Re: [PATCH] Re: test10-pre7

Alexander Viro
2000-10-30T22:01:53Z

On Mon, 30 Oct 2000, Alexander Viro wrote:

>
>
> On Mon, 30 Oct 2000, Linus Torvalds wrote:
>
> > How about just changing ->sync_page() semantics to own the page lock? That
> > sound slike the right thing anyway, no?
>
> It would kill the ->sync_page(), but yes, _that_ might be the right thing ;-)

To elaborate: the thing is called if we get a contention on the page lock.
Essentially, its use in NFS is renice -20 for the requests on our page
wrt RPC scheduler. By the time when page gets unlocked it becomes a NOP.
On local filesystems it just runs the tq_disk - nothing in common with
the NFS case and IMO Trond was wrong lumping them together. In effect,
we are getting run_task_queue(&tq_disk) executed _very_ often and I'm less
than sure that it's a good idea. I think that ->sync_page() is not a
well-defined operation and NFS scheduler should use the locking of its own,
both for inavlidate_... and here.
Cheers,
Al