On October 8, 2026 11:25:13 PM GMT+02:00, Harry Yoo <[email protected]> wrote: >On Tue, Oct 06, 2026 at 02:20:26AM -0700, Kees Cook wrote: >> Hi! > >Hi Kees! > >Was hoping to say hi to you at LPC but I missed the chance ;) >Maybe next time. Safe travels! > >Uh, my mailbox stopped working for a few days as I forgot to renew >subscription. (Kiryl told me it's bouncing, thanks!) Hopefully I didn't >miss too much... > >> This gets the buckets able to handle memcg (GFP_KERNEL_ACCOUNT) with >> isolation (since it's common due to AF_UNIX), > >Cool! > >> and GFP_DMA with fall back >> (since it's rare). > >> It gave me an excuse to build out bucket kunit tests >> too, and that (and LLM review) found a couple other issues that needed >> fixing too, including msg_msg allocations going uncharged to their memcg >> when CONFIG_SLAB_BUCKETS=n (fixed in 2/8). > >Oh. > >> Harry, on your v4 question[1] about bucket users giving their own >> alignment: I tried that in v5, but a set's allocations don't always >> come from its own caches. With CONFIG_SLAB_BUCKETS=n, after a failed >> kmem_buckets_create(), and for the DMA and reclaimable fallbacks, they >> come from the general kmalloc caches, which can only give kmalloc()'s >> alignment. >> >> So v6 goes back to mirroring the kmalloc cache's alignment, > >I might be missing something, but why is that a problem? > >For kmem_buckets users, the reason* to specify alignment is because >they might need less strict alignment than kmalloc. > >(*Perhaps it's nice to document that in the comment) > >However, because kmem_buckets can fall back to kmalloc on e.g. kernels >w/o CONFIG_SLAB_BUCKETS, it should be fine to fall back. No? > >Creating kmem_buckets with more strict alignment than >kmalloc doesn't make sense. > >> and drops the ctor and flags arguments for the same reason. > >Uh, for ctor and flags, yes. We can't have them in kmem_buckets. > >> And the whole >> exploration made me realize I had a completely wrong understanding of >> how memcg worked. :P >> >> The bulk of this is mm/slab, but the final patch is netdev, which Paolo >> acked in v4, so I'm hoping this whole series can go via slab? > >Going thorough slab/for-next sounds reasonable to me once it gets >some reviews. > >Vlastimil?
Sure! If you review and feel it's ready to be added there, please do so. I couldn't yet due to conferencing, should be able next week.
