* [PATCH 1/2] Spinlock timeout
@ 2004-07-06 21:16 Jake Moilanen
2004-07-06 21:39 ` Stephen Hemminger
[not found] ` <20040706204314.GA16951@galt.devicelogics.com>
0 siblings, 2 replies; 3+ messages in thread
From: Jake Moilanen @ 2004-07-06 21:16 UTC (permalink / raw)
To: Andrew Morton, Linus Torvalds; +Cc: linux-kernel
This will cause a BUG() when a spinlock is held for longer then X
seconds. It is useful for catching deadlocks since not all archs
have a NMI watchdog.
It is also helpful to find locks that are held too long.
Please comment or apply.
Thanks,
Jake
Signed-off-by: Jake Moilanen <moilanen@austin.ibm.com>
---
diff -puN arch/alpha/Kconfig~spinlock-timeout arch/alpha/Kconfig
--- linux-2.6/arch/alpha/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/alpha/Kconfig Tue Jul 6 15:16:51 2004
@@ -664,6 +664,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_RWLOCK
bool "Read-write spinlock debugging"
depends on DEBUG_KERNEL
diff -puN arch/alpha/defconfig~spinlock-timeout arch/alpha/defconfig
--- linux-2.6/arch/alpha/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/alpha/defconfig Tue Jul 6 15:16:51 2004
@@ -868,6 +868,7 @@ CONFIG_MATHEMU=y
# CONFIG_DEBUG_SLAB is not set
CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_DEBUG_RWLOCK is not set
# CONFIG_DEBUG_SEMAPHORE is not set
CONFIG_DEBUG_INFO=y
diff -puN arch/arm/Kconfig~spinlock-timeout arch/arm/Kconfig
--- linux-2.6/arch/arm/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/arm/Kconfig Tue Jul 6 15:16:51 2004
@@ -721,6 +721,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_WAITQ
bool "Wait queue debugging"
depends on DEBUG_KERNEL
diff -puN arch/arm/defconfig~spinlock-timeout arch/arm/defconfig
--- linux-2.6/arch/arm/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/arm/defconfig Tue Jul 6 15:16:51 2004
@@ -507,5 +507,6 @@ CONFIG_FRAME_POINTER=y
CONFIG_DEBUG_ERRORS=y
CONFIG_DEBUG_USER=y
# CONFIG_DEBUG_INFO is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_LL=y
diff -puN arch/arm26/Kconfig~spinlock-timeout arch/arm26/Kconfig
--- linux-2.6/arch/arm26/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/arm26/Kconfig Tue Jul 6 15:16:51 2004
@@ -284,6 +284,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_WAITQ
bool "Wait queue debugging"
depends on DEBUG_KERNEL
diff -puN arch/arm26/defconfig~spinlock-timeout arch/arm26/defconfig
--- linux-2.6/arch/arm26/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/arm26/defconfig Tue Jul 6 15:16:51 2004
@@ -344,6 +344,7 @@ CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_SLAB=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_SPINLOCK=y
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_DEBUG_WAITQ=y
CONFIG_DEBUG_BUGVERBOSE=y
CONFIG_DEBUG_ERRORS=y
diff -puN arch/i386/Kconfig~spinlock-timeout arch/i386/Kconfig
--- linux-2.6/arch/i386/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/i386/Kconfig Tue Jul 6 15:16:51 2004
@@ -1237,6 +1237,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_PAGEALLOC
bool "Page alloc debugging"
depends on DEBUG_KERNEL
diff -puN arch/i386/defconfig~spinlock-timeout arch/i386/defconfig
--- linux-2.6/arch/i386/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/i386/defconfig Tue Jul 6 15:16:51 2004
@@ -1216,6 +1216,7 @@ CONFIG_OPROFILE=y
# CONFIG_DEBUG_KERNEL is not set
CONFIG_EARLY_PRINTK=y
CONFIG_DEBUG_SPINLOCK_SLEEP=y
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_FRAME_POINTER is not set
CONFIG_X86_FIND_SMP_CONFIG=y
CONFIG_X86_MPPARSE=y
diff -puN arch/ia64/Kconfig~spinlock-timeout arch/ia64/Kconfig
--- linux-2.6/arch/ia64/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ia64/Kconfig Tue Jul 6 15:16:51 2004
@@ -459,6 +459,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config IA64_DEBUG_CMPXCHG
bool "Turn on compare-and-exchange bug checking (slow!)"
depends on DEBUG_KERNEL
diff -puN arch/ia64/defconfig~spinlock-timeout arch/ia64/defconfig
--- linux-2.6/arch/ia64/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ia64/defconfig Tue Jul 6 15:16:51 2004
@@ -1093,6 +1093,7 @@ CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SLAB is not set
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_IA64_DEBUG_CMPXCHG is not set
# CONFIG_IA64_DEBUG_IRQ is not set
CONFIG_DEBUG_INFO=y
diff -puN arch/mips/Kconfig~spinlock-timeout arch/mips/Kconfig
--- linux-2.6/arch/mips/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/mips/Kconfig Tue Jul 6 15:16:51 2004
@@ -1314,6 +1314,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config RTC_DS1742
bool "DS1742 BRAM/RTC support"
depends on TOSHIBA_JMR3927 || TOSHIBA_RBTX4927
diff -puN arch/mips/defconfig~spinlock-timeout arch/mips/defconfig
--- linux-2.6/arch/mips/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/mips/defconfig Tue Jul 6 15:16:51 2004
@@ -122,6 +122,7 @@ CONFIG_CPU_HAS_LLDSCD=y
CONFIG_CPU_HAS_SYNC=y
# CONFIG_PREEMPT is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
#
# Bus options (PCI, PCMCIA, EISA, ISA, TC)
diff -puN arch/ppc/Kconfig~spinlock-timeout arch/ppc/Kconfig
--- linux-2.6/arch/ppc/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ppc/Kconfig Tue Jul 6 15:16:51 2004
@@ -1166,6 +1166,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config KGDB
bool "Include kgdb kernel debugger"
depends on DEBUG_KERNEL
diff -puN arch/ppc/defconfig~spinlock-timeout arch/ppc/defconfig
--- linux-2.6/arch/ppc/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ppc/defconfig Tue Jul 6 15:16:51 2004
@@ -1223,6 +1223,7 @@ CONFIG_ZLIB_DEFLATE=y
# Kernel hacking
#
# CONFIG_DEBUG_KERNEL is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_BOOTX_TEXT=y
#
diff -puN arch/ppc64/Kconfig~spinlock-timeout arch/ppc64/Kconfig
--- linux-2.6/arch/ppc64/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ppc64/Kconfig Tue Jul 6 15:16:51 2004
@@ -364,6 +364,20 @@ config MAGIC_SYSRQ
keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
unless you really know what this hack does.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUGGER
bool "Enable debugger hooks"
depends on DEBUG_KERNEL
diff -puN arch/ppc64/defconfig~spinlock-timeout arch/ppc64/defconfig
--- linux-2.6/arch/ppc64/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/ppc64/defconfig Tue Jul 6 15:16:51 2004
@@ -1054,6 +1054,7 @@ CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_STACK_USAGE=y
# CONFIG_DEBUG_SLAB is not set
CONFIG_MAGIC_SYSRQ=y
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_DEBUGGER=y
CONFIG_XMON=y
CONFIG_XMON_DEFAULT=y
diff -puN arch/s390/Kconfig~spinlock-timeout arch/s390/Kconfig
--- linux-2.6/arch/s390/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/s390/Kconfig Tue Jul 6 15:16:51 2004
@@ -423,6 +423,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
endmenu
source "security/Kconfig"
diff -puN arch/s390/defconfig~spinlock-timeout arch/s390/defconfig
--- linux-2.6/arch/s390/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/s390/defconfig Tue Jul 6 15:16:51 2004
@@ -476,6 +476,7 @@ CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SLAB is not set
# CONFIG_DEBUG_INFO is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
#
# Security options
diff -puN arch/sh/Kconfig~spinlock-timeout arch/sh/Kconfig
--- linux-2.6/arch/sh/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sh/Kconfig Tue Jul 6 15:16:51 2004
@@ -675,6 +675,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config SH_STANDARD_BIOS
bool "Use LinuxSH standard BIOS"
help
diff -puN arch/sh/defconfig~spinlock-timeout arch/sh/defconfig
--- linux-2.6/arch/sh/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sh/defconfig Tue Jul 6 15:16:51 2004
@@ -351,6 +351,7 @@ CONFIG_MSDOS_PARTITION=y
#
# CONFIG_MAGIC_SYSRQ is not set
# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_SH_STANDARD_BIOS=y
CONFIG_SH_EARLY_PRINTK=y
# CONFIG_KGDB is not set
diff -puN arch/sparc/Kconfig~spinlock-timeout arch/sparc/Kconfig
--- linux-2.6/arch/sparc/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sparc/Kconfig Tue Jul 6 15:16:51 2004
@@ -440,6 +440,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_BUGVERBOSE
bool "Verbose BUG() reporting (adds 70K)"
depends on DEBUG_KERNEL
diff -puN arch/sparc/defconfig~spinlock-timeout arch/sparc/defconfig
--- linux-2.6/arch/sparc/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sparc/defconfig Tue Jul 6 15:16:51 2004
@@ -611,6 +611,7 @@ CONFIG_DEBUG_KERNEL=y
# CONFIG_DEBUG_SLAB is not set
CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_DEBUG_HIGHMEM is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
# CONFIG_DEBUG_BUGVERBOSE is not set
diff -puN arch/sparc64/Kconfig~spinlock-timeout arch/sparc64/Kconfig
--- linux-2.6/arch/sparc64/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sparc64/Kconfig Tue Jul 6 15:16:51 2004
@@ -658,6 +658,20 @@ config DEBUG_SPINLOCK_SLEEP
If you say Y here, various routines which may sleep will become very
noisy if they are called with a spinlock held.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_BUGVERBOSE
bool "Verbose BUG() reporting (adds 70K)"
depends on DEBUG_KERNEL
diff -puN arch/sparc64/defconfig~spinlock-timeout arch/sparc64/defconfig
--- linux-2.6/arch/sparc64/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/sparc64/defconfig Tue Jul 6 15:16:51 2004
@@ -1718,6 +1718,7 @@ CONFIG_DEBUG_KERNEL=y
CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_DEBUG_SPINLOCK_SLEEP is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_DEBUG_BUGVERBOSE is not set
# CONFIG_DEBUG_DCFLUSH is not set
# CONFIG_DEBUG_INFO is not set
diff -puN arch/um/Kconfig~spinlock-timeout arch/um/Kconfig
--- linux-2.6/arch/um/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/um/Kconfig Tue Jul 6 15:16:51 2004
@@ -222,6 +222,20 @@ config DEBUG_SLAB
config DEBUG_SPINLOCK
bool "Debug spinlocks usage"
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
config DEBUG_INFO
bool "Enable kernel debugging symbols"
help
diff -puN arch/um/defconfig~spinlock-timeout arch/um/defconfig
--- linux-2.6/arch/um/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/um/defconfig Tue Jul 6 15:16:51 2004
@@ -399,6 +399,7 @@ CONFIG_MTD_BLKMTD=m
#
# CONFIG_DEBUG_SLAB is not set
# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
CONFIG_DEBUG_INFO=y
CONFIG_FRAME_POINTER=y
CONFIG_PT_PROXY=y
diff -puN arch/x86_64/Kconfig~spinlock-timeout arch/x86_64/Kconfig
--- linux-2.6/arch/x86_64/Kconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/x86_64/Kconfig Tue Jul 6 15:16:51 2004
@@ -427,6 +427,20 @@ config DEBUG_SPINLOCK
best used in conjunction with the NMI watchdog so that spinlock
deadlocks are also debuggable.
+config SPINLOCK_TIMEOUT
+ bool "Spinlocks timeout"
+ depends on DEBUG_KERNEL && SMP
+ help
+ If you say Y here, the spinlocks will timeout after X number
+ of seconds. This is useful for catching deadlocks, and make sure
+ locks are not held too long.
+
+config SPINLOCK_TIMEOUT_TIME
+ int "Spinlock timeout time in seconds (1-43200)"
+ range 1 43200
+ depends on SPINLOCK_TIMEOUT
+ default "10"
+
# !SMP for now because the context switch early causes GPF in segment reloading
# and the GS base checking does the wrong thing then, causing a hang.
config CHECKING
diff -puN arch/x86_64/defconfig~spinlock-timeout arch/x86_64/defconfig
--- linux-2.6/arch/x86_64/defconfig~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/arch/x86_64/defconfig Tue Jul 6 15:16:51 2004
@@ -814,6 +814,7 @@ CONFIG_DEBUG_KERNEL=y
# CONFIG_DEBUG_SLAB is not set
CONFIG_MAGIC_SYSRQ=y
# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_SPINLOCK_TIMEOUT is not set
# CONFIG_INIT_DEBUG is not set
# CONFIG_DEBUG_INFO is not set
# CONFIG_FRAME_POINTER is not set
diff -puN include/linux/jiffies.h~spinlock-timeout include/linux/jiffies.h
--- linux-2.6/include/linux/jiffies.h~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/include/linux/jiffies.h Tue Jul 6 15:16:51 2004
@@ -3,8 +3,6 @@
#include <linux/kernel.h>
#include <linux/types.h>
-#include <linux/spinlock.h>
-#include <linux/seqlock.h>
#include <asm/system.h>
#include <asm/param.h> /* for HZ */
diff -puN include/linux/spinlock.h~spinlock-timeout include/linux/spinlock.h
--- linux-2.6/include/linux/spinlock.h~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/include/linux/spinlock.h Tue Jul 6 15:16:51 2004
@@ -38,6 +38,25 @@
#ifdef CONFIG_SMP
#include <asm/spinlock.h>
+#if defined(CONFIG_SPINLOCK_TIMEOUT)
+
+#include <linux/jiffies.h>
+
+#define SPINLOCK_TIMEOUT CONFIG_SPINLOCK_TIMEOUT_TIME
+
+/*
+ * There are paths where jiffies won't be updated and
+ * SPINLOCK_TIMEOUT will not work. To ensure they work, it is best
+ * to have every arch implement their own SPINLOCK_TIMEOUT routines
+ * that use hardware timers.
+ */
+#ifndef ARCH_HAS_SPINLOCK_TIMEOUT
+#define get_spinlock_timeout() (jiffies + (SPINLOCK_TIMEOUT * HZ))
+#define check_spinlock_timeout(timeout) (time_after_eq(jiffies, timeout))
+#endif /* !ARCH_HASH_SPINLOCK_TIMEOUT */
+
+#endif /* CONFIG_SPINLOCK_TIMEOUT */
+
#else
#if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK)
@@ -216,12 +235,28 @@ do { \
} while (0)
#else
+#if defined(CONFIG_SPINLOCK_TIMEOUT)
+
+static inline void spin_lock(spinlock_t * lock) {
+ unsigned long timeout = get_spinlock_timeout();
+
+ preempt_disable();
+ do {
+ if (check_spinlock_timeout(timeout))
+ BUG();
+ } while (!_raw_spin_trylock(lock));
+}
+
+#else /* CONFIG_SPINLOCK_TIMEOUT */
+
#define spin_lock(lock) \
do { \
preempt_disable(); \
_raw_spin_lock(lock); \
} while(0)
+#endif /* CONFIG_SPINLOCK_TIMEOUT */
+
#define write_lock(lock) \
do { \
preempt_disable(); \
@@ -256,22 +291,19 @@ do { \
#define spin_lock_irqsave(lock, flags) \
do { \
local_irq_save(flags); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
+ spin_lock(lock); \
} while (0)
#define spin_lock_irq(lock) \
do { \
local_irq_disable(); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
+ spin_lock(lock); \
} while (0)
#define spin_lock_bh(lock) \
do { \
local_bh_disable(); \
- preempt_disable(); \
- _raw_spin_lock(lock); \
+ spin_lock(lock); \
} while (0)
#define read_lock_irqsave(lock, flags) \
diff -puN kernel/sched.c~spinlock-timeout kernel/sched.c
--- linux-2.6/kernel/sched.c~spinlock-timeout Tue Jul 6 15:16:51 2004
+++ linux-2.6-moilanen/kernel/sched.c Tue Jul 6 15:16:51 2004
@@ -3022,14 +3022,23 @@ EXPORT_SYMBOL(__might_sleep);
*/
void __sched __preempt_spin_lock(spinlock_t *lock)
{
+#if defined(CONFIG_SPINLOCK_TIMEOUT)
+ unsigned long timeout = get_spinlock_timeout();
+#endif
+
if (preempt_count() > 1) {
_raw_spin_lock(lock);
return;
}
do {
preempt_enable();
- while (spin_is_locked(lock))
+ while (spin_is_locked(lock)) {
+#if defined(CONFIG_SPINLOCK_TIMEOUT)
+ if (check_spinlock_timeout(timeout))
+ BUG();
+#endif
cpu_relax();
+ }
preempt_disable();
} while (!_raw_spin_trylock(lock));
}
_
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] Spinlock timeout
2004-07-06 21:16 [PATCH 1/2] Spinlock timeout Jake Moilanen
@ 2004-07-06 21:39 ` Stephen Hemminger
[not found] ` <20040706204314.GA16951@galt.devicelogics.com>
1 sibling, 0 replies; 3+ messages in thread
From: Stephen Hemminger @ 2004-07-06 21:39 UTC (permalink / raw)
To: linux-kernel
On Tue, 6 Jul 2004 16:16:27 -0500
Jake Moilanen <moilanen@austin.ibm.com> wrote:
> This will cause a BUG() when a spinlock is held for longer then X
> seconds. It is useful for catching deadlocks since not all archs
> have a NMI watchdog.
>
> It is also helpful to find locks that are held too long.
>
> Please comment or apply.
>
> Thanks,
Just don't ever run on a production or benchmark system because there are
cases where a lock can get hot and statistically take a real long time.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] Spinlock timeout
[not found] ` <20040706204314.GA16951@galt.devicelogics.com>
@ 2004-07-06 22:15 ` Jake Moilanen
0 siblings, 0 replies; 3+ messages in thread
From: Jake Moilanen @ 2004-07-06 22:15 UTC (permalink / raw)
To: jmerkey; +Cc: akpm, torvalds, linux-kernel
On Tue, 6 Jul 2004 14:43:14 -0600
jmerkey@galt.devicelogics.com wrote:
>
>
> You should also for the UP case of Linux keep a counter
> and call BUG() when someone calls a spinlock twice rather than
> just push, cli, and pop interrupt flags. Guess what, this
> allows you to catch most deadlock bugs with spinlocks
Isn't this what CONFIG_DEBUG_SPINLOCK is for?
Thanks,
Jake
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2004-07-06 22:15 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-07-06 21:16 [PATCH 1/2] Spinlock timeout Jake Moilanen
2004-07-06 21:39 ` Stephen Hemminger
[not found] ` <20040706204314.GA16951@galt.devicelogics.com>
2004-07-06 22:15 ` Jake Moilanen
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®