Re: [PATCH 2.6.20-rc3] TTY_IO code cleanups

From: Jan Engelhardt
Date: Sat Jan 06 2007 - 09:40:38 EST



On Jan 5 2007 16:00, David Rientjes wrote:
>> @@ -791,17 +790,15 @@ static int tty_ldisc_try(struct tty_struct *tty)
>> {
>> unsigned long flags;
>> struct tty_ldisc *ld;
>> - int ret = 0;
>>
>> spin_lock_irqsave(&tty_ldisc_lock, flags);
>> ld = &tty->ldisc;
>> - if(test_bit(TTY_LDISC, &tty->flags))
>> - {
>> + if(test_bit(TTY_LDISC, &tty->flags)) {
>> ld->refcount++;
>> - ret = 1;
>> + return 1;
>> }
>> spin_unlock_irqrestore(&tty_ldisc_lock, flags);
>> - return ret;
>> + return 0;
>> }
>>
>> /**
>
>You leave tty_ldisk_lock locked.

Hence it was not redundant. Either way,

if(test_bit(...)) {
spin_unlock_irqrestore(..)
return 1;
}

would probably generate the same ASM as the original, hence it is not
really an improvement.


-`J'
--
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