Hey, Den 2026-03-23 kl. 18:37, skrev Thadeu Lima de Souza Cascardo: > On Mon, Mar 23, 2026 at 05:46:28PM +0100, Maarten Lankhorst wrote: >> Hey, >> >> >> Den 2026-03-21 kl. 20:27, skrev Tejun Heo: >>> Hello, >>> >>> Generally looks okay to me. One comment on 3/3 — the naked xchg() in >>> set_resource_max() needs a comment explaining why it's used instead of >>> page_counter_set_max() and what the semantics are (unconditionally sets max >>> regardless of current usage to prevent further allocations, since there's no >>> eviction mechanism yet). >>> >>> Applied 1/3. Maarten, Michal, what do you think? >> >> Yeah probably drop 2/3 too since there is no longer a case where setting a >> limit may fail. >> >> Kind regards, >> ~Maarten Lankhorst > > Actually, this can still happen if an invalid region name is given. > > So, one could write: > > echo -e 'region1 max\ninvalidregion2 max\n' > dmem.max > > And even though setting the value for region1 would be applied, the write > would return -EINVAL.
Makes sense. It would be good to validate in advance then. If that's not possible we should at least not error when we try to update 2 regions simultaneously. Likely the best to do so anyway if we want to handle eviction, which may be handled in a blocking fashion. Kind regards, ~Maarten Lankhorst
