Messages in this thread Patch in this message | | | From | Dexuan Cui <> | Subject | [PATCH] Drivers: hv: vmbus: Use raw_smp_processor_id() in vmbus_connect() | Date | Thu, 23 Aug 2018 20:30:47 +0000 |
| |
With CONFIG_DEBUG_PREEMPT=y, I always see this warning: BUG: using smp_processor_id() in preemptible [00000000]
Fix the false warning by using raw_smp_processor_id().
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 use raw_smp_processor_id() 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> --- drivers/hv/connection.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index ced0418..c3b7040 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -119,8 +119,8 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, */ if (version >= VERSION_WIN8_1) { msg->target_vcpu = - hv_cpu_number_to_vp_number(smp_processor_id()); - vmbus_connection.connect_cpu = smp_processor_id(); + hv_cpu_number_to_vp_number(raw_smp_processor_id()); + vmbus_connection.connect_cpu = raw_smp_processor_id(); } else { msg->target_vcpu = 0; vmbus_connection.connect_cpu = 0; -- 2.7.4
| |