linux-2.6.33/__lock_kernel() の履歴(No.1)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-2.6.33/__lock_kernel() へ行く。
  • 1 (2010-12-30 (木) 02:03:34)
  • 2 (2010-12-30 (木) 02:25:04)

---

参照元†

• linux-2.6.33/_lock_kernel()

説明†

• パス: linux-2.6.33/lib/kernel_lock.c

• FIXME: これは何？
  • 説明

引数†

• なし

返り値†

• なし

参考†

実装†

プリエンプション有効の場合†

/*
 * These are the BKL spinlocks - we try to be polite about preemption.
 * If SMP is not on (ie UP preemption), this all goes away because the
 * do_raw_spin_trylock() will always succeed.
 */
#ifdef CONFIG_PREEMPT

• • linux-2.6.33/CONFIG_PREEMPT

static inline void __lock_kernel(void)
{
	preempt_disable();

• • linux-2.6.33/preempt_disable()

	if (unlikely(!do_raw_spin_trylock(&kernel_flag))) {

• • linux-2.6.33/unlikely()

• linux-2.6.33/do_raw_spin_trylock()

• • linux-2.6.33/kernel_flag(global)

		/*
		 * If preemption was disabled even before this
		 * was called, there's nothing we can be polite
		 * about - just spin.
		 */
		if (preempt_count() > 1) {
			do_raw_spin_lock(&kernel_flag);
			return;

• • linux-2.6.33/preempt_count()

• linux-2.6.33/do_raw_spin_lock()

		}

		/*
		 * Otherwise, let's wait for the kernel lock
		 * with preemption enabled..
		 */
		do {
			preempt_enable();
			while (raw_spin_is_locked(&kernel_flag))
				cpu_relax();
			preempt_disable();

• • linux-2.6.33/preempt_enable()

• linux-2.6.33/raw_spin_is_locked()

• • linux-2.6.33/cpu_relax()

		} while (!do_raw_spin_trylock(&kernel_flag));
	}
}

プリエンプション無効の場合†

#else

/*
 * Non-preemption case - just get the spinlock
 */
static inline void __lock_kernel(void)
{
	do_raw_spin_lock(&kernel_flag);
}
#endif

コメント†