修改内核路径

hc

2024-05-14 bedbef8ad3e75a304af6361af235302bcc61d06b

 kernel/include/linux/swait.h
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@@ -9,23 +9,10 @@
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 #include <asm/current.h>
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 /*
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- * BROKEN wait-queues.
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- *
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- * These "simple" wait-queues are broken garbage, and should never be
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- * used. The comments below claim that they are "similar" to regular
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- * wait-queues, but the semantics are actually completely different, and
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- * every single user we have ever had has been buggy (or pointless).
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- *
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- * A "swake_up_one()" only wakes up _one_ waiter, which is not at all what
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- * "wake_up()" does, and has led to problems. In other cases, it has
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- * been fine, because there's only ever one waiter (kvm), but in that
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- * case gthe whole "simple" wait-queue is just pointless to begin with,
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- * since there is no "queue". Use "wake_up_process()" with a direct
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- * pointer instead.
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- *
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- * While these are very similar to regular wait queues (wait.h) the most
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- * important difference is that the simple waitqueue allows for deterministic
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- * behaviour -- IOW it has strictly bounded IRQ and lock hold times.
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+ * Simple waitqueues are semantically very different to regular wait queues
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+ * (wait.h). The most important difference is that the simple waitqueue allows
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+ * for deterministic behaviour -- IOW it has strictly bounded IRQ and lock hold
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+ * times.
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  *
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  * Mainly, this is accomplished by two things. Firstly not allowing swake_up_all
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  * from IRQ disabled, and dropping the lock upon every wakeup, giving a higher
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@@ -39,7 +26,7 @@
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  *    sleeper state.
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  *
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  *  - the !exclusive mode; because that leads to O(n) wakeups, everything is
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- *    exclusive.
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+ *    exclusive. As such swake_up_one will only ever awake _one_ waiter.
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  *
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  *  - custom wake callback functions; because you cannot give any guarantees
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  *    about random code. This also allows swait to be used in RT, such that