Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1253813

Re: [PATCH] printk: Don't discard earlier unprinted messages to make space

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On Thu, 2015-10-22 at 14:19 +0100, David Howells wrote:
> Petr Mladek <pmladek@suse.com> wrote:
> 
> > I would expect that the first few messages are printed to the console
> > before the buffer is wrapped. IMHO, in many cases, you are interested
> > into the final messages that describe why the system went down.
> 
> The last message might tell you that the machine panicked because the NMI
> handler triggered due to a spinlocked section taking too long or something.
> This doesn't help if the oops that caused the spinlock to remain held or
> whatever gets discarded from the buffer due to several intervening complaints
> that result secondarily from the initial oops.
> 
> > If there is no time to print them, you want to have them in the crash dump
> > (ring buffer) at least.
> 
> But not at the expense of discarding the first oops report.  *That* one is the
> most important.
> 
> Perhaps things could be arranged such that messages *can* be discarded from
> the front of the buffer *provided* they are not oops messages.

Of course, all this is a symptom of the fact that printk is now lossy.
If you had an option to make it reliable again, you wouldn't need to
argue over *which* messages to lose.

-- 
dwmw2

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] printk: Don't discard earlier unprinted messages to make  space David Howells <dhowells@redhat.com> - 2015-10-22 12:20 +0200
  Re: [PATCH] printk: Don't discard earlier unprinted messages to  make space David Woodhouse <dwmw2@infradead.org> - 2015-10-22 12:30 +0200
    Re: [PATCH] printk: Don't discard earlier unprinted messages to make  space Jan Kara <jack@suse.cz> - 2015-10-22 14:20 +0200
      Re: [PATCH] printk: Don't discard earlier unprinted messages to  make space David Woodhouse <dwmw2@infradead.org> - 2015-10-22 14:40 +0200
  Re: [PATCH] printk: Don't discard earlier unprinted messages to make  space Petr Mladek <pmladek@suse.com> - 2015-10-22 14:40 +0200
    Re: [PATCH] printk: Don't discard earlier unprinted messages to make space David Howells <dhowells@redhat.com> - 2015-10-22 15:20 +0200
      Re: [PATCH] printk: Don't discard earlier unprinted messages to  make space David Woodhouse <dwmw2@infradead.org> - 2015-10-22 15:30 +0200
      Re: [PATCH] printk: Don't discard earlier unprinted messages to make  space Petr Mladek <pmladek@suse.com> - 2015-10-23 10:50 +0200

csiph-web