Re: [PATCH v3] rcu: Deinline rcu_read_lock_sched_held() if DEBUG_LOCK_ALLOC

[Steven Rostedt]

On Tue, 26 May 2015 17:48:34 +0200
Denys Vlasenko <dvlasenk@xxxxxxxxxx> wrote:

> DEBUG_LOCK_ALLOC=y is not a production setting, but it is
> not very unusual either. Many developers routinely
> use kernels built with it enabled.
> 
> Apart from being selected by hand, it is also auto-selected by
> PROVE_LOCKING "Lock debugging: prove locking correctness" and
> LOCK_STAT "Lock usage statistics" config options.
> LOCK STAT is necessary for "perf lock" to work.
> 
> I wouldn't spend too much time optimizing it, but this particular
> function has a very large cost in code size: when it is deinlined,
> code size decreases by 830,000 bytes:
> 
>     text     data      bss       dec     hex filename
> 85674192 22294776 20627456 128596424 7aa39c8 vmlinux.before
> 84837612 22294424 20627456 127759492 79d7484 vmlinux
> 
> (with this config: http://busybox.net/~vda/kernel_config)
> 
> Signed-off-by: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
> CC: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
> CC: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> CC: Steven Rostedt <rostedt@xxxxxxxxxxx>
> CC: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> CC: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
> CC: Tejun Heo <tj@xxxxxxxxxx>
> CC: Oleg Nesterov <oleg@xxxxxxxxxx>
> CC: linux-kernel@xxxxxxxxxxxxxxx

Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/