On Sat, 20 Nov 2021 11:19:13 -0600, Scott Cheloha wrote: > > One advantage to using stdio is that > > it will use the optimal I/O blocksize automatically so you could > > try using that instead of write(2) and see how it performs. > > tee(1) needs to write input to N drains, N >= 1. If we use stdio that > means we're doing N additional userspace copies, no?
Yes, that is true. Right now tee(1) doesn't check for partial writes which I suppose might happen with a larger buffer. In practice, as long as it is less than MAXPHYS it should be OK. > > > I thought MAXBSIZE was that constant, because we use it elsewhere, > > > e.g. in cat(1) and wc(1), but if not then what is the right thing? > > > Is it BUFSIZ? > > > > BUFSIZ is only 1K on OpenBSD, which is its own problem. > > That seems a bit small... hmmm... Yeah, BUFSIZ on Linux is 8K. I think most others are still 1K. - todd
