On Tue, Sep 02, 2025 at 05:27:11PM -0400, Mike Snitzer wrote: > On Tue, Sep 02, 2025 at 05:16:10PM -0400, Chuck Lever wrote: > > > > I am testing with a physically separate client and server, so I believe > > that LOCALIO is not in play. I do see WRITEs. And other workloads (in > > particular "fsx -Z <fname>") show READ traffic and I'm getting the > > new trace point to fire quite a bit, and it is showing misaligned > > READ requests. So it has something to do with dt. > > OK, yeah I figured you weren't doing loopback mount, only thing that > came to mind for you not seeing READ like expected. I haven't had any > problems with dt not driving READs to NFSD... > > You'll certainly need to see READs in order for NFSD's new misaligned > DIO READ handling to get tested. I was doing some additional testing of the v9 changes last night and realized why you weren't seeing any READs come through to NFSD: "flags=direct" must be added to the dt commandline. Otherwise it'll use buffered IO at the client and the READ will be serviced by the client's page cache. But like I said in another reply: when I just use v3 and RDMA (without the intermediary of flexfiles at the client) I'm not able to see the data mismatch with dt... So while its unlikely: does adding "flags=direct" cause dt to fail when NFSD handles the misaligned DIO READ? Mike
