Re: [PATCH] Remove argument from open_softirq which is always NULL

[Ingo Molnar <mingo@elte.hu>]

* Carlos R. Mafra <crmafra2@gmail.com> wrote:

> Subject: [PATCH] Remove argument from open_softirq which is always 
> NULL
> 
> As git-grep shows, open_softirq() is always called with the last 
> argument being NULL
> 
> block/blk-core.c:       open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL);
> kernel/hrtimer.c:       open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
> kernel/rcuclassic.c:    open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
> kernel/rcupreempt.c:    open_softirq(RCU_SOFTIRQ, rcu_process_callbacks, NULL);
> kernel/sched.c: open_softirq(SCHED_SOFTIRQ, run_rebalance_domains, NULL);
> kernel/softirq.c:       open_softirq(TASKLET_SOFTIRQ, tasklet_action, NULL);
> kernel/softirq.c:       open_softirq(HI_SOFTIRQ, tasklet_hi_action, NULL);
> kernel/timer.c: open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL);
> net/core/dev.c: open_softirq(NET_TX_SOFTIRQ, net_tx_action, NULL);
> net/core/dev.c: open_softirq(NET_RX_SOFTIRQ, net_rx_action, NULL);
> 
> This observation has already been made by Matthew Wilcox in June 2002
> (http://www.cs.helsinki.fi/linux/linux-kernel/2002-25/0687.html)
> 
> "I notice that none of the current softirq routines use the data element
> passed to them."
> 
> and the situation hasn't changed since them. So it appears we can 
> safely remove that extra argument to save 128 (54) bytes of kernel 
> data (text).

applied to -tip, thanks Carlos. Nice find!

	Ingo