Hi Oscar, On Tue, Sep 22, 2020 at 03:56:36PM +0200, Oscar Salvador wrote: > This patchset is the latest version of soft offline rework patchset > targetted for v5.9. > > This patchset fixes a couple of issues that the patchset Naoya > sent [1] contained due to rebasing problems and a misunterdansting. > > Main focus of this series is to stabilize soft offline. Historically soft > offlined pages have suffered from racy conditions because PageHWPoison is > used to a little too aggressively, which (directly or indirectly) invades > other mm code which cares little about hwpoison. This results in unexpected > behavior or kernel panic, which is very far from soft offline's "do not > disturb userspace or other kernel component" policy. > An example of this can be found here [2]. > > Along with several cleanups, this code refactors and changes the way soft > offline work. > Main point of this change set is to contain target page "via buddy allocator" > or in migrating path. > For ther former we first free the target page as we do for normal pages, and > once it has reached buddy and it has been taken off the freelists, we flag it > as HWpoison. > For the latter we never get to release the page in unmap_and_move, so > the page is under our control and we can handle it in hwpoison code. > > [1] https://patchwork.kernel.org/cover/11704083/ > [2] https://lore.kernel.org/linux-mm/20190826104144.GA7849@linux/T/#u FWIW, tested again with these patches in the ppc64 box and they work. I see that you added my Tested-by in the last patch but in any case: Tested-by: Aristeu Rozanski <aris@xxxxxxxxx> -- Aristeu
