Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754836AbbBBDW2 (ORCPT ); Sun, 1 Feb 2015 22:22:28 -0500 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:37214 "EHLO p3plsmtps2ded03.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754655AbbBBDW1 (ORCPT ); Sun, 1 Feb 2015 22:22:27 -0500 x-originating-ip: 72.167.245.219 From: Dexuan Cui To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, kys@microsoft.com, vkuznets@redhat.com Cc: haiyangz@microsoft.com Subject: [PATCH v2 2/3] hv: vmbus_post_msg: retry the hypercall on some transient errors Date: Sun, 1 Feb 2015 20:36:03 -0800 Message-Id: <1422851763-2391-1-git-send-email-decui@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2475 Lines: 78 I got HV_STATUS_INVALID_CONNECTION_ID on Hyper-V 2008 R2 when keeping running "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils" in a Linux guest. Looks the host has some kind of throttling mechanism if some kinds of hypercalls are sent too frequently. Without the patch, the driver can occasionally fail to load. Also let's retry HV_STATUS_INSUFFICIENT_MEMORY, though we didn't get it before. Removed 'case -ENOMEM', since the hypervisor doesn't return this. CC: "K. Y. Srinivasan" Signed-off-by: Dexuan Cui --- v2: updated the subject and changelog on HV_STATUS_INVALID_CONNECTION_ID: ret = -EAGAIN; added HV_STATUS_INSUFFICIENT_MEMORY removed unreachable -ENOMEM changed the delay from 100ms to 1000ms arch/x86/include/uapi/asm/hyperv.h | 2 ++ drivers/hv/connection.c | 11 +++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h index 90c458e..ce6068d 100644 --- a/arch/x86/include/uapi/asm/hyperv.h +++ b/arch/x86/include/uapi/asm/hyperv.h @@ -225,6 +225,8 @@ #define HV_STATUS_INVALID_HYPERCALL_CODE 2 #define HV_STATUS_INVALID_HYPERCALL_INPUT 3 #define HV_STATUS_INVALID_ALIGNMENT 4 +#define HV_STATUS_INSUFFICIENT_MEMORY 11 +#define HV_STATUS_INVALID_CONNECTION_ID 18 #define HV_STATUS_INSUFFICIENT_BUFFERS 19 typedef struct _HV_REFERENCE_TSC_PAGE { diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index c4acd1c..af2388f 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -440,9 +440,16 @@ int vmbus_post_msg(void *buffer, size_t buflen) ret = hv_post_message(conn_id, 1, buffer, buflen); switch (ret) { + case HV_STATUS_INVALID_CONNECTION_ID: + /* + * We could get this if we send messages too + * frequently. + */ + ret = -EAGAIN; + break; + case HV_STATUS_INSUFFICIENT_MEMORY: case HV_STATUS_INSUFFICIENT_BUFFERS: ret = -ENOMEM; - case -ENOMEM: break; case HV_STATUS_SUCCESS: return ret; @@ -452,7 +459,7 @@ int vmbus_post_msg(void *buffer, size_t buflen) } retries++; - msleep(100); + msleep(1000); } return ret; } -- 1.9.1 -- 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/