Re: page flags ?
From: Badari Pulavarty <hidden>
Date: 2005-05-19 00:27:27
Also in:
linux-fsdevel
On Wed, 2005-05-18 at 16:23, Andrew Morton wrote:
Badari Pulavarty [off-list ref] wrote:quoted
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, Hotplug memory guys are using one... :( I lost track..
quoted
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>