A Multi-Packet receive WQ comes to improve performance and memory footprint. It is comprised of work requests that can be consumed by multiple packets. Buffers pointed by SGEs of each work request in a multi packet WQ are divided into strides. Both buffer size and stride size must be identical in all work requests of the same multi packet WQ and are set during WQ creation. A single WR in a Multi-Packet WQ can generate multiple completions, depends on the number of packets consumed. Each packet starts at the beginning of a stride and is written in stride granularity. Here is an example of a work request comprised of 3 strides. Packet 1 is larger than a stride so it occupies 2 strides. Packet 2 fits in a single stride. Each packet will generate its own completion. | | |[packet2]| | [packet1] | | |_________|_________|_________| stride stride stride <-- work request --> A Multi-Packet WQ reduces the number of needed post-recv operations thus increasing performance: In the example above, a single post-recv operation was performed instead of 2.
Looks like a nice feature, would be nice if we could use it... The problem is that adding a different logic in case this feature exists is messy and difficult. Is there any way we can come up with a verbs API that will utilize this feature but hide the implementation details from the ULPs? Maybe something that wraps post_recv? -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
