linux-toradex.git/include/linux/debug_locks.h, branch v2.6.38.6

lockdep: Remove __debug_show_held_locks

2010-08-17T07:11:10+00:00

There is no longer any functional difference between
__debug_show_held_locks() and debug_show_held_locks(),
so remove the former.

Signed-off-by: John Kacur 
Cc: Peter Zijlstra 
LKML-Reference: <1281021054-4228-1-git-send-email-jkacur@redhat.com>
Signed-off-by: Ingo Molnar

lockdep: warn about lockdep disabling after kernel taint, fix

2009-04-14T09:11:52+00:00

Impact: build fix for Sparc and s390

Stephen Rothwell reported that the Sparc build broke:

 In file included from kernel/panic.c:12:
 include/linux/debug_locks.h: In function '__debug_locks_off':
 include/linux/debug_locks.h:15: error: implicit declaration of function 'xchg'

due to:

 9eeba61: lockdep: warn about lockdep disabling after kernel taint

There is some inconsistency between architectures about where exactly
xchg() is defined.

The traditional place is in system.h but the more logical point for it
is in atomic.h - where most architectures (especially new ones) have
it defined. These architecture also still offer it via system.h.

Some, such as Sparc or s390 only have it in asm/system.h and not available
via asm/atomic.h at all.

Use the widest set of headers in debug_locks.h and also include asm/system.h.

Reported-by: Stephen Rothwell 
Cc: Frederic Weisbecker 
Cc: "David S. Miller" 
Cc: Linus Torvalds 
LKML-Reference: <20090414144317.026498df.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar

lockdep: warn about lockdep disabling after kernel taint

2009-04-12T14:10:51+00:00

Impact: provide useful missing info for developers

Kernel taint can occur in several situations such as warnings,
load of prorietary or staging modules, bad page, etc...

But when such taint happens, a developer might still be working on
the kernel, expecting that lockdep is still enabled. But a taint
disables lockdep without ever warning about it.
Such a kernel behaviour doesn't really help for kernel development.

This patch adds this missing warning.

Since the taint is done most of the time after the main message that
explain the real source issue, it seems safe to warn about it inside
add_taint() so that it appears at last, without hurting the main
information.

v2: Use a generic helper to disable lockdep instead of an
    open coded xchg().

Signed-off-by: Frederic Weisbecker 
Cc: Peter Zijlstra 
LKML-Reference: <1239412638-6739-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar

lock debug: sit tight when we are already in a panic

2008-09-12T09:11:21+00:00

in:

  > http://bugzilla.kernel.org/show_bug.cgi?id=11543

The panic code called the kexec code which called mutex_trylock() which
called spin_lock_mutex() which then stupidly went and blurted a load of
debug stuff because of in_interrupt().

Keep the lock debug code from escallating an already crappy situation.

Signed-off-by: Ingo Molnar

Move _RET_IP_ and _THIS_IP_ to include/linux/kernel.h

2008-07-05T20:10:50+00:00

These two macros are useful beyond lock debugging. Moved definitions from
include/linux/debug_locks.h to include/linux/kernel.h, so code that needs
them does not have to include the former, which would have been a less
intuitive choice of a header.

Signed-off-by: Eduard - Gabriel Munteanu 
Acked-by: Pekka Enberg 
Signed-off-by: Linus Torvalds

softlockup: automatically detect hung TASK_UNINTERRUPTIBLE tasks

2008-01-25T20:08:02+00:00

this patch extends the soft-lockup detector to automatically
detect hung TASK_UNINTERRUPTIBLE tasks. Such hung tasks are
printed the following way:

 ------------------>
 INFO: task prctl:3042 blocked for more than 120 seconds.
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message
 prctl         D fd5e3793     0  3042   2997
        f6050f38 00000046 00000001 fd5e3793 00000009 c06d8264 c06dae80 00000286
        f6050f40 f6050f00 f7d34d90 f7d34fc8 c1e1be80 00000001 f6050000 00000000
        f7e92d00 00000286 f6050f18 c0489d1a f6050f40 00006605 00000000 c0133a5b
 Call Trace:
  [] schedule_timeout+0x6d/0x8b
  [] schedule_timeout_uninterruptible+0x15/0x17
  [] msleep+0x10/0x16
  [] sys_prctl+0x30/0x1e2
  [] sysenter_past_esp+0x5f/0xa5
  =======================
 2 locks held by prctl/3042:
 #0:  (&sb->s_type->i_mutex_key#5){--..}, at: [] do_fsync+0x38/0x7a
 #1:  (jbd_handle){--..}, at: [] journal_start+0xc7/0xe9
 <------------------

the current default timeout is 120 seconds. Such messages are printed
up to 10 times per bootup. If the system has crashed already then the
messages are not printed.

if lockdep is enabled then all held locks are printed as well.

this feature is a natural extension to the softlockup-detector (kernel
locked up without scheduling) and to the NMI watchdog (kernel locked up
with IRQs disabled).

[ Gautham R Shenoy : CPU hotplug fixes. ]
[ Andrew Morton : build warning fix. ]

Signed-off-by: Ingo Molnar 
Signed-off-by: Arjan van de Ven

[PATCH] lock debugging: fix DEBUG_LOCKS_WARN_ON() & debug_locks_silent

2006-12-22T16:55:48+00:00

Matthew Wilcox noticed that the debug_locks_silent use should be inverted
in DEBUG_LOCKS_WARN_ON().  This bug was causing spurious stacktraces and
incorrect failures in the locking self-test on the parisc kernel.

Bug-found-by: Matthew Wilcox 
Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] lockdep: show more details about self-test failures

2006-12-07T16:39:43+00:00

Make the locking self-test failures (of 'FAILURE' type) easier to debug by
printing more information.

Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Need forward decl of task_struct in linux/debug_locks.h

2006-10-04T12:45:23+00:00

Signed-off-by: Kyle McMartin

[PATCH] debug_locks.h: add "struct task_struct;"

2006-08-06T15:57:47+00:00

Removes many, many "declared inside parameter list" warnings on parisc.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds