Re: [RFC 0/8] Cpuset aware writeback

[Andrew Morton <akpm@osdl.org>]

> On Wed, 17 Jan 2007 17:10:25 -0800 (PST) Christoph Lameter <clameter@sgi.com> wrote:
> On Wed, 17 Jan 2007, Andrew Morton wrote:
> 
> > > The inode lock is not taken when the page is dirtied.
> > 
> > The inode_lock is taken when the address_space's first page is dirtied.  It is
> > also taken when the address_space's last dirty page is cleaned.  So the place
> > where the inode is added to and removed from sb->s_dirty is, I think, exactly
> > the place where we want to attach and detach address_space.dirty_page_nodemask.
> 
> The problem there is that we do a GFP_ATOMIC allocation (no allocation 
> context) that may fail when the first page is dirtied. We must therefore 
> be able to subsequently allocate the nodemask_t in set_page_dirty(). 
> Otherwise the first failure will mean that there will never be a dirty 
> map for the inode/mapping.

True.  But it's pretty simple to change __mark_inode_dirty() to fix this.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/