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| author | Dexuan Cui <decui@microsoft.com> | 2018-09-17 04:14:54 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-30 08:49:55 -0700 |
| commit | 41e270f6898e7502be9fd6920ee0a108ca259d36 (patch) | |
| tree | f74679a9255c3b509d8c6cf1e400f772e4ff5a48 | |
| parent | 17b57b1883c1285f3d0dc2266e8f79286a7bef38 (diff) | |
| download | linux-41e270f6898e7502be9fd6920ee0a108ca259d36.tar.gz linux-41e270f6898e7502be9fd6920ee0a108ca259d36.tar.bz2 linux-41e270f6898e7502be9fd6920ee0a108ca259d36.zip | |
Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()
With CONFIG_DEBUG_PREEMPT=y, I always see this warning:
BUG: using smp_processor_id() in preemptible [00000000]
Fix the false warning by using get/put_cpu().
Here vmbus_connect() sends a message to the host and waits for the
host's response. The host will deliver the response message and an
interrupt on CPU msg->target_vcpu, and later the interrupt handler
will wake up vmbus_connect(). vmbus_connect() doesn't really have
to run on the same cpu as CPU msg->target_vcpu, so it's safe to
call put_cpu() just here.
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hv/connection.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index ced041899456..f4d08c8ac7f8 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -76,6 +76,7 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, __u32 version) { int ret = 0; + unsigned int cur_cpu; struct vmbus_channel_initiate_contact *msg; unsigned long flags; @@ -118,9 +119,10 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, * the CPU attempting to connect may not be CPU 0. */ if (version >= VERSION_WIN8_1) { - msg->target_vcpu = - hv_cpu_number_to_vp_number(smp_processor_id()); - vmbus_connection.connect_cpu = smp_processor_id(); + cur_cpu = get_cpu(); + msg->target_vcpu = hv_cpu_number_to_vp_number(cur_cpu); + vmbus_connection.connect_cpu = cur_cpu; + put_cpu(); } else { msg->target_vcpu = 0; vmbus_connection.connect_cpu = 0; |