On Wed, Jan 13, 2010 at 12:24 AM, Jason Gunthorpe <jguntho...@obsidianresearch.com> wrote: > I'd actually think that the decline caused by exhausting credit on > the initiator side is far worse than ib_post_recv.. If ib_post_recv > really is noticable then maybe just force loading the RQ after XX > unposted are outstanding.
The performance penalty of exhausting credit on the initiator side is indeed far worse than that of a single ib_post_recv() call at the target side. But in a realistic setup such credit exhaustion happens at a rate of about once an hour, while ib_post_recv() is called once for every request. It is easy to set up an SRP I/O test where ib_post_recv() is called more than 250.000 times per second. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
