lkml.org 
[lkml]   [2007]   [Dec]   [20]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
FromNick Piggin <>
SubjectRe: [PATCH 10/28] FS-Cache: Recruit a couple of page flags for cache management [try #2]
DateFri, 21 Dec 2007 12:08:23 +1100
On Friday 21 December 2007 05:33, David Howells wrote:
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> > > > I'd much prefer if you would handle this in the filesystem, and have
> > > > it set PG_private whenever fscache needs to receive a callback, and
> > > > DTRT depending on whether PG_fscache etc. is set or not.> > >> > > That's tricky and slower[*].  One of the things I want to do is to
> > > modify iso9660 to do be able to do caching, but PG_private is 'owned'
> > > by the generic buffer cache code.> >> > Maybe it is harder, but it is the right way to do it.
>
> You're wrong.  It would mean that PG_private is the logical disjunction of
> PG_fscache and some condition not otherwise explicitly stored.  I tried
> that with NFS and it was nasty.
>
> As you can no doubt see, it means that you can't distinguish all the states
> you used to be able to.
>
> > So you should modify the filesystems rather than core code.
>
> I think you missed what I said:
>
> 	but PG_private is 'owned' by the generic buffer cache code.
>
> That means more of the core code would have to change - or, at least,
> change more.

Then make a PG_private2 bit and use that.



\
 
 \ /
  Last update: 2007-12-21 02:11    [from the cache]
©2003-2008