From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helge Deller Subject: Re: [PATCH] parisc: blink loadavg LEDs on Oops Date: Tue, 06 Jan 2009 16:40:14 +0100 Message-ID: <49637B5E.7010103@gmx.de> References: <49635B41.5060205@gmx.de> <7d01f9f00901060728w2001ed38v15c305d1472cb66@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Kyle McMartin , linux-parisc To: Thibaut VARENE Return-path: In-Reply-To: <7d01f9f00901060728w2001ed38v15c305d1472cb66@mail.gmail.com> List-ID: List-Id: linux-parisc.vger.kernel.org Thibaut VARENE wrote: > On Tue, Jan 6, 2009 at 2:23 PM, Helge Deller wrote: >> - blink loadavg LEDs only (not all LEDs) twice a second on Oops > > Just out of curiosity, why wouldn't you want to have all leds blinking > on something as serious as an Oops? I kind of liked to clearly see > when something went wrong... Yeah, valid question. While doing some bugfixing on the HIL drivers I noticed that suddenly all LEDs were lit on the 715/64. It was strange, as I still was using the machine and it was running fine. The reason why the LEDs were lit was, that oops_in_progress was set due a bug in my code. In dmesg I saw: BUG: rwlock cpu recursion on CPU#0, modprobe/1098, 00a1599c Backtrace: [<102a9c78>] _raw_write_lock+0x54/0x8c .... So, whenever the kernel hits such a WARNING(), all LEDs will blink. Now after my patch, the 4 LEDs on the left side blink (they are currently not used anyway), while Heartbeat, disk-IO and LAN in/out still work as usual. So, you will notice the 4 LEDs at once as well, but in addition you still have the possibility to see if LAN goes in/out (e.g. if you ping the machine) or if the heartbeat still works (and so your machine should still be reachable). Helge