On Tuesday 16 August 2005 16:03, Alan Cox wrote: > On Maw, 2005-08-16 at 15:19 +0200, Kern Sibbald wrote: > > have written, nor does it write() anything. When my read() is issued, I > > expect it to block, but it immediately returns with -1 and errno set to > > EAGAIN. If the read() is re-issued, a CPU intensive loop results as long > > as the other end does not read() the data written to the socket. This is > > a multi-threaded program, but the other threads are all blocked on > > something. > > You are describing behaviour as expected with nonblocking set. That > suggests to me that something or someone set or inherited the nonblock > flag on that socket.
I verified that I have not explicitly set nonblocking on the socket, so expect it to be default blocking. > Is the strange behaviour specific to the latest kernel ? This behavior, manifesting itself as a CPU loop, has been plaguing me for a number of months now. It is not specific to the latest kernel since it happened on FC3 and all kernels between. Before FC3 I was on RHEL3 (2.4 kernel) but am unsure if I saw the problem there, my best guess is that it is 2.6 related, but I cannot guarantee that. I have a workaround for the problem (sleep 200ms), but can repeat it and will be happy to provide more info as you request. The only thing I would correct in what I initially wrote is I believe that the other end of the socket did read some of the data I wrote before I did my read() expecting it to block. Kern - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/