Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758521Ab3ERCy2 (ORCPT ); Fri, 17 May 2013 22:54:28 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:54799 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753551Ab3ERCy0 (ORCPT ); Fri, 17 May 2013 22:54:26 -0400 From: Jonghwan Choi To: Jon Mason Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, Jonghwan Choi Subject: [PATCH 3.9-stable] NTB: memcpy lockup workaround Date: Sat, 18 May 2013 11:52:17 +0900 Message-Id: <1368845537-4250-1-git-send-email-jhbird.choi@samsung.com> X-Mailer: git-send-email 1.8.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1959 Lines: 59 From: Jon Mason This patch looks like it should be in the 3.9-stable tree, should we apply it? ------------------ From: "Jon Mason " commit c336acd3331dcc191a97dbc66a557d47741657c7 upstream 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. Cc: # 3.9.x: ad3e2751: ntb: off by one Cc: # 3.9.x: cc0f868d: NTB: fix pointer math Cc: # 3.9.x: 113fc505: NTB: Handle 64bit BAR Cc: # 3.9.x: b77b2637: NTB: Link toggle memory Cc: # 3.9.x: 90f9e934: NTB: reset tx_index on Cc: # 3.9.x: c9d534c8: NTB: Correctly handle receive Signed-off-by: Jon Mason Signed-off-by: Jonghwan Choi --- 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 a288a26..0f66daa 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) -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/