Re: [PATCH 4/4] sched: Generalize sleep inside spinlock detection

Paul E. McKenney
2011-06-08T19:41:18Z

On Wed, Jun 08, 2011 at 07:48:35PM +0200, Frederic Weisbecker wrote:
> The sleeping inside spinlock detection is actually used
> for more general sleeping inside atomic sections
> debugging: preemption disabled, rcu read side critical
> sections, interrupts, interrupt disabled, etc...
>
> Change the name of the config and its help section to
> reflect its more general role.
>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Randy Dunlap <randy.dunlap@oracle.com>
> ---
> Documentation/DocBook/kernel-hacking.tmpl | 2 +-
> Documentation/SubmitChecklist | 2 +-
> Documentation/development-process/4.Coding | 2 +-
> Documentation/ja_JP/SubmitChecklist | 2 +-
> Documentation/zh_CN/SubmitChecklist | 2 +-
> include/linux/kernel.h | 2 +-
> kernel/sched.c | 2 +-
> lib/Kconfig.debug | 8 +++++---
> 8 files changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/DocBook/kernel-hacking.tmpl b/Documentation/DocBook/kernel-hacking.tmpl
> index 7b3f493..07a9c48 100644
> --- a/Documentation/DocBook/kernel-hacking.tmpl
> +++ b/Documentation/DocBook/kernel-hacking.tmpl
> @@ -409,7 +409,7 @@ cond_resched(); /* Will sleep */
>
>
> You should always compile your kernel
> - <symbol>CONFIG_DEBUG_SPINLOCK_SLEEP</symbol> on, and it will warn
> + <symbol>CONFIG_DEBUG_ATOMIC_SLEEP</symbol> on, and it will warn
> you if you break these rules. If you do break
> the rules, you will eventually lock up your box.
>
> diff --git a/Documentation/SubmitChecklist b/Documentation/SubmitChecklist
> index da0382d..7b13be4 100644
> --- a/Documentation/SubmitChecklist
> +++ b/Documentation/SubmitChecklist
> @@ -53,7 +53,7 @@ kernel patches.
>
> 12: Has been tested with CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT,
> CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES,
> - CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEP all simultaneously
> + CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_ATOMIC_SLEEP all simultaneously
> enabled.
>
> 13: Has been build- and runtime tested with and without CONFIG_SMP and
> diff --git a/Documentation/development-process/4.Coding b/Documentation/development-process/4.Coding
> index f3f1a46..83f5f5b 100644
> --- a/Documentation/development-process/4.Coding
> +++ b/Documentation/development-process/4.Coding
> @@ -244,7 +244,7 @@ testing purposes. In particular, you should turn on:
> - DEBUG_SLAB can find a variety of memory allocation and use errors; it
> should be used on most development kernels.
>
> - - DEBUG_SPINLOCK, DEBUG_SPINLOCK_SLEEP, and DEBUG_MUTEXES will find a
> + - DEBUG_SPINLOCK, DEBUG_ATOMIC_SLEEP, and DEBUG_MUTEXES will find a
> number of common locking errors.
>
> There are quite a few other debugging options, some of which will be
> diff --git a/Documentation/ja_JP/SubmitChecklist b/Documentation/ja_JP/SubmitChecklist
> index 2df4576..cb5507b 100644
> --- a/Documentation/ja_JP/SubmitChecklist
> +++ b/Documentation/ja_JP/SubmitChecklist
> @@ -68,7 +68,7 @@ Linux カーネルパッチ投稿者向けチェックリスト
>
> 12: CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB,
> CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES, CONFIG_DEBUG_SPINLOCK,
> - CONFIG_DEBUG_SPINLOCK_SLEEP これら全てを同時に有効にして動作確認を
> + CONFIG_DEBUG_ATOMIC_SLEEP これら全てを同時に有効にして動作確認を
> 行ってください。
>
> 13: CONFIG_SMP, CONFIG_PREEMPT を有効にした場合と無効にした場合の両方で
> diff --git a/Documentation/zh_CN/SubmitChecklist b/Documentation/zh_CN/SubmitChecklist
> index 951415b..4c741d6 100644
> --- a/Documentation/zh_CN/SubmitChecklist
> +++ b/Documentation/zh_CN/SubmitChecklist
> @@ -67,7 +67,7 @@ Linux
>
> 12???Ѿ?ͨ??CONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT,
> CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES,
> - CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEP???ԣ?????ͬʱ??
> + CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_ATOMIC_SLEEP???ԣ?????ͬʱ??
> ʹ?ܡ?
>
> 13???Ѿ???????????ʹ?û??߲?ʹ?? CONFIG_SMP ?? CONFIG_PREEMPT????ִ??ʱ?䡣
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index fb0e732..24b489f 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -121,7 +121,7 @@ extern int _cond_resched(void);
> # define might_resched() do { } while (0)
> #endif
>
> -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
> +#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
> void __might_sleep(const char *file, int line, int preempt_offset);
> /**
> * might_sleep - annotation for functions that can sleep
> diff --git a/kernel/sched.c b/kernel/sched.c
> index 90ad7cf..a5f318b 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -8018,7 +8018,7 @@ void __init sched_init(void)
> scheduler_running = 1;
> }
>
> -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
> +#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
> static inline int preempt_count_equals(int preempt_offset)
> {
> int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index a7dd7b5..81a4f33 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -648,13 +648,15 @@ config TRACE_IRQFLAGS
> Enables hooks to interrupt enabling and disabling for
> either tracing or lock debugging.
>
> -config DEBUG_SPINLOCK_SLEEP
> - bool "Spinlock debugging: sleep-inside-spinlock checking"
> +config DEBUG_ATOMIC_SLEEP
> + bool "Sleep inside atomic section checking"
> select PREEMPT_COUNT
> depends on DEBUG_KERNEL
> help
> If you say Y here, various routines which may sleep will become very
> - noisy if they are called with a spinlock held.
> + noisy if they are called inside atomic sections: when a spinlock is
> + held, inside an rcu read side critical section, inside preempt disabled
> + sections, inside an interrupt, etc...
>
> config DEBUG_LOCKING_API_SELFTESTS
> bool "Locking API boot-time self-tests"
> --
> 1.7.5.4
>