preferred

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
---
 arch/arm/plat-omap/mailbox.c |   20 ++++++++++----------
 1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 08a2df7..d73d51a 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -31,7 +31,7 @@
 
 static struct workqueue_struct *mboxd;
 static struct omap_mbox *mboxes;
-static DEFINE_RWLOCK(mboxes_lock);
+static DEFINE_SPINLOCK(mboxes_lock);
 
 static int mbox_configured;
 
@@ -330,14 +330,14 @@ struct omap_mbox *omap_mbox_get(const char *name)
 	struct omap_mbox *mbox;
 	int ret;
 
-	read_lock(&mboxes_lock);
+	spin_lock(&mboxes_lock);
 	mbox = *(find_mboxes(name));
 	if (mbox == NULL) {
-		read_unlock(&mboxes_lock);
+		spin_unlock(&mboxes_lock);
 		return ERR_PTR(-ENOENT);
 	}
 
-	read_unlock(&mboxes_lock);
+	spin_unlock(&mboxes_lock);
 
 	ret = omap_mbox_startup(mbox);
 	if (ret)
@@ -363,15 +363,15 @@ int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
 	if (mbox->next)
 		return -EBUSY;
 
-	write_lock(&mboxes_lock);
+	spin_lock(&mboxes_lock);
 	tmp = find_mboxes(mbox->name);
 	if (*tmp) {
 		ret = -EBUSY;
-		write_unlock(&mboxes_lock);
+		spin_unlock(&mboxes_lock);
 		goto err_find;
 	}
 	*tmp = mbox;
-	write_unlock(&mboxes_lock);
+	spin_unlock(&mboxes_lock);
 
 	return 0;
 
@@ -384,18 +384,18 @@ int omap_mbox_unregister(struct omap_mbox *mbox)
 {
 	struct omap_mbox **tmp;
 
-	write_lock(&mboxes_lock);
+	spin_lock(&mboxes_lock);
 	tmp = &mboxes;
 	while (*tmp) {
 		if (mbox == *tmp) {
 			*tmp = mbox->next;
 			mbox->next = NULL;
-			write_unlock(&mboxes_lock);
+			spin_unlock(&mboxes_lock);
 			return 0;
 		}
 		tmp = &(*tmp)->next;
 	}
-	write_unlock(&mboxes_lock);
+	spin_unlock(&mboxes_lock);
 
 	return -EINVAL;
 }
-- 
1.6.3.3


  reply	other threads:[~2010-04-27 17:58 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-27 17:56 [PATCH 0/4] omap: mailbox: cleanup & simplify Ohad Ben-Cohen
2010-04-27 17:56 ` Ohad Ben-Cohen [this message]
2010-04-28  7:50   ` [PATCH 1/4] omap: mailbox cleanup: convert rwlocks to spinlock Hiroshi DOYU
2010-04-28 10:41     ` Ohad Ben-Cohen
2010-04-29 12:44   ` Kanigeri, Hari
2010-04-29 13:14     ` Ohad Ben-Cohen
2010-04-29 13:35       ` Ohad Ben-Cohen
2010-04-27 17:56 ` [PATCH 2/4] omap: mailbox cleanup: split MODULE_AUTHOR line Ohad Ben-Cohen
2010-04-27 17:56 ` [PATCH 3/4] omap: mailbox: fix reverse likeliness Ohad Ben-Cohen
2010-04-27 17:56 ` [PATCH 4/4] omap: mailbox: convert block api to kfifo Ohad Ben-Cohen
2010-04-28  5:52   ` Hiroshi DOYU
2010-04-28 11:02     ` Ohad Ben-Cohen
2010-04-28 11:16       ` Hiroshi DOYU
2010-04-28 11:25         ` Ohad Ben-Cohen
2010-04-28 11:52           ` Hiroshi DOYU
2010-04-28 12:03             ` Ohad Ben-Cohen
2010-04-28  5:56   ` Hiroshi DOYU
2010-04-28 11:02     ` Ohad Ben-Cohen

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