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From: Jon Mason <jon.mason@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Jiang <dave.jiang@intel.com>
Subject: [PATCH 08/10] NTB: memcpy lockup workaround
Date: Mon,  6 May 2013 18:55:27 -0700	[thread overview]
Message-ID: <1367891729-11738-9-git-send-email-jon.mason@intel.com> (raw)
In-Reply-To: <1367891729-11738-1-git-send-email-jon.mason@intel.com>

The system will appear to lockup for long periods of time due to the NTB
driver spending too much time in memcpy.  Avoid this by reducing the
number of packets that can be serviced on a given interrupt.

Signed-off-by: Jon Mason <jon.mason@intel.com>
---
 drivers/ntb/ntb_transport.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index cd9745b..583a7d3 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -1034,11 +1034,16 @@ out:
 static void ntb_transport_rx(unsigned long data)
 {
 	struct ntb_transport_qp *qp = (struct ntb_transport_qp *)data;
-	int rc;
+	int rc, i;
 
-	do {
+	/* Limit the number of packets processed in a single interrupt to
+	 * provide fairness to others
+	 */
+	for (i = 0; i < qp->rx_max_entry; i++) {
 		rc = ntb_process_rxc(qp);
-	} while (!rc);
+		if (rc)
+			break;
+	}
 }
 
 static void ntb_transport_rxc_db(void *data, int db_num)
-- 
1.7.9.5


  parent reply	other threads:[~2013-05-07  1:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-07  1:55 [PATCH 0/10] NTB: Bug Fixes Jon Mason
2013-05-07  1:55 ` [PATCH 01/10] NTB: variable dereferenced before check Jon Mason
2013-05-07  1:55 ` [PATCH 02/10] ntb: off by one sanity checks Jon Mason
2013-05-07  1:55 ` [PATCH 03/10] NTB: fix pointer math issues Jon Mason
2013-05-07  1:55 ` [PATCH 04/10] NTB: Handle 64bit BAR sizes Jon Mason
2013-05-07  1:55 ` [PATCH 05/10] NTB: Link toggle memory leak Jon Mason
2013-05-07  1:55 ` [PATCH 06/10] NTB: reset tx_index on link toggle Jon Mason
2013-05-07  1:55 ` [PATCH 07/10] NTB: Correctly handle receive buffers of the minimal size Jon Mason
2013-05-07  1:55 ` Jon Mason [this message]
2013-05-07  1:55 ` [PATCH 09/10] ntb_netdev: remove from list on exit Jon Mason
2013-05-07  1:55 ` [PATCH 10/10] NTB: Multiple NTB client fix Jon Mason

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