From owner-svn-src-all@FreeBSD.ORG Tue Jun 3 11:34:40 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 86F301C9; Tue, 3 Jun 2014 11:34:40 +0000 (UTC) Received: from mail109.syd.optusnet.com.au (mail109.syd.optusnet.com.au [211.29.132.80]) by mx1.freebsd.org (Postfix) with ESMTP id 1D20A2E85; Tue, 3 Jun 2014 11:34:39 +0000 (UTC) Received: from c122-106-147-133.carlnfd1.nsw.optusnet.com.au (c122-106-147-133.carlnfd1.nsw.optusnet.com.au [122.106.147.133]) by mail109.syd.optusnet.com.au (Postfix) with ESMTPS id 3F9D2D63CDA; Tue, 3 Jun 2014 21:11:43 +1000 (EST) Date: Tue, 3 Jun 2014 21:11:37 +1000 (EST) From: Bruce Evans X-X-Sender: bde@besplex.bde.org To: John-Mark Gurney Subject: Re: svn commit: r266985 - head/sys/ddb In-Reply-To: <201406022350.s52NoJe1096873@svn.freebsd.org> Message-ID: <20140603193401.W1018@besplex.bde.org> References: <201406022350.s52NoJe1096873@svn.freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.1 cv=eojmkOZX c=1 sm=1 tr=0 a=7NqvjVvQucbO2RlWB8PEog==:117 a=PO7r1zJSAAAA:8 a=Mtxxv-QYS58A:10 a=kj9zAlcOel0A:10 a=JzwRw_2MAAAA:8 a=Vqz-XXCvPmqd0_mSjAgA:9 a=aDvwUABlz0NCpQcX:21 a=aw1NSLr4V71kp6Ql:21 a=CjuIK1q_8ugA:10 Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jun 2014 11:34:40 -0000 On Mon, 2 Jun 2014, John-Mark Gurney wrote: > Log: > handle longer commands so that lines don't overflow... people who added > commands forgot to check this... Please fix the sticky "." key on your keyboard. It keeps repeating spuriously. Also the shift key. The correct fix is to remove or rename the long commands. > Modified: head/sys/ddb/db_command.c > ============================================================================== > --- head/sys/ddb/db_command.c Mon Jun 2 22:58:00 2014 (r266984) > +++ head/sys/ddb/db_command.c Mon Jun 2 23:50:19 2014 (r266985) > @@ -321,8 +321,8 @@ db_cmd_list(table) > register struct command *cmd; > > LIST_FOREACH(cmd, table, next) { > - db_printf("%-12s", cmd->name); > - db_end_line(12); > + db_printf("%-16s", cmd->name); > + db_end_line(16); > } > } 12 is already too long. Who wants to type 11-15 character command names? It would be better to punish long command name[r]s using "%-11.11s " format (with complications to avoid the trailing space(s) in the last column). This punishment is not very severe since command names should be unique in the first character or 2. This is needed anyway, to avoid typing long command names. The command name parser supports this by matching the name typed with a possibly-longer name in the table. Expanding to 16 adds the following bugs: - reduction in the number of fields on an 80 column terminal from 6 or 7 to 4 or 5 (from 6 * 12 + 7 or 8 left over depending on auto-wrap to 4 * 16 + 15 or 16 left over) - different mishandling of autowrap. In -current, the handling seems to be to always waste the last 16 columns (previously only 8). This avoids problems with auto-wrap, but the change makes it waste many more columns. The number of fields is now 4 (was 6). 6 * 13 would fit just as well as 6 * 12 (except for terminals with between 73 and 78 columns). The formatting now works as follows: The db_end_line()'s are not correctly paired with the db_printf()'s, but they work. There is none before the first db_printf(), but callers should arrange to start on a new line so there is no danger of overruning the line before db_end_line() can check for overrun. Then each db_end_line() except the last one (dynamically) is correctly paired with the next db_printf(). Then the last db_end_line() checks for output that will never be done. It may print a newline prematurely. Perhaps an extra newline is printed to complete the table. This is unclear because db_cmd_list() doesn't print one itself. I think the prompt code _expects_ to be called with the previous line not always terminated, and prints a newline iff necessary. It used to give 7 fields of width 12 that were somehow usually displayed nicely in 80 columns on a syscons terminal, depending on whether the 12 characters printed in the 7 available columns for the last field had enough trailing spaces. The trailing spaces were apparently discarded by terminal magic on some terminals. But command names of length exactly 8 gave auto-wrap problems, and ones of length 9-12 were displayed in full and ran into the next line iff they were in the 7th field. Command names of length 12 of course ran into each other in any field except the last one. Since command namers usually get things like this wrong, short names should be enforced by panicing for long ones. I once fixed all sleep message strings to fit in the available 6 characters, but neglected to enforce this, so there are many more broken ones now. This bug is now most common in the zfs and audit subsystems. From top output: 10 root -16 - 0K 16K audit_ 21 12:47 0.00% [audit] 6 root -8 - 0K 96K spa->s 5 0:30 0.00% [zfskern{trim zfreefall}] 6 root 20 - 0K 96K arc_re 10 0:20 0.00% [zfskern{arc_reclaim_thre}] 23 root -16 - 0K 16K sdflus 18 0:19 0.00% [softdepflush] 6 root -8 - 0K 96K l2arc_ 14 0:13 0.00% [zfskern{l2arc_feed_threa}] 670 auditdistd 20 0 23692K 3292K sigwai 11 0:04 0.00% auditdistd: [audit.ysv.FreeBSD. 8 root -16 - 0K 16K ipmire 0 0:00 0.00% [ipmi0: kcs] The bad sleep messages are not even designed to be useful when truncated to 6 characters, so for example almost the signal in audit_mumble is truncated, but all the noise is kept. ipmire would be a good name for mired ip but not for ipmi. The bad sleep messages are mishandled differently in ps; - in normal ps l output, MWCHAN is 6 wide - but if any sleep message is longer than 6, MWCHAN is up to 8 wide. The above subsystems still get their strings truncated, e.g. (ps lH output): 0 6 0 0 20 0 0 96 arc_recl DL - 0:20.04 [zfsk 0 6 0 0 -8 0 0 96 l2arc_fe DL - 0:13.24 [zfsk 0 6 0 0 -8 0 0 96 spa->spa DL - 0:29.53 [zfsk 0 6 0 0 -8 0 0 96 tx->tx_q DL - 0:05.60 [zfsk 0 6 0 0 -8 0 0 96 tx->tx_s DL - 62:10.01 [zfsk 0 10 0 0 -16 0 0 16 audit_wo DL - 12:47.10 [audi 78 670 669 0 20 0 23692 3292 sigwait SJ - 0:03.56 audit Space that is not available is used to expand the MWCHAN field (and some others), so the main command name is truncated almost into oblivion (just 4 columns for it, after wasting another one for "["). - wide output format fixes the truncated main command name, but MWCHAN remains truncated at 8: 0 6 0 0 20 0 0 96 arc_recl DL - 0:20.04 [zfskern/arc_reclaim] 0 6 0 0 -8 0 0 96 l2arc_fe DL - 0:13.24 [zfskern/l2arc_feed_] 0 6 0 0 -8 0 0 96 spa->spa DL - 0:29.53 [zfskern/trim zfreef] 0 6 0 0 -8 0 0 96 tx->tx_q DL - 0:05.60 [zfskern/txg_thread_] 0 6 0 0 -8 0 0 96 tx->tx_s DL - 62:10.58 [zfskern/txg_thread_] 0 10 0 0 -16 0 0 16 audit_wo DL - 12:47.20 [audit] Actually, thread names are truncated by other mechanisms. Partly in the kernel, so ps cannot recover. Bruce