On Wed, May 11, 2022 at 12:03:13PM +0200, Wolfgang Walter wrote: > Hi, > > starting with 5.4.188 wie see a massive performance regression on our > nfs-server. It basically is serving requests very very slowly with cpu > utilization of 100% (with 5.4.187 and earlier it is 10%) so that it is > unusable as a fileserver. > > The culprit are commits (or one of it): > > c32f1041382a88b17da5736886da4a492353a1bb "nfsd: cleanup > nfsd_file_lru_dispose()" > 628adfa21815f74c04724abc85847f24b5dd1645 "nfsd: Containerise filecache > laundrette" > > (upstream 36ebbdb96b694dd9c6b25ad98f2bbd263d022b63 and > 9542e6a643fc69d528dfb3303f145719c61d3050) > > If I revert them in v5.4.192 the kernel works as before and performance is > ok again. > > I did not try to revert them one by one as any disruption of our nfs-server > is a severe problem for us and I'm not sure if they are related. > > 5.10 and 5.15 both always performed very badly on our nfs-server in a > similar way so we were stuck with 5.4. > > I now think this is because of 36ebbdb96b694dd9c6b25ad98f2bbd263d022b63 > and/or 9542e6a643fc69d528dfb3303f145719c61d3050 though I didn't tried to > revert them in 5.15 yet. Odds are 5.18-rc6 is also a problem? If so, I'll just wait for the fix to get into Linus's tree as this does not seem to be a stable-tree-only issue. thanks, greg k-h
