From e8f7c70f44f75c827c04239b0ae5f0068b65b76e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 8 Jun 2011 01:51:02 +0200 Subject: sched: Make sleeping inside spinlock detection working in !CONFIG_PREEMPT Select CONFIG_PREEMPT_COUNT when we enable the sleeping inside spinlock detection, so that the preempt offset gets correctly incremented/decremented from preempt_disable()/preempt_enable(). This makes the preempt count eventually working in !CONFIG_PREEMPT when that debug option is set and thus fixes the detection of explicit preemption disabled sections under such config. Code that sleeps in explicitly preempt disabled section can be finally spotted in non-preemptible kernels. Signed-off-by: Frederic Weisbecker Acked-by: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra --- lib/Kconfig.debug | 1 + 1 file changed, 1 insertion(+) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 28afa4c5333c..a7dd7b547fea 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -650,6 +650,7 @@ config TRACE_IRQFLAGS config DEBUG_SPINLOCK_SLEEP bool "Spinlock debugging: sleep-inside-spinlock checking" + select PREEMPT_COUNT depends on DEBUG_KERNEL help If you say Y here, various routines which may sleep will become very -- cgit v1.2.3 From d902db1eb60387040fe541573083e47469db50ac Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 8 Jun 2011 19:31:56 +0200 Subject: sched: Generalize sleep inside spinlock detection 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 Acked-by: Paul E. McKenney Acked-by: Randy Dunlap Cc: Peter Zijlstra Cc: Ingo Molnar --- 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(-) (limited to 'lib') diff --git a/Documentation/DocBook/kernel-hacking.tmpl b/Documentation/DocBook/kernel-hacking.tmpl index 7b3f49363413..07a9c48de5a2 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 - CONFIG_DEBUG_SPINLOCK_SLEEP on, and it will warn + CONFIG_DEBUG_ATOMIC_SLEEP 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 da0382daa395..7b13be41c085 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 f3f1a469443c..83f5f5b365a3 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 2df4576f1173..cb5507b1ac81 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 951415bbab0c..4c741d6bc048 100644 --- a/Documentation/zh_CN/SubmitChecklist +++ b/Documentation/zh_CN/SubmitChecklist @@ -67,7 +67,7 @@ Linux 12ѾͨCONFIG_PREEMPT, CONFIG_DEBUG_PREEMPT, CONFIG_DEBUG_SLAB, CONFIG_DEBUG_PAGEALLOC, CONFIG_DEBUG_MUTEXES, - CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_SPINLOCK_SLEEPԣͬʱ + CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_ATOMIC_SLEEPԣͬʱ ʹܡ 13Ѿʹû߲ʹ CONFIG_SMP CONFIG_PREEMPTִʱ䡣 diff --git a/include/linux/kernel.h b/include/linux/kernel.h index fb0e7329fee1..24b489f66592 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 90ad7cf2b290..a5f318b8d659 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 a7dd7b547fea..81a4f3302bc8 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" -- cgit v1.2.3