linux-kernel - Re: IRQ off latency of printk is very high

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 26 Oct 2007 15:28:31 -0500
From:	Matt Mackall <mpm@...enic.com>
To:	Benny Amorsen <benny+usenet@...rsen.dk>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: IRQ off latency of printk is very high

On Fri, Oct 26, 2007 at 02:57:18PM +0200, Benny Amorsen wrote:
> >>>>> "MM" == Matt Mackall <mpm@...enic.com> writes:
> 
> MM> Well there are things we can do, yes, but I'd be worried that
> MM> they've give up the deterministic behavior we rely on quite
> MM> heavily for debugging. If event A happens before event B, we must
> MM> see the message from A before the one from B, even if B happens in
> MM> irq context.
> 
> MM> And if event B is a hard lock up, we'd also like to be sure the
> MM> message for A actually gets out. If B happens in the interrupt
> MM> that comes in when we re-enable them, that won't happen.
> 
> I can see the concerns, but right now it all leads to disabling serial
> console for real-time servers. That is even less helpful for
> debugging.

That's not clear. No data is often better than false or misleading
data.

-- 
Mathematics is the supreme nostalgia of our time.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/