Linus Torvalds wrote: > On Mon, Oct 24, 2022 at 12:39 PM Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> wrote: > > > > I do think that the original locked page on migration problem was fixed > > by commit 9a1ea439b16b. Unfortunately the customer did not respond to > > us when we asked them to test their workload when that patch went > > into the mainline. > > Oh well. > > > I don't have objection to Matthew's fix to remove the bookmark code, > > now that it is causing problems with this scenario that I didn't > > anticipate in my original code. > > I'd really like to avoid *another* "we can't actually verify that this > helps" change in this area, so I'm hoping that the reporter that Dan > was talking to could test that patch. Oh, sorry, I had typed up that reply and contacted Tim offline, but forgot to send, now sent. > Otherwise we're kind of going back-and-forth based on "this might fix > things", which just feels really fragile and reminds me of the bad old > days when we had the "one step forward, two steps back" dance with > some of the suspend/resume issues. > > I realize that this code needs some extreme loads (and likely pretty > special hardware too) to actually become problematic, so testing is > _always_ going to be a bit of a problem, but still...