From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] printk: Warn about dropped messages also on extended consoles Date: Thu, 30 Jul 2015 09:39:01 -0400 Message-ID: <20150730133901.GC3504@mtj.duckdns.org> References: <1438255732-31326-1-git-send-email-pmladek@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: akpm@linux-foundation.org, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Petr Mladek Return-path: Content-Disposition: inline In-Reply-To: <1438255732-31326-1-git-send-email-pmladek@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello, On Thu, Jul 30, 2015 at 01:28:52PM +0200, Petr Mladek wrote: > The commit #6fe29354befe4c ("printk: implement support for extended console > drivers") added an extra buffer to format messages for extended consoles. > We need to put there also the warning about dropped messages, so it appears > on these consoles. I don't get it. Extended messages are all stamped with sequence number and the gap in sequence number is a clear sign of missing messages. > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index cf8c24203368..77d3d3698283 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -2254,8 +2254,15 @@ again: > } > > if (console_seq < log_first_seq) { > - len = sprintf(text, "** %u printk messages dropped ** ", > - (unsigned)(log_first_seq - console_seq)); > + static const char dropped_msg[] = > + "** %u printk messages dropped ** "; > + unsigned int dropped_count = > + (unsigned int)(log_first_seq - console_seq); > + > + len = sprintf(text, dropped_msg, dropped_count); > + if (nr_ext_console_drivers) > + ext_len = sprintf(ext_text, dropped_msg, > + dropped_count); And you can't shove random message in front of the header. Nacked-by: Tejun Heo Thanks. -- tejun