search for: lets_redo_it

On Fri 03-07-20 15:29:22, Jann Horn wrote: > On Fri, Jul 3, 2020 at 1:30 PM Michal Hocko <mhocko at kernel.org> 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

On Fri 03-07-20 15:29:22, Jann Horn wrote: > On Fri, Jul 3, 2020 at 1:30 PM Michal Hocko <mhocko at kernel.org> 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

...al is to have cryprographically-safe get_random_number() with 0 > syscalls. > > You'd need to do: > > if (!poll(did_i_migrate)) { > use_prng_seed(); > if (poll(did_i_migrate)) { > /* oops_they_migrated_me_in_middle_of_computation, > lets_redo_it() */ > goto retry: > } > } > > Which means two syscalls.. Is this a real problem though? Do we have any actual numbers? E.g. how often does the migration happen so that 2 syscalls would be visible in actual workloads? -- Michal Hocko SUSE Labs

...al is to have cryprographically-safe get_random_number() with 0 > syscalls. > > You'd need to do: > > if (!poll(did_i_migrate)) { > use_prng_seed(); > if (poll(did_i_migrate)) { > /* oops_they_migrated_me_in_middle_of_computation, > lets_redo_it() */ > goto retry: > } > } > > Which means two syscalls.. Is this a real problem though? Do we have any actual numbers? E.g. how often does the migration happen so that 2 syscalls would be visible in actual workloads? -- Michal Hocko SUSE Labs

...ing mechanism like poll on a fd. That The goal is to have cryprographically-safe get_random_number() with 0 syscalls. You'd need to do: if (!poll(did_i_migrate)) { use_prng_seed(); if (poll(did_i_migrate)) { /* oops_they_migrated_me_in_middle_of_computation, lets_redo_it() */ goto retry: } } Which means two syscalls.. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubb...