Subject: fsync optimization (Re: kern/25279: NFS read doesn't update atime)
To: None <chuq@chuq.com>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 06/29/2005 09:42:46
> currently, once a page is first faulted and the pmap-level mapping is created,
> it can be modified again indefinitely without the kernel knowing and thus
> without mtime being updated. if this is a problem, then we could change
> things so that making a clean page dirty again will cause another fault
> to give us a chance to update mtime again. we'll need that same refault-
> on-redirty logic to do the fsync() optimizations that were discussed
> some time back, so once we have that then we could also call back into
> the fs to update mtime if we want.
>
> -Chuck
have you decided to do fsync optimization in the way which needs
refault-on-redirty?
an alternative is not to care much about pages dirtied via mmap
as it isn't required by any standards afaik.
YAMAMOTO Takashi