RE: [PATCH V8 4/8] mm/fs: add hooks to support cleancache

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> From: Andrew Morton [mailto:akpm@xxxxxxxxxxxxxxxxxxxx]
> On Fri, 15 Apr 2011 07:47:57 -0700 (PDT) Dan Magenheimer
> <dan.magenheimer@xxxxxxxxxx> wrote:
> 
> > Hi Minchan --
> >
> > > Before I suggested a thing about cleancache_flush_page,
> > > cleancache_flush_inode.
> > >
> > > what's the meaning of flush's semantic?
> > > I thought it means invalidation.
> > > AFAIC, how about change flush with invalidate?
> >
> > I'm not sure the words "flush" and "invalidate" are defined
> > precisely or used consistently everywhere in computer
> > science, but I think that "invalidate" is to destroy
> > a "pointer" to some data, but not necessarily destroy the
> > data itself.   And "flush" means to actually remove
> > the data.  So one would "invalidate a mapping" but one
> > would "flush a cache".
> >
> > Since cleancache_flush_page and cleancache_flush_inode
> > semantically remove data from cleancache, I think flush
> > is a better name than invalidate.
> >
> > Does that make sense?
> 
> nope ;)
> 
> Kernel code freely uses "flush" to refer to both invalidation and to
> writeback, sometimes in confusing ways.  In this case,
> cleancache_flush_inode and cleancache_flush_page rather sound like they
> might write those things to backing store.

OK, I guess I am displaying my kernel-newbie-ness... though,
in this case, writeback of a cleancache page to backing store
doesn't make much sense either (since cleancache pages are
by definition "clean").

I'm happy to rename the hooks, though will probably not
repost a V9 unless/until more substantive changes collect...
unless someone considers this an unmergeable offense.

Thanks for the feedback, Minchan and Andrew!
Dan

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href


[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]