From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: mgamal@redhat.com, Stephen Hemminger <stephen@networkplumber.org>,
Stephen Hemminger <sthemmin@microsoft.com>
Subject: [dpdk-dev] [PATCH v2 1/4] bus/vmbus: fix race in sub channel creation
Date: Wed, 5 Dec 2018 14:11:56 -0800 [thread overview]
Message-ID: <20181205221159.6336-1-stephen@networkplumber.org> (raw)
In-Reply-To: <1543575881.5400.33.camel@redhat.com>
When using multiple queues, there was a race with the kernel
in setting up the second channel. This regression is due to a kernel change
which does not allow accessing sysfs files for Hyper-V channels that are not opened.
The fix is simple, just move the logic to detect not ready
sub channels earlier in the existing loop.
Fixes: 831dba47bd36 ("bus/vmbus: add Hyper-V virtual bus support")
Reported-by:Mohammed Gamal <mgamal@redhat.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
drivers/bus/vmbus/linux/vmbus_uio.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c b/drivers/bus/vmbus/linux/vmbus_uio.c
index 12e97e3a420a..38df4d724ed5 100644
--- a/drivers/bus/vmbus/linux/vmbus_uio.c
+++ b/drivers/bus/vmbus/linux/vmbus_uio.c
@@ -357,6 +357,12 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
continue;
}
+ if (!vmbus_isnew_subchannel(primary, relid))
+ continue; /* Already know about you */
+
+ if (!vmbus_uio_ring_present(dev, relid))
+ continue; /* Ring may not be ready yet */
+
snprintf(subchan_path, sizeof(subchan_path), "%s/%lu",
chan_path, relid);
err = vmbus_uio_sysfs_read(subchan_path, "subchannel_id",
@@ -370,12 +376,6 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
if (subid == 0)
continue; /* skip primary channel */
- if (!vmbus_isnew_subchannel(primary, relid))
- continue;
-
- if (!vmbus_uio_ring_present(dev, relid))
- continue; /* Ring may not be ready yet */
-
err = vmbus_uio_sysfs_read(subchan_path, "monitor_id",
&monid, UINT8_MAX);
if (err) {
--
2.19.2
next prev parent reply other threads:[~2018-12-05 22:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 11:04 [dpdk-dev] Problems running netvsc multiq Mohammed Gamal
2018-11-30 18:27 ` Stephen Hemminger
2018-11-30 19:06 ` Mohammed Gamal
2018-12-04 16:48 ` Stephen Hemminger
2018-12-04 16:56 ` Mohammed Gamal
2018-12-05 22:12 ` Stephen Hemminger
2018-12-05 22:32 ` Stephen Hemminger
2018-12-07 11:15 ` Mohammed Gamal
2018-12-07 17:31 ` Stephen Hemminger
2018-12-07 19:18 ` Stephen Hemminger
2018-12-08 8:10 ` Mohammed Gamal
2018-11-30 20:24 ` [dpdk-dev] [PATCH] bus/vmbus: fix race in sub channel creation Stephen Hemminger
2018-12-03 6:02 ` Mohammed Gamal
2018-12-03 16:48 ` Stephen Hemminger
2018-12-04 11:59 ` Mohammed Gamal
2018-12-05 22:11 ` Stephen Hemminger [this message]
2018-12-05 22:11 ` [dpdk-dev] [PATCH v2 2/4] net/netvsc: enable SR-IOV Stephen Hemminger
2018-12-05 22:11 ` [dpdk-dev] [PATCH v2 3/4] net/netvsc: disable multi-queue on older servers Stephen Hemminger
2018-12-05 22:11 ` [dpdk-dev] [PATCH v2 4/4] bus/vmbus: debug subchannel setup Stephen Hemminger
2018-12-19 2:02 ` [dpdk-dev] [PATCH v2 1/4] bus/vmbus: fix race in sub channel creation Thomas Monjalon
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