Re: [PATCH v39 16/24] x86/sgx: Add a page reclaimer

[Jarkko Sakkinen]

On Mon, Oct 05, 2020 at 01:39:21AM +0300, Jarkko Sakkinen wrote:
> On Sat, Oct 03, 2020 at 01:23:49PM -0500, Haitao Huang wrote:
> > On Sat, 03 Oct 2020 08:32:45 -0500, Jarkko Sakkinen
> > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
> > 
> > > On Sat, Oct 03, 2020 at 12:22:47AM -0500, Haitao Huang wrote:
> > > > When I turn on CONFIG_PROVE_LOCKING, kernel reports following
> > > > suspicious RCU
> > > > usages. Not sure if it is an issue. Just reporting here:
> > > 
> > > I'm glad to hear that my tip helped you to get us the data.
> > > 
> > > This does not look like an issue in the page reclaimer, which was not
> > > obvious for me before. That's a good thing. I was really worried about
> > > that because it has been very stable for a long period now. The last
> > > bug fix for the reclaimer was done in June in v31 version of the patch
> > > set and after that it has been unchanged (except possibly some renames
> > > requested by Boris).
> > > 
> > > I wildly guess I have a bad usage pattern for xarray. I migrated to it
> > > in v36, and it is entirely possible that I've misused it. It was the
> > > first time that I ever used it. Before xarray we had radix_tree but
> > > based Matthew Wilcox feedback I did a migration to xarray.
> > > 
> > > What I'd ask you to do next is to, if by any means possible, to try to
> > > run the same test with v35 so we can verify this. That one still has
> > > the radix tree.
> > > 
> > 
> > 
> > v35 does not cause any such warning messages from kernel
> 
> Thank you. Looks like Matthew already located the issue, a fix will
> land soon.

Just acknowledging that this should be fixed in my master branch now.

/Jarkko