Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote: > That means I haven't seen the cover letter and do not have any > context for this proposed change. https://lore.kernel.org/linux-fsdevel/20230316152618.711970-1-dhowells@xxxxxxxxxx/ > We've tried combining the sendpages calls in here before. It > results in a significant and measurable performance regression. > See: > > da1661b93bf4 ("SUNRPC: Teach server to use xprt_sock_sendmsg for socket sends") The commit replaced the use of sendpage with sendmsg, but that took away the zerocopy aspect of sendpage. The idea behind MSG_SPLICE_PAGES is that it allows you to do keep that. I'll have to try reapplying this commit and adding the MSG_SPLICE_PAGES flag. > Therefore, this kind of change needs to be accompanied by both > benchmark results and some field testing to convince me it won't > cause harm. Yep. > And, we have to make certain that this doesn't break operation > with kTLS sockets... do they support MSG_SPLICE_PAGES ? I haven't yet tackled AF_TLS, AF_KCM or AF_SMC as they seem significantly more complex than TCP and UDP. I thought I'd get some feedback on what I have before I tried my hand at those. David
