From owner-freebsd-current@FreeBSD.ORG Sun Aug 2 13:22:36 2009 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E90AC106566C for ; Sun, 2 Aug 2009 13:22:36 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from ch-smtp01.sth.basefarm.net (ch-smtp01.sth.basefarm.net [80.76.149.212]) by mx1.freebsd.org (Postfix) with ESMTP id 78EAD8FC08 for ; Sun, 2 Aug 2009 13:22:36 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from c83-253-252-234.bredband.comhem.se ([83.253.252.234]:46385 helo=mx.exscape.org) by ch-smtp01.sth.basefarm.net with esmtp (Exim 4.68) (envelope-from ) id 1MXb0o-0004NQ-5Y; Sun, 02 Aug 2009 15:22:08 +0200 Received: from [192.168.1.5] (macbookpro [192.168.1.5]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mx.exscape.org (Postfix) with ESMTPSA id EEE12E04FC; Sun, 2 Aug 2009 15:21:48 +0200 (CEST) Message-Id: <4ACF3F62-44B9-4693-A1D3-8987848100C0@exscape.org> From: Thomas Backman To: Ed Schouten In-Reply-To: <20090802123108.GY1292@hoeg.nl> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v935.3) Date: Sun, 2 Aug 2009 15:21:46 +0200 References: <20090802105033.GG1884@deviant.kiev.zoral.com.ua> <20090802123108.GY1292@hoeg.nl> X-Mailer: Apple Mail (2.935.3) X-Originating-IP: 83.253.252.234 X-Scan-Result: No virus found in message 1MXb0o-0004NQ-5Y. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1MXb0o-0004NQ-5Y c3d2fa886760eb086441ecebfcbfc310 Cc: Kostik Belousov , FreeBSD Current Subject: Re: HEAD tty seems to drop characters X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Aug 2009 13:22:37 -0000 On Aug 2, 2009, at 14:31, Ed Schouten wrote: > Hi Kostik, > > * Kostik Belousov wrote: >> I run a screen(1), where I tried to copy large portion of output and >> paste it into vi. This resulted in the loss of the characters at >> random >> points inside the pasted text. > > I already took some time to investigate the issue. I have attached a > patch that should already improve the situation: > > - write() on a pseudo-terminal master also accounted the data that was > read into the kernel, but couldn't be passed to the TTY (which is > likely to happen in non-blocking mode). > > - There was also a small unrelated issue; input on a TTY which has > been > configured in block (bypass) mode wouldn't set the input high water > mark. > > For some reason, the data loss doesn't occur when SSHing to myself > multiple times, but still causes screen(1) to drop some bytes later > on. > > Even though it's always very easy to blame other applications, I > suspect > this may be because I reduced the input buffer size from 8 KB to 2 KB > per pseudo-terminal. Maybe screen(1) can't deal with this. To be > investigated... Hmm, so I'm guessing this is the reason I've had trouble with copying/ pasting backtraces the last few days (I ssh into the box, which runs screen). I have, AFAIK, not noticed anything else than newlines dropping, though (I usually end up with lines such as "zfs_suspend_fs() at zfs_suspend_fs+0x2bzfs_ioc_recv() at zfs_ioc_recv +0x28b"). Also, do you know when this issue first appeared? I think I've been experiening this for more than a week or so, probably a lot longer (2-4 weeks? even longer)... could be sketchy memory, though. Regards, Thomas