Re: [-mm PATCH] RCU: debug sleep check

From: Andrew Morton
Date: Sun Sep 24 2006 - 14:59:14 EST

On Mon, 25 Sep 2006 00:05:09 +0530
Dipankar Sarma <dipankar@xxxxxxxxxx> wrote:

> Add a debug check for rcu read-side critical section code calling
> a function that might sleep which is illegal. The check is enabled only

Does this actually change anything? rcu_read_lock is preempt_disable(), and
might_sleep() already triggers if called inside preempt_disable().

> -#define rcu_read_lock() __rcu_read_lock()
> +#define rcu_read_lock() \
> + do { \
> + rcu_add_read_count(); \
> + __rcu_read_lock(); \

I don't have any __rcu_read_lock(). I guess this is against your
to-be-resent RCU patches?

> +DEFINE_PER_CPU(int, rcu_read_count);

Can have static scope.

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