Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2

[Stefan Metzmacher]

Hi David,

> > > So sendfile() as a concept (whether you use combinations of splice()
> > > system calls or the sendfile system call itsefl) isn't necessarily
> > > only about the zero-copy, it's really also about avoiding the user
> > > space memory management.
> >
> > I don't think so. Ok, maybe for webservers just serving tiny
> > html files, that's true. But for me with Samba it's really the
> > copy_to/from_iter() that is the major factor.
>
> Is that copy also doing the ip checksum?

Not in my tests. I guess there's offload in the network hardware
for this.

At least at the syscall layer of sendmsg() there's no checksuming
happening.

metze