From 4c55d7d518012f76eb48a87a66f3b4bee332b06a Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Thu, 15 Jan 2009 13:50:51 -0800 Subject: [PATCH] --- yaml --- r: 129661 b: refs/heads/master c: 47c33d9c1984ae4c5bd1f144024eacc14c5bc0c0 h: refs/heads/master i: 129659: 74b5bcfbc319db2838bfb71b9ca2818d2214a2c0 v: v3 --- [refs] | 2 +- trunk/Documentation/sysrq.txt | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index 95cd22840dc3..4e20560208e8 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 89365e264104b52da6a61c4e227bb5a934764fa7 +refs/heads/master: 47c33d9c1984ae4c5bd1f144024eacc14c5bc0c0 diff --git a/trunk/Documentation/sysrq.txt b/trunk/Documentation/sysrq.txt index 265f637b97d3..9e592c718afb 100644 --- a/trunk/Documentation/sysrq.txt +++ b/trunk/Documentation/sysrq.txt @@ -210,6 +210,24 @@ within a function called by handle_sysrq, you must be aware that you are in a lock (you are also in an interrupt handler, which means don't sleep!), so you must call __handle_sysrq_nolock instead. +* When I hit a SysRq key combination only the header appears on the console? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Sysrq output is subject to the same console loglevel control as all +other console output. This means that if the kernel was booted 'quiet' +as is common on distro kernels the output may not appear on the actual +console, even though it will appear in the dmesg buffer, and be accessible +via the dmesg command and to the consumers of /proc/kmsg. As a specific +exception the header line from the sysrq command is passed to all console +consumers as if the current loglevel was maximum. If only the header +is emitted it is almost certain that the kernel loglevel is too low. +Should you require the output on the console channel then you will need +to temporarily up the console loglevel using alt-sysrq-8 or: + + echo 8 > /proc/sysrq-trigger + +Remember to return the loglevel to normal after triggering the sysrq +command you are interested in. + * I have more questions, who can I ask? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ And I'll answer any questions about the registration system you got, also