Jeff King <peff@xxxxxxxx> writes: > On Tue, Sep 22, 2015 at 12:45:51PM -0700, Junio C Hamano wrote: > >> One caveat is that the caller may not know in the first place. >> >> The last time I checked the existing callers of xread(), there were >> a few that read from a file descriptor they did not open themselves >> (e.g. unpack-objects that read from standard input). The invoker of >> these processes is free to do O_NONBLOCK their input stream for >> whatever reason. > > Yeah. I do not think this is a bug at all; the user might have their > reasons for handing off an O_NONBLOCK pipe. If we take xread() to mean > "try to read from fd until we get a real error, some data, or an EOF", > then it is perfectly reasonable to replace spinning on read() (which we > do now) with a poll() for efficiency. The caller (and the user) does not > have to care, and should not notice; the outcome will be the same. I think we are in agreement, and that answers the question/guidance Stefan asked earlier in $gmane/278414, which was: > So rather a combination of both, with the warning only spewing every > 5 seconds or such? and the answer obviously is "No warning, do a poll() without timeout to block". -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html