On Mon, Mar 11, 2013 at 12:51:44PM -0600, Tim Gardner wrote: > On 03/11/2013 12:14 PM, J. Bruce Fields wrote: > <snip> > >> > >> v2 - Move the array of 'struct ib_phys_buf' objects into struct rpcrdma_req > >> and pass this request down through rpcrdma_register_external() and > >> rpcrdma_register_default_external(). This is less overhead then using > >> kmalloc() and requires no extra error checking as the allocation burden is > >> shifted to the transport client. > > > > Oh good--so that works, and the req is the right place to put this? How > > are you testing this? > > > > (Just want to make it clear: I'm *not* an expert on the rdma code, so my > > suggestion to put this in the rpcrdma_req was a suggestion for something > > to look into, not a claim that it's correct.) > > > > Just compile tested so far. Incidentally, I've been through the call stack: > > call_transmit > xprt_transmit > xprt->ops->send_request(task) > xprt_rdma_send_request > rpcrdma_marshal_req > rpcrdma_create_chunks > rpcrdma_register_external > rpcrdma_register_default_external > > It appears that the context for kmalloc() should be fine unless there is > a spinlock held around call_transmit() (which seems unlikely). Right, though I think it shouldn't be GFP_KERNEL--looks like writes could wait on it. In any case, the embedding-in-rpcrdma_req solution does look cleaner if that's correct (e.g. if we can be sure there won't be two simultaneous users of that array). --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
