Re: zram corruption due to uninitialized do_swap_page fault

[Minchan Kim]

On Fri, Mar 18, 2022 at 10:32:07AM -0700, Minchan Kim wrote:
> On Fri, Mar 18, 2022 at 09:30:09AM -0700, Ivan Babrou wrote:
> > On Wed, Mar 16, 2022 at 11:26 AM Ivan Babrou <ivan@xxxxxxxxxxxxxx> wrote:
> > > I'm making an internal build and will push it to some location to see
> > > how it behaves, but it might take a few days to get any sort of
> > > confidence in the results (unless it breaks immediately).
> > >
> > > I've also pushed my patch that disables SWP_SYNCHRONOUS_IO to a few
> > > locations yesterday to see how it fares.
> > 
> > I have some updates before the weekend. There are two experimental groups:
> > 
> > * My patch that removes the SWP_SYNCHRONOUS_IO flag. There are 704
> > machines in this group across 5 datacenters with cumulative uptime of
> > 916 days.
> > * Minchan's patch to remove swap_slot_free_notify. There are 376
> > machines in this group across 3 datacenters with cumulative uptime of
> > 240 days.
> > 
> > Our machines take a couple of hours to start swapping anything after
> > boot, and I discounted these two hours from the cumulative uptime.
> > 
> > Neither of these two groups experienced unexpected coredumps or
> > rocksdb corruptions.
> > 
> > I think at this point it's reasonable to proceed with Minchan's patch
> > (including a backport).
> 
> Let me cook the patch and then will post it.
> 
> Thanks for the testing as well as reporting, Ivan!