Messages in this thread Patch in this message | | | Date | Tue, 22 Apr 2003 17:02:32 -0700 | From | Hanna Linder <> | Subject | [PATCH 2.5.68-mm1] lockmeter fix from tytso |
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Hi,
This is a fix from Ted Ts'o that I have tested and ported to the 2.5.68-mm1 kernel. Here is the note from Ted describing the problem:
> ridiculous hold times for a network spin lock that I *knew* wasn't > right. What was happening was that networking code was using > spin_lock_bh to enter the lock, did some work, then called a function > which called spin_unlock to temporarily release the lock, and then > called spin_lock. The top level function then called spin_unlock_bh. > Because spin_{lock,unlock}_bh wasn't being metered, the result was > ridiculous hold times.
Here is the patch. However, in order to test it I discovered that the config LOCKMETER part of the original patch has been dropped. I have included the code to add it back in for the i386 arch. Let me know if there was a reason to remove it from the config ;)
Thanks a lot for fixing the preempt problem too. I definitely owe you one...
Hanna
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diff -Nrup -Xdontdiff linux-2.5.68-mm1/arch/i386/Kconfig linux-lockmeter/arch/i386/Kconfig --- linux-2.5.68-mm1/arch/i386/Kconfig Tue Apr 22 14:45:33 2003 +++ linux-lockmeter/arch/i386/Kconfig Tue Apr 22 16:38:36 2003 @@ -1573,6 +1573,13 @@ 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 LOCKMETER + bool "Kernel lock metering" + depends on SMP + help + Say Y to enable kernel lock metering, which adds overhead to SMP locks, + but allows you to see various statistics using the lockstat command. + config KGDB bool "Include kgdb kernel debugger" depends on DEBUG_KERNEL diff -Nrup -Xdontdiff linux-2.5.68-mm1/include/linux/spinlock.h linux-lockmeter/include/linux/spinlock.h --- linux-2.5.68-mm1/include/linux/spinlock.h Tue Apr 22 14:45:45 2003 +++ linux-lockmeter/include/linux/spinlock.h Tue Apr 22 14:46:28 2003 @@ -400,6 +400,27 @@ do { \ ({preempt_enable(); local_bh_enable(); 0;});}) #ifdef CONFIG_LOCKMETER +#undef spin_lock +#undef spin_trylock +#undef spin_unlock +#undef spin_lock_irqsave +#undef spin_lock_irq +#undef spin_lock_bh +#undef read_lock +#undef read_unlock +#undef write_lock +#undef write_unlock +#undef write_trylock +#undef spin_unlock_bh +#undef read_lock_irqsave +#undef read_lock_irq +#undef read_lock_bh +#undef read_unlock_bh +#undef write_lock_irqsave +#undef write_lock_irq +#undef write_lock_bh +#undef write_unlock_bh + #define spin_lock(lock) \ do { \ preempt_disable(); \ @@ -414,6 +435,35 @@ do { \ preempt_enable(); \ } while (0) +#define spin_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_unlock_bh(lock) \ +do { \ + _metered_spin_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + + #define read_lock(lock) ({preempt_disable(); _metered_read_lock(lock);}) #define read_unlock(lock) ({_metered_read_unlock(lock); preempt_enable();}) #define write_lock(lock) ({preempt_disable(); _metered_write_lock(lock);}) @@ -426,6 +476,62 @@ do { \ preempt_enable_no_resched(); \ } while (0) +#define read_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_unlock_bh(lock) \ +do { \ + _metered_read_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + +#define write_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_unlock_bh(lock) \ +do { \ + _metered_write_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + #endif /* !CONFIG_LOCKMETER */ /* "lock on reference count zero" */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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