上叫

Basically, there is only one upcall, with information as to what events caused it available from a pre_agreed mailbox. 基本上，只有一個回調(diào)，帶著來自一個預先設定的信箱信息，信息說明在什么事件發(fā)生時，線程可用。

The stack on which kse_init() is called must never be unwound, since the kernel fakes up a context at the point where kse_init() is called for each upcall. 調(diào)用kse_init()的堆棧永遠不能被釋放，因為在調(diào)用kse_init()的地方，內(nèi)核為每一個回調(diào)偽造了一個上下文。

I'll hang upcall you back, OK? 我先掛了，回頭再打給你，好嗎？