Peter Hurley writes: > On 09/27/2013 01:27 PM, Peter Hurley wrote: > > Commit f95499c3030fe1bfad57745f2db1959c5b43dca8, > > n_tty: Don't wait for buffer work in read() loop > > creates a race window which can cause a pty master read() > > to miss the last pty slave write(s) and return -EIO instead, > > thus signalling the pty slave is closed. This can happen when > > the pty slave is written and immediately closed but before the > > tty buffer i/o loop receives the new input; the pty master > > read() is scheduled, sees its read buffer is empty and the > > pty slave has been closed, and exits. > > > > Because tty_flush_to_ldisc() has significant performance impact > > for parallel i/o, rather than revert the commit, special case this > > condition (ie., when the read buffer is empty and the 'other' pty > > has been closed) and, only then, wait for buffer work to complete > > before re-testing if the read buffer is still empty. > > > > As before, subsequent pty master reads return any available data > > until no more data is available, and then returns -EIO to > > indicate the pty slave has closed. > > > > Reported-by: Mikael Pettersson <mikpeli...@gmail.com> > > Signed-off-by: Peter Hurley <pe...@hurleysoftware.com> > > I tested this patch with the gcc ada ACATS testsuite and got this > summary so all seems ok with this patch. > > === acats Summary === > # of expected passes 805 > # of unexpected failures 0 > > ... > > === acats Summary === > # of expected passes 772 > # of unexpected failures 0 > > ... > > === acats Summary === > # of expected passes 743 > # of unexpected failures 0 > > Mikael, > > I'd appreciate if you could re-test with this patch and > confirm the issue is fixed.
I did a big pile of gcc bootstrap + regression test runs today with this patch, and everything looks good. Thus: Tested-by: Mikael Pettersson <mikpeli...@gmail.com> Thanks, /Mikael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
