Re: page flags ?

[Chandra Seetharaman <sekharan@us.ibm.com>]

On Wed, May 18, 2005 at 05:09:29PM -0700, Badari Pulavarty wrote:
> On Wed, 2005-05-18 at 16:23, Andrew Morton wrote:
> > Badari Pulavarty <pbadari@us.ibm.com> wrote:
> > >
> > > Is it possible to get yet another PG_fs_specific flag ? 
> > 
> > Anything's possible ;)
> > 
> > How many bits are spare now?  ZONETABLE_PGSHIFT hurts my brain.
> 
> Depends on whom you ask :) CKRM folks are using one/few, 

CKRM used one bit... getting rid of it..

> Hotplug memory guys are using one... :( I lost track..
> 
> > 
> > > Reasons for it are:
> > > 
> > > 	- I need this for supporting delayed allocation on ext3.
> > 
> > Why?
> > 
> 
> I think, I explained you earlier.. But let me refresh your memory.
> 
> 
> In order to do delayed allocation, we "reserve" (not same reservation
> the code) a block in prepare/commit and do the allocation in
> writepage/writepages.  Unfortunately, mapped writes directly come into
> writepage without making a reservation. In order to guarantee that
> write() succeeds, I need a way to indicate if the "page" has made
> a reservation or not. I was hoping to use a page->flag to do this.
> That way I don't have to touch page->private like Alex's code and
> get away using mpage routines, instead of having my own.
> 
> 
> Thanks,
> Badari
> 
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>

-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan@us.ibm.com   |      .......you may get it.
----------------------------------------------------------------------
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>