[PATCH v3 18/22] sys-rq: Add option to soft dump
From: Mike Waychison <hidden>
Date: 2010-12-14 21:31:39
Also in:
linux-api, lkml
Subsystem:
documentation, the rest, tty layer and serial drivers · Maintainers:
Jonathan Corbet, Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
It is very useful to provide some means to force the kernel logs to make it out via the kmsg_oops implementations on the console. Add a new option 'Y' to sysrq to allow dumping of logs to kmsg_dumper drivers. Signed-off-by: Mike Waychison <redacted> --- Changelog: - v3 - Added a note to Documentation/sysrq.txt about the command. TODO: Figure out a better letter? Can we reuse 'v'? --- Documentation/sysrq.txt | 4 ++++ drivers/tty/sysrq.c | 14 +++++++++++++- 2 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt
index 312e375..3c7ee87 100644
--- a/Documentation/sysrq.txt
+++ b/Documentation/sysrq.txt@@ -118,6 +118,10 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 'x' - Used by xmon interface on ppc/powerpc platforms. 'y' - Show global CPU Registers [SPARC-64 specific] +'y' - Trigger a 'soft' kmsg dump. Any kmsg_dump clients (mtdoops, + netoops, ramoops) will initiate a dump to their respective + backend. + 'z' - Dump the ftrace buffer
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index c556ed9..f79f34a 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c@@ -41,6 +41,7 @@ #include <linux/oom.h> #include <linux/slab.h> #include <linux/input.h> +#include <linux/kmsg_dump.h> #include <asm/ptrace.h> #include <asm/irq_regs.h>
@@ -395,6 +396,17 @@ static struct sysrq_key_op sysrq_unrt_op = { .enable_mask = SYSRQ_ENABLE_RTNICE, }; +static void sysrq_handle_softdump(int key) +{ + kmsg_dump(KMSG_DUMP_SOFT, NULL); +} +static struct sysrq_key_op sysrq_softdump_op = { + .handler = sysrq_handle_softdump, + .help_msg = "soft-dump(Y)", + .action_msg = "Trigger a soft dump", + .enable_mask = SYSRQ_ENABLE_DUMP, +}; + /* Key Operations table and lock */ static DEFINE_SPINLOCK(sysrq_key_table_lock);
@@ -451,7 +463,7 @@ static struct sysrq_key_op *sysrq_key_table[36] = { /* x: May be registered on ppc/powerpc for xmon */ NULL, /* x */ /* y: May be registered on sparc64 for global register dump */ - NULL, /* y */ + &sysrq_softdump_op, /* y */ &sysrq_ftrace_dump_op, /* z */ };