netdev - [3/6] vxge: improve tx performance by using mmiowb() instead of wmb()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20090804202121.GD9924@neterion.com>
Date:	Tue, 4 Aug 2009 16:21:21 -0400
From:	Benjamin LaHaise <ben.lahaise@...erion.com>
To:	netdev@...r.kernel.org
Subject: [3/6] vxge: improve tx performance by using mmiowb() instead of
	wmb()

wmb() is extremely heavy on x86.  The semantics required in the driver are 
provided by mmiowb(), so use that and improve tx performance on P4 Xeons by 
5-10%.

Signed-off-by: Benjamin LaHaise <ben.lahaise@...erion.com>
Signed-off-by: Sreenivasa Honnur <sreenivasa.honnur@...erion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@...erion.com>
---
diff --git a/drivers/net/vxge/vxge-traffic.c b/drivers/net/vxge/vxge-traffic.c
index 370f55c..0efb769 100644
--- a/drivers/net/vxge/vxge-traffic.c
+++ b/drivers/net/vxge/vxge-traffic.c
@@ -1070,11 +1070,11 @@ static void __vxge_hw_non_offload_db_post(struct __vxge_hw_fifo *fifo,
 		VXGE_HW_NODBW_GET_NO_SNOOP(no_snoop),
 		&fifo->nofl_db->control_0);
 
-	wmb();
+	mmiowb();
 
 	writeq(txdl_ptr, &fifo->nofl_db->txdl_ptr);
-	wmb();
 
+	mmiowb();
 }
 
 /**
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html