Event Driven Remote Direct Memory Access Snapshots

A computer program product comprising a non-transitory computer readable medium having a computer readable program stored therein, wherein the computer readable program, when executed on a data processing system, causes the data processing system to:

• receive from an Input/Output (IO) adapter associated with the data processing system, an error event notification;
• store, in response to the error event notification, a snapshot of a RDMA resource associated with the error event notification;
• tear down the RDMA resource in response to the error event notification;
• and
• free memory associated with the RDMA resource in response to tearing down the RDMA resource, wherein the snapshot stores contents of the RDMA resource, wherein:
• the snapshot is stored in kernelspace in a flight recorder data structure of an IO adapter device driver corresponding to the IO adapter,
• storing the snapshot comprises, performing a lookup operation in a mapping data structure of cross memory map information corresponding to the resource identifier, invoking a cross memory map (xmap) service of a kernel to perform a cross memory read of the userspace RDMA resource, and performing a write of the contents of the userspace RDMA resource into an entry in the flight recorder data structure, and
• the error event notification comprises a resource identifier of a resource associated with an error event detected by the IO adapter.

A data processing system, comprising:

• a processor executing a kernel in a kernelspace and an application in a userspace;
• and
• an Input/Output adapter coupled to the processor, wherein the processor is configured to:
• receive from the Input/Output (IO) adapter an error event notification;
• store, in response to the error event notification, a snapshot of a RDMA resource associated with the error event notification in a kernelspace flight recorder data structure associated with a kernelspace resident IO adapter device driver;
• tear down the RDMA resource in response to the error event notification;
• and
• free memory associated with the RDMA resource in response to tearing down the RDMA resource, wherein the snapshot stores contents of the RDMA resource, wherein:
• the snapshot is stored in kernelspace in a flight recorder data structure of an IO adapter device driver corresponding to the IO adapter,
• the processor is configured to store the snapshot at least by performing a lookup operation in a mapping data structure of cross memory map information corresponding to the resource identifier, invoking a cross memory map (xmap) service of a kernel to perform a cross memory read of the userspace RDMA resource, and performing a write of the contents of the userspace RDMA resource into an entry in the flight recorder data structure, and
• the error event notification comprises a resource identifier of a resource associated with an error event detected by the IO adapter.