On Fri, Jul 3, 2020 at 1:30 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote: > On Fri 03-07-20 10:34:09, Catangiu, Adrian Costin wrote: > > This patch adds logic to the kernel power code to zero out contents of > > all MADV_WIPEONSUSPEND VMAs present in the system during its transition > > to any suspend state equal or greater/deeper than Suspend-to-memory, > > known as S3. > > How does the application learn that its memory got wiped? S2disk is an > async operation and it can happen at any time during the task execution. > So how does the application work to prevent from corrupted state - e.g. > when suspended between two memory loads? You can do it seqlock-style, kind of - you reserve the first byte of the page or so as a "is this page initialized" marker, and after every read from the page, you do a compiler barrier and check whether that byte has been cleared.
