Computing apparatus includes a central processing unit (CPU), including at least one core and a cache in physical proximity to the at least one core, with a system memory and a bus connecting the CPU to the memory. A peripheral device is connected to the bus and is configured to write data items via the bus to a buffer in the system memory and to write respective completion reports to the system memory upon writing the data items to the buffer. The peripheral device is configured to detect that the CPU has read a first completion report from the system memory and then read context metadata associated with the first completion report from a given address in the system memory, and is further configured, upon writing a second completion report subsequent to the first completion report and associated with the same context metadata, to stash the second completion report and the context metadata from the given address to the cache.