linux-toradex.git/Documentation/sysrq.txt, branch v3.2

documentation: update sysrq.txt magic sysrq keys

2010-10-27T00:32:41+00:00

Update Documentation/sysrq.txt magic sysrq keys:

 - 'g' is for kgdb (not arch-specific);
 - add 2 new uses for 'v', remove the Voyager info;
 - add 'y' info (SPARC-64 specific);

Signed-off-by: Randy Dunlap 
Cc: Jason Wessel 
Cc: "David S. Miller" 
Cc: "James E.J. Bottomley" 
Cc: David Airlie 
Acked-by: Alexander Shishkin 
Signed-off-by: Linus Torvalds

Input: Documentation/sysrq.txt - update KEY_SYSRQ info

2010-05-19T17:14:15+00:00

While setting up sysrq operation on the XO laptop (which lacks a SysRq
key), i realized that the documentation was quite out of date.

Change documentation of SysRq to reflect current KEY_SYSRQ value.

Signed-off-by: Paul Fox 
Signed-off-by: Randy Dunlap 
Signed-off-by: Dmitry Torokhov

sysrq, kdump: make sysrq-c consistent

2009-07-30T02:10:36+00:00

commit d6580a9f15238b87e618310c862231ae3f352d2d ("kexec: sysrq: simplify
sysrq-c handler") changed the behavior of sysrq-c to unconditional
dereference of NULL pointer.  So in cases with CONFIG_KEXEC, where
crash_kexec() was directly called from sysrq-c before, now it can be said
that a step of "real oops" was inserted before starting kdump.

However, in contrast to oops via SysRq-c from keyboard which results in
panic due to in_interrupt(), oops via "echo c > /proc/sysrq-trigger" will
not become panic unless panic_on_oops=1.  It means that even if dump is
properly configured to be taken on panic, the sysrq-c from proc interface
might not start crashdump while the sysrq-c from keyboard can start
crashdump.  This confuses traditional users of kdump, i.e.  people who
expect sysrq-c to do common behavior in both of the keyboard and proc
interface.

This patch brings the keyboard and proc interface behavior of sysrq-c in
line, by forcing panic_on_oops=1 before oops in sysrq-c handler.

And some updates in documentation are included, to clarify that there is
no longer dependency with CONFIG_KEXEC, and that now the system can just
crash by sysrq-c if no dump mechanism is configured.

Signed-off-by: Hidetoshi Seto 
Cc: Lai Jiangshan 
Cc: Ken'ichi Ohmichi 
Acked-by: Neil Horman 
Acked-by: Vivek Goyal 
Cc: Brayan Arraes 
Cc: Eric W. Biederman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'tracing/core-v2' into tracing-for-linus

2009-04-01T22:49:02+00:00

Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c

filesystem freeze: allow SysRq emergency thaw to thaw frozen filesystems

2009-04-01T15:59:17+00:00

Now that the filesystem freeze operation has been elevated to the VFS, and
is just an ioctl away, some sort of safety net for unintentionally frozen
root filesystems may be in order.

The timeout thaw originally proposed did not get merged, but perhaps
something like this would be useful in emergencies.

For example, freeze /path/to/mountpoint may freeze your root filesystem if
you forgot that you had that unmounted.

I chose 'j' as the last remaining character other than 'h' which is sort
of reserved for help (because help is generated on any unknown character).

I've tested this on a non-root fs with multiple (nested) freezers, as well
as on a system rendered unresponsive due to a frozen root fs.

[randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled]
Signed-off-by: Eric Sandeen 
Cc: Takashi Sato 
Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'tracing/ftrace'; commit 'v2.6.29-rc2' into tracing/core

2009-01-18T19:15:05+00:00

sysrq documentation: document why the command header only is shown

2009-01-16T00:39:36+00:00

Document the interactions between loglevel and the sysrq output.  Also
document how to work round it should output be required on the console.

Signed-off-by: Andy Whitcroft 
Cc: Martin Mares 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysrq documentation: remove the redundant updated date

2009-01-16T00:39:36+00:00

git is maintaining the last update time much more accuratly than the
internal update time.  Remove it.

Signed-off-by: Andy Whitcroft 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysrq: fix ftrace help msg & doc.

2008-12-26T09:27:22+00:00

Impact: update documentation and help messages

We have a conventional method of explicitly stating the
sysrq action key in a sysrq help message, so change
dump-ftrace-buffer to use that method and add it to
Documentation/sysrq.txt.

Signed-off-by: Randy Dunlap 
Signed-off-by: Ingo Molnar

Merge branch 'v28-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2008-10-20T20:19:56+00:00

* 'v28-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (36 commits)
  fix documentation of sysrq-q really
  Fix documentation of sysrq-q
  timer_list: add base address to clock base
  timer_list: print cpu number of clockevents device
  timer_list: print real timer address
  NOHZ: restart tick device from irq_enter()
  NOHZ: split tick_nohz_restart_sched_tick()
  NOHZ: unify the nohz function calls in irq_enter()
  timers: fix itimer/many thread hang, fix
  timers: fix itimer/many thread hang, v3
  ntp: improve adjtimex frequency rounding
  timekeeping: fix rounding problem during clock update
  ntp: let update_persistent_clock() sleep
  hrtimer: reorder struct hrtimer to save 8 bytes on 64bit builds
  posix-timers: lock_timer: make it readable
  posix-timers: lock_timer: kill the bogus ->it_id check
  posix-timers: kill ->it_sigev_signo and ->it_sigev_value
  posix-timers: sys_timer_create: cleanup the error handling
  posix-timers: move the initialization of timer->sigq from send to create path
  posix-timers: sys_timer_create: simplify and s/tasklist/rcu/
  ...

Fix trivial conflicts due to sysrq-q description clahes in
Documentation/sysrq.txt and drivers/char/sysrq.c