On 4/7/19 10:00 AM, Christoph Hellwig wrote: > On Fri, Apr 05, 2019 at 07:11:17PM +0200, Vlastimil Babka wrote: >> On 3/22/19 6:52 PM, Christopher Lameter wrote: >> > On Thu, 21 Mar 2019, Vlastimil Babka wrote: >> > >> >> That however doesn't work well for the xfs/IO case where block sizes are >> >> not known in advance: >> >> >> >> https://lore.kernel.org/linux-fsdevel/20190225040904.5557-1-ming.lei@xxxxxxxxxx/T/#ec3a292c358d05a6b29cc4a9ce3ae6b2faf31a23f >> > >> > I thought we agreed to use custom slab caches for that? >> >> Hm maybe I missed something but my impression was that xfs/IO folks would have >> to create lots of them for various sizes not known in advance, and that it >> wasn't practical and would welcome if kmalloc just guaranteed the alignment. >> But so far they haven't chimed in here in this thread, so I guess I'm wrong. > > Yes, in XFS we might have quite a few. Never mind all the other > block level consumers that might have similar reasonable expectations > but haven't triggered the problematic drivers yet. What about a LSF session/BoF to sort this out, then? Would need to have people from all three MM+FS+IO groups, I suppose.