Trond Myklebust <[email protected]> wrote:
>
> On Wed, 2005-11-16 at 17:23 -0500, Trond Myklebust wrote:
> > On Wed, 2005-11-16 at 14:10 -0800, Andrew Morton wrote:
> >
> > > > How is the filesystem supposed to distinguish between the cases
> > > > "VM->writepage()", and "VM->writepages->mpage_writepages->writepage()"?
> > > >
> > >
> > > Via the writeback_control, hopefully.
> > >
> > > For write_one_page(), sync_mode==WB_SYNC_ALL, so NFS should start the I/O
> > > immediately (it appears to not do so).
> >
> > Sorry, but so does filemap_fdatawrite(). WB_SYNC_ALL clearly does not
> > discriminate between a writepages() and a single writepage() situation,
> > whatever the original intention was.
>
> IMHO, the correct way to distinguish between the two would be to use the
> wbc->nr_to_write field. If all the instances of writepage() were to set
> that field to '1', then the filesystems could do the right thing.
yes, except ->writepages is supposed to decrement nr_to_write as it proceeds,
so it'll end up at `1' by accident on the last go around the loop.
I think a separate boolean is better - it's just a single bit.
> As it is, you have shrink_list() that sets it to the value
> "SWAP_CLUSTER_MAX" for no apparent reason...
How weird. That's presumably wrong, but I'd need to check the changelogs
to doublecheck. ugh, 264 of them.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]