2022-06-01 17:40 GMT+09:00, David Howells <dhowells@xxxxxxxxxx>: > Namjae Jeon <linkinjeon@xxxxxxxxxx> wrote: > >> Okay, How do you reproduce this problem ? Did you run xfsftests >> against ksmbd RDMA ? > > Yeah - I've been making sure my cifs filesystem changes work with RDMA. > There've been a lot of connections that haven't been taken down cleanly, > due > to oopses, lockups and stuff. > > One thing that could be useful is, say, /proc/fs/ksmbd/ > >> Okay, we need to add maximum retry count for that case. >> but when I check kernel thread name in your top message, It is RDMA >> connection. >> So smb_direct_read() is used in ksmbd_conn_handler_loop(). >> I'd like to reproduce the problem to figure out where the problem is. >> Can I try to reproduce it with soft-iWARP and xfstests? > > Note that I only noticed the issue when I switched to working on another > filesystem and found that performance was unexpectedly down by 80%. > > I was using softRoCE, though it may well be causable with softIWarp also, > since that's not really a detail visible to cifs/ksmbd, I think. > > I've just had a quick go at trying to reproduce this, hard-resetting the > test > client in the middle of performing an xfstest run, but it didn't seem to > cause > the single ksmbd:r5445 thread to explode. Thanks for your check! We also try to reproduce it but can't reproduce it yet. Let's check whether an infinite loop can occur in smb_direct_read(). > > David > >
