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    SubjectRe: [PATCH 2.4.0-test8] mm/filemap.c
    Also sprach David Mansfield:
    } Bill Wendling wrote:
    } >
    } > Hi Linus,
    } >
    } > Here's a small optimization for the mm/filemap.c file.
    } >
    } > - The `head = &mapping->pages;' statement is useless inside the
    } > repeat, since head isn't modified inside the loop.
    } > - The `curr = curr->next;' statement doesn't need to be executed
    } > if the repeat is taken. I changed the while() into a for() loop
    } > to accomodate this better.
    } >
    } I spotted the curr = curr->next thing yesterday, too! I think you're
    } right on that one. But I'm not sure about the head = &mapping thing.
    } The reason we jump back here is that we've been outside the spinlock'ed
    } critical section. Is it possible for the &mapping->pages to change
    } during this period of time (when spinlock isn't held?), if not, your
    } patch is ok. If it could change, we need to re-initialize head because
    } it could have changed while we didn't have the lock locked.
    Doh...Yeah. But...Shouldn't the `head = &mapping->pages;' thing be inside
    of a spinlock if &mapping->pages could change? Say it changed between the
    assignment and the function grabbing the lock?

    Does anyone else know better on this?

    || Bill Wendling
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