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From: "Jörn Engel" <joern@logfs.org>
To: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"Koskinen Aaro (Nokia-D/Helsinki)" <aaro.koskinen@nokia.com>,
	Ingo Molnar <mingo@elte.hu>,
	David Woodhouse <dwmw2@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH/RFC v5 4/5]: core: Add dump device to call on oopses and panics
Date: Mon, 30 Nov 2009 10:35:41 +0100	[thread overview]
Message-ID: <20091130093541.GA14254@logfs.org> (raw)
In-Reply-To: <1259571118.7518.56.camel@localhost>

On Mon, 30 November 2009 10:51:58 +0200, Artem Bityutskiy wrote:
> 
> How about this patch on top of the existing one (untested):
> 
> +	/*
> +	 * Have we ever rotated around the circular buffer? If we never did,
> +	 * we have to have zeroes at the end.
> +	 */
> +	if (log_buf[end]) {
> +		s1 = log_buf + end;
> +		l1 = log_buf_len - end;
> +	} else {
> +		s1 = "";
> +		l1 = 0;

So now you are assuming that a) the buffer is initially zeroed and b)
noone ever writes NUL to it.  Is that correct?

I'm not sure whether those assumptions are valid.  If they are, then
this will obviously work.  Otherwise we can just always assume the
wrapped case.

Jörn

-- 
Write programs that do one thing and do it well. Write programs to work
together. Write programs to handle text streams, because that is a
universal interface.
-- Doug MacIlroy

  reply	other threads:[~2009-11-30  9:35 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-11  6:10 [PATCH] panic.c: export panic_on_oops Artem Bityutskiy
2009-10-12 11:15 ` Ingo Molnar
2009-10-12 11:23   ` Simon Kagstrom
2009-10-12 11:25   ` Artem Bityutskiy
2009-10-12 11:37     ` Ingo Molnar
2009-10-12 12:01       ` Simon Kagstrom
2009-10-12 12:09         ` Ingo Molnar
2009-10-12 12:15           ` David Woodhouse
2009-10-12 12:20             ` Ingo Molnar
2009-10-12 12:33               ` David Woodhouse
2009-10-12 12:36                 ` Ingo Molnar
2009-10-12 12:48                   ` David Woodhouse
2009-10-12 13:06               ` Simon Kagstrom
2009-10-12 13:15                 ` Ingo Molnar
2009-10-12 13:39                   ` Simon Kagstrom
2009-10-12 14:30                     ` Ingo Molnar
2009-10-12 15:01                       ` Simon Kagstrom
2009-10-12 15:23                         ` Ingo Molnar
2009-10-12 15:36                     ` Linus Torvalds
2009-10-12 15:44                       ` Linus Torvalds
2009-10-12 17:29                         ` Artem Bityutskiy
2009-10-12 17:43                           ` Linus Torvalds
2009-10-12 17:46                             ` Linus Torvalds
2009-10-12 18:09                       ` Andrew Morton
2009-10-12 18:23                         ` Ingo Molnar
2009-10-12 18:36                           ` Andrew Morton
2009-10-12 18:45                           ` Linus Torvalds
2009-10-12 19:14                             ` Ingo Molnar
2009-10-12 19:18                             ` Dirk Hohndel
2009-10-13  7:58                             ` Simon Kagstrom
2009-10-13  8:57                               ` Artem Bityutskiy
2009-10-13 13:17                             ` [PATCH/RFC v5 0/5]: mtdoops: fixes and improvements Simon Kagstrom
2009-10-13 13:21                               ` [PATCH/RFC v5 1/5]: mtdoops: avoid erasing already empty areas Simon Kagstrom
2009-10-13 13:22                               ` [PATCH/RFC v5 2/5]: mtdoops: Keep track of used/unused mtdoops pages in an array Simon Kagstrom
2009-10-13 13:22                               ` [PATCH/RFC v5 3/5]: mtdoops: Make page (record) size configurable Simon Kagstrom
2009-10-13 13:22                               ` [PATCH/RFC v5 4/5]: core: Add dump device to call on oopses and panics Simon Kagstrom
2009-10-13 15:37                                 ` Linus Torvalds
2009-11-26  9:36                                 ` Jörn Engel
2009-11-30  7:27                                   ` Artem Bityutskiy
2009-11-30  7:46                                     ` Jörn Engel
2009-11-30  8:51                                       ` Artem Bityutskiy
2009-11-30  9:35                                         ` Jörn Engel [this message]
2009-11-30  9:40                                           ` Artem Bityutskiy
2009-11-30  9:53                                             ` Simon Kagstrom
2009-11-30  9:54                                             ` Jörn Engel
2009-11-30 10:23                                         ` David Woodhouse
2009-11-30 10:27                                           ` David Woodhouse
2009-11-30  9:09                                   ` Artem Bityutskiy
2009-11-30  9:28                                     ` Simon Kagstrom
2009-10-13 13:22                               ` [PATCH/RFC v5 5/5]: mtdoops: refactor as a dump_device Simon Kagstrom
2009-10-14 13:34                             ` [PATCH v6 0/5]: mtdoops: fixes and improvements Simon Kagstrom
2009-10-14 13:40                               ` [PATCH v6 1/5]: mtdoops: avoid erasing already empty areas Simon Kagstrom
2009-10-14 13:41                               ` [PATCH v6 2/5]: mtdoops: Keep track of used/unused mtdoops pages in an array Simon Kagstrom
2009-10-14 13:41                               ` [PATCH v6 3/5]: mtdoops: Make page (record) size configurable Simon Kagstrom
2009-10-14 13:41                               ` [PATCH v6 4/5]: core: Add kernel message dumper to call on oopses and panics Simon Kagstrom
2009-10-14 16:49                                 ` Linus Torvalds
2009-10-14 13:41                               ` [PATCH v6 5/5]: mtdoops: refactor as a kmsg_dumper Simon Kagstrom
2009-10-14 15:12                                 ` Simon Kagstrom
2009-10-15  5:11                                   ` vimal singh
2009-10-12 12:27           ` [PATCH] panic.c: export panic_on_oops Simon Kagstrom
2009-10-12 12:32             ` Ingo Molnar
2009-10-12 13:08               ` Alan Cox
2009-10-12 13:25                 ` Ingo Molnar
2009-10-12 13:32                   ` David Woodhouse
2009-10-12 14:26                     ` Ingo Molnar
2009-10-12 14:36                       ` David Woodhouse
2009-10-12 15:14                         ` Ingo Molnar
2009-10-12 18:32                           ` Carl-Daniel Hailfinger
2009-10-12 19:18                             ` Ingo Molnar
2009-10-12 14:12       ` Arjan van de Ven

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