lkml.org 
[lkml]   [2006]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH 05/19] NFS: Use local caching
From
Date
On Wed, 2006-11-15 at 16:00 +0000, David Howells wrote:
> Trond Myklebust <trond.myklebust@fys.uio.no> wrote:
>
> > Why is fscache being given a vote on whether or not the NFS page can be
> > removed from the mapping? If the file has changed on the server, so that
> > we have to invalidate the mapping, then I don't care about the fact that
> > fscache is busy: the page has to go.
>
> This is releasepage() not invalidatepage(). It is conditional.

...and invalidate_complete_page2() calls try_to_release_page() which
again calls releasepage(). Success or failure of the latter should
therefore not depend on the internal fscache state.

> > > @@ -942,11 +954,13 @@ static int nfs_update_inode(struct inode
> > > ...
> > > + nfs_fscache_set_size(inode);
> >
> > Doesn't nfs_fscache_set_size try to grab rw_semaphores? This function is
> > _always_ called with the inode->i_lock spinlock held.
>
> Hmmm... I wonder if I need to do this in nfs_update_inode() at all. Won't the
> pages and the cache object attached to an inode be discarded anyway if the file
> attributes returned by the server change?

In the case of a read-only file, yes. That is not true of a read/write
file.

> > > static void nfs_readpage_release(struct nfs_page *req)
> > > {
> > > + struct inode *d_inode = req->wb_context->dentry->d_inode;
> > > +
> > > + if (PageUptodate(req->wb_page))
> > > + nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
> > > +
> >
> > Will usually be called from an rpciod context. Should therefore not be
> > grabbing semaphores, doing memory allocation etc.
>
> Is it possible to make an NFS kernel thread that can have completed nfs_page
> structs queued for writing to the cache?

Why should we add extra context switches for the non-fscache case? Just
move the call to nfs_readpage_to_fscache into its own kernel thread.

Trond

-
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/

\
 
 \ /
  Last update: 2006-11-15 17:57    [W:0.661 / U:1.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site