Messages in this thread | | | Date | Fri, 04 Jan 2002 15:07:20 -0800 | From | Andrew Morton <> | Subject | Re: hashed waitqueues |
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William Lee Irwin III wrote: > > This is a long-discussed space optimization for the VM system, with > what is expected to be a minor time tradeoff.
Nice code.
> ... > + /* > + * Although the default semantics of wake_up() are > + * to wake all, here the specific function is used > + * to make it even more explicit that a number of > + * pages are being waited on here. > + */ > + if(waitqueue_active(page_waitqueue(page))) > + wake_up_all(page_waitqueue(page));
Does the compiler CSE these two calls to page_waitqueue()? All versions? I'd be inclined to do CSE-by-hand here.
Also, why wake_up_all()? That will wake all tasks which are sleeping in __lock_page(), even though they've asked for exclusive wakeup semantics. Will a bare wake_up() here not suffice?
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