Hey, On 6/8/26 14:42, Maxime Ripard wrote: > On Sat, Jun 06, 2026 at 11:44:10PM +0200, Maarten Lankhorst wrote: >> Hey, >> >> On 6/6/26 18:31, Natalie Vock wrote: >>> On 6/6/26 00:44, Eric Chanudet wrote: >>>> Accept only one "region value" pair entry for the dmem.max, dmem.min, >>>> dmem.low files.> >>>> This changes the UAPI that otherwise accepted multiple lines for setting >>>> multiple entries in one write. No existing user is known to rely on >>>> writing multiple regions in a single write. >>> >>> Ugh, shoot. >>> >>> For dmem.low specifically, there already are some userspace thingies >>> floating around that may write more than one region/value pairs. >>> >>> These thingies all depend on that one patchset for dmemcg protection that I >>> should really get around to merging[1]. Since the userspace utilities >>> depend on not-yet-merged patches, they sort of have to expect stuff >>> changing under their belts, so I wouldn't really consider those users a >>> blocker by necessity. >>> >>> As I see it, we could go down one of two paths: >>> 1. We go ahead with the patch as proposed, and I make sure that the users I >>> know of adapt. Could be a bit icky wrt. "do not break userspace" rules, but >>> since the already use non-merged UAPIs in one place, you can argue that >>> these users kind of have to expect breakage. >>> 2. We use the old handling allowing multiple lines for dmem.min and >>> dmem.low only. This preserves compatibility but uglifies the code by quite >>> a bit. >>> >>> All things considered, I think I personally would prefer going with 1. and >>> taking the patch as proposed and just having one codepath handling every >>> limit file. Just highlighting this so we don't do it on accident. >>> >>> [1] https://patchwork.freedesktop.org/series/163183/ >>> >> >> I prefer option 1 as well, but would like an ack from one of the core cgroup >> maintainers too, >> and what Maxime's opinion on this as well. > > Option 1 works for me too if doable > > Maxime
I see this as an acked-by? I'll commit this patch to drm-misc-next if so. Fortunately it may not even break those scripts in the typical case where only 1 region is registered, eg the most common laptop/desktop case. Kind regards, ~Maarten Lankhorst
