kernel/lib/Kconfig.debug, branch linux-2.6.28.y

block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT

2008-10-17T06:46:56Z

CONFIG_DEBUG_BLOCK_EXT_DEVT can break booting even on some modern distros. Add BIG FAT WARNING to keep people at a safe distance. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

driver core: basic infrastructure for per-module dynamic debug messages

2008-10-16T16:24:47Z

Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, /dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, /dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: . . . : Name of the module in which the debug call resides : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 " > dynamic_printk/modules Disable a module: $echo "set enabled=0 " > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron Signed-off-by: Greg Kroah-Hartman

Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memory-corruption-check', 'x86/early-printk', 'x86/xsave', 'x86/ptrace-v2', 'x86/quirks', 'x86/setup', 'x86/spinlocks' and 'x86/signal' into x86/core-v2

2008-10-12T13:50:02Z

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

2008-10-10T20:10:51Z

* 'rcu-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits) rcu: RCU-based detection of stalled CPUs for Classic RCU, fix rcu: RCU-based detection of stalled CPUs for Classic RCU rcu: add rcu_read_lock_sched() / rcu_read_unlock_sched() rcu: fix sparse shadowed variable warning doc/RCU: fix pseudocode in rcuref.txt rcuclassic: fix compiler warning rcu: use irq-safe locks rcuclassic: fix compilation NG rcu: fix locking cleanup fallout rcu: remove redundant ACCESS_ONCE definition from rcupreempt.c rcu: fix classic RCU locking cleanup lockdep problem rcu: trace fix possible mem-leak rcu: just rename call_rcu_bh instead of making it a macro rcu: remove list_for_each_rcu() rcu: fixes to include/linux/rcupreempt.h rcu: classic RCU locking and memory-barrier cleanups rcu: prevent console flood when one CPU sees another AWOL via RCU rcu, debug: detect stalled grace periods, cleanups rcu, debug: detect stalled grace periods rcu classic: new algorithm for callbacks-processing(v2) ...

block: add fault injection mechanism for faking request timeouts

2008-10-09T06:56:17Z

Only works for the generic request timer handling. Allows one to sporadically ignore request completions, thus exercising the timeout handling. Signed-off-by: Jens Axboe

init: DEBUG_BLOCK_EXT_DEVT requires explicit root= param

2008-10-09T06:56:11Z

DEBUG_BLOCK_EXT_DEVT shuffles SCSI and IDE device numbers and root device number set using rdev become meaningless. Root devices should be explicitly specified using textual names. Warn about it if root can't be found and DEBUG_BLOCK_EXT_DEVT is enabled. Also, add warning to the help text. Signed-off-by: Tejun Heo Cc: Bartlomiej Zolnierkiewicz Signed-off-by: Jens Axboe

Change default value of CONFIG_DEBUG_BLOCK_EXT_DEVT to 'n'

2008-10-09T06:56:11Z

It's a debug option that you would explicitly enable to test this feature, we should default it to 'n' to prevent accidental surprises for now. Signed-off-by: Jens Axboe

block: implement CONFIG_DEBUG_BLOCK_EXT_DEVT

2008-10-09T06:56:06Z

Extended devt introduces non-contiguos device numbers. This patch implements a debug option which forces most devt allocations to be from the extended area and spreads them out. This is enabled by default if DEBUG_KERNEL is set and achieves... 1. Detects code paths in kernel or userland which expect predetermined consecutive device numbers. 2. When something goes wrong, avoid corruption as adding to the minor of earlier partition won't lead to the wrong but valid device. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

rcu: RCU-based detection of stalled CPUs for Classic RCU

2008-10-03T08:36:08Z

This patch adds stalled-CPU detection to Classic RCU. This capability is enabled by a new config variable CONFIG_RCU_CPU_STALL_DETECTOR, which defaults disabled. This is a debugging feature to detect infinite loops in kernel code, not something that non-kernel-hackers would be expected to care about. This feature can detect looping CPUs in !PREEMPT builds and looping CPUs with preemption disabled in PREEMPT builds. This is essentially a port of this functionality from the treercu patch, replacing the stall debug patch that is already in tip/core/rcu (commit 67182ae1c4). The changes from the patch in tip/core/rcu include making the config variable name match that in treercu, changing from seconds to jiffies to avoid spurious warnings, and printing a boot message when this feature is enabled. Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar

Merge commit 'v2.6.27-rc6' into core/rcu

2008-09-10T06:35:40Z