On Wed, Dec 15, 2021 at 9:38 PM <rsbecker@xxxxxxxxxxxxx> wrote: > > The maximum I/O size on the platform is 56Kb. Anything larger will fail. That's why we use xread and xwrite for non-buffered I/O. That sounds like it's orthogonal to what this patch is changing. Regardless of this patch, the actual writes are performed by write_or_die, which calls write_in_full. In turn, write_in_full calls xwrite however often is necessary. We are not making any assumptions anywhere about how large individual write syscalls turn out. Git packets use userspace buffers so we can read and write them no matter what the underlying IO sizes are.