On Mon, May 31, 2021 at 12:59:51PM +0800, Wang Yugui wrote: > > > Hi, > > nfsd dead loop when xfstests generic/531 > > linux kernel of nfs server: 5.10.41 > linux kernel of nfs client: 5.10.41 > > > nfsd dead loop when xfstests generic/531 > > linux kernel of nfs server: 5.10.41 > linux kernel of nfs client: 5.10.41 This is a known issue. generic/531 opens a large number of files, causing the nfsd file cache code to walk a very long LRU list of open files. For v4, there will be a lot of long term opens (because of the OPEN call), and they all end up on that list. So, the basic issue is, that the nfsd file cache is a good match for v3 semantics, but less so for v4 semantics. I posted an experimental patch to work around the issue: https://lore.kernel.org/linux-nfs/20201020183718.14618-4-trondmy@xxxxxxxxxx/T/#m869aa427f125afee2af9a89d569c6b98e12e516f The rhashtable patch has issues, so disregard that one, but the other one is a basic fix for this issue. It has one other issue that I noticed (refcount error), but that is easily fixed. I should update the patch and formally post it.. - Frank
