On Tue, Sep 17, 2013 at 12:54:59PM +0000, Emmanuel Dreyfus wrote: > I have a NFS server that exhibit a high load (20-30) when supporting > about 30 clients, while there is no apparent bottleneck: low disck > activity, CPU idle most of the time, plenty of available RAM. > > Of course service is crapy, with many timouts. Any hint of what can be > going on?
I found the bottleneck. ps does not show it because it happens within the differen threads of nfsd. DDB tells me that almost all nfsd threads are waiting on tstile with this backtrace: turnstile_block rw_vector_enter genfs_lock VOP_LOCK vn_lock vget ufs_ihashget ffs_vget ufs_fhtovp VFS_FHTOVP nfsrv_fhtovp nfsrv_write nfssvc_nfsd sys_nfssvc -- Emmanuel Dreyfus m...@netbsd.org
