On Tue, Sep 26, 2023 at 12:21 PM Christian Brauner <brauner@xxxxxxxxxx> wrote: > Hm, so the thing that is worrysome about this change is that this may > cause regressions afaict as this is a pretty significant change from > current behavior. Would you prefer a new flag for explicitly selecting "wait until at least one byte was transferred, but don't wait further"? Because many applications need this behavior, and some (like nginx) have already worked around the problem by limiting the maximum transaction size, which I consider a bad workaround, because it leads to unnecessary system calls and still doesn't really solve the latency problem. On the other hand, what exactly would the absence of this flag mean... the old behavior, without my patch, can lead to partial transfers, and the absence of the flag doesn't mean it can't happen; my patch tackles just one corner case, but one that is important for me. We have been running this patch in production for nearly a year (and will continue to do so until upstream kernels have a proper solution) and never observed a problem, and I consider it safe, but I acknowledge the risk that this may reveal obscure application bugs if applied globally to all Linux kernels, so I understand your worries. Max
