From: Ingo Molnar <mingo@elte.hu>
To: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>,
David Rientjes <rientjes@google.com>,
Jack Steiner <steiner@sgi.com>, Robin Holt <holt@sgi.com>,
Len Brown <len.brown@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
Yinghai Lu <yhlu.kernel@gmail.com>,
linux-acpi@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 1/4] printk: Allocate kernel log buffer earlier
Date: Tue, 1 Mar 2011 08:35:33 +0100 [thread overview]
Message-ID: <20110301073533.GA12384@elte.hu> (raw)
In-Reply-To: <4D6BF6CC.4000407@sgi.com>
* Mike Travis <travis@sgi.com> wrote:
> Ingo Molnar wrote:
> >* Yinghai Lu <yinghai@kernel.org> wrote:
> >
> >>+ pr_info("log_buf_len: %d\n", log_buf_len);
> >>+ pr_info("early log buf free: %d(%d%%)\n",
> >>+ free, (free * 100) / __LOG_BUF_LEN);
> >
> > Such debug printks should be removed from the final version of the patch ...
>
> Because I haven't been able to test on a fully configured
> system, this might be crucial info to figure out how to
> fix this when it happens on a customer system. Are you
> saying this small line is any less important than the
> other thousands and thousands of seemingly meaningless
> lines?
I think you are thinking about this the wrong way.
The real fix is to never even have to think about 'how much early buffer space do we
have left'. I.e. via the memblock allocation the buffer can be enlargened before the
big printks happen.
btw., a sidenote, it would make sense to record cases when we 'lose' printk output,
in the printk buffer itself. (it can be done by reserving a bit and updating the
'lost this many bytes' portion of the buffer, or so.)
Thanks,
Ingo
next prev parent reply other threads:[~2011-03-01 7:35 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-25 18:06 [PATCH 0/4] init: Shrink early messages to prevent overflowing the kernel log buffer Mike Travis
2011-02-25 18:06 ` [PATCH 1/4] printk: Allocate kernel log buffer earlier Mike Travis
2011-02-27 12:09 ` Ingo Molnar
2011-02-27 12:15 ` Ingo Molnar
2011-02-28 1:34 ` Yinghai Lu
2011-02-28 8:01 ` Ingo Molnar
2011-02-28 19:26 ` Mike Travis
2011-03-01 7:35 ` Ingo Molnar [this message]
2011-02-28 8:06 ` Ingo Molnar
2011-02-28 19:18 ` Yinghai Lu
2011-02-28 19:29 ` Mike Travis
2011-02-28 19:23 ` Mike Travis
2011-02-28 19:46 ` Yinghai Lu
2011-02-28 20:02 ` Mike Travis
2011-02-28 22:59 ` Yinghai Lu
2011-03-31 0:41 ` [PATCH 1/2] memblock: add error return when CONFIG_HAVE_MEMBLOCK is not set Mike Travis
2011-03-31 1:40 ` Yinghai Lu
2011-03-31 15:23 ` Mike Travis
2011-03-31 16:17 ` Yinghai Lu
2011-04-07 19:43 ` Mike Travis
2011-04-08 6:40 ` Ingo Molnar
2011-03-01 7:42 ` [PATCH 1/4] printk: Allocate kernel log buffer earlier Ingo Molnar
2011-02-28 19:14 ` Mike Travis
2011-02-25 18:06 ` [PATCH 2/4] printk: Break out printk_time Mike Travis
2011-02-27 11:56 ` Ingo Molnar
2011-02-25 18:06 ` [PATCH 3/4] printk: Minimize time zero output Mike Travis
2011-02-25 18:06 ` [PATCH 4/4] x86: Minimize SRAT messages Mike Travis
2011-02-27 12:03 ` Ingo Molnar
2011-02-28 19:41 ` Mike Travis
2011-03-01 7:51 ` Ingo Molnar
2011-03-31 2:38 ` Len Brown
2011-03-31 4:40 ` Yinghai Lu
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