On Tue, Jun 16, 2015 at 9:33 AM, Jonathan Morton <[email protected]> wrote: > >> On 16 Jun, 2015, at 19:18, Steinar H. Gunderson <[email protected]> >> wrote: >> >> On Tue, Jun 16, 2015 at 09:11:08AM -0700, Dave Taht wrote: >>> I just tossed off a quick patch for rsync, not that I have a clue as >>> to whether it would make any difference there. >> >> For bulk applications (like rsync), how would this make sense at all? >> I thought the entire point of this option was if you knew what data to send >> now, but that you might want to change your mind later if it takes some time >> to send it. The latter doesn't apply to rsync. > > Actually, it does. Rsync is designed to be used to update an existing set of > files, so the protocol interleaves control and data information > asynchronously. > > More generally, I think it’s worth setting LOWAT on *any* application that > uses select() or poll() with a readable and writable socket population > simultaneously.
Take samba as another potential example. I commonly see this increasing the SO_SNDBUF to a given value, but I am not sure if this is the right thing anymore. As samba is commonly used for filesharing (and things that take locks and do database-y stuff), improving interactivity might be a big win. Seeing the 50%! decrease in kernel memory on the original tests of TCP_SENT_LOWAT is very exciting in the context of those running samba on tiny tiny nas devices common in my world. And seeing apple enable it universally points to perhaps exploring the effects of just enabling it universally in linux (or in certain kinds of linux-based devices) at a "reasonable" value, for whatever value of reasonable exists. > - Jonathan Morton > > _______________________________________________ > Bloat mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/bloat -- Dave Täht What will it take to vastly improve wifi for everyone? https://plus.google.com/u/0/explore/makewififast _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
