hi, > Hello, > while working on nfs performance issues with overquota writes (which > turned out to be a ffs issue), I came up with the attached patch. > What this does it, for nfs over TCP, restrict a socket buffer processing > to a single thread (right now, all pending requests are processed > by all threads in parallel). This has two advantages: > - if a single client sends lots of request (like writes comming from a > linux client), a single thread is busy and other threads will be > available to serve other client's requests quickly > - by avoiding CPU cache sharing and lock contention at the vnode level > (if all requests are for the same vnode, which is the common case), > we get sighly better performances. > > My testbed is a linux box with 2 Opteron 2431 (12 core total) and 32GB RAM > writing over gigabit ethernet to a NetBSD server (dual > Intel(R) Xeon(TM) CPU 3.00GHz, 4 hyperthread cores total) running nfsd -tun4. > Without the patch, the server processes about 1230 writes per second, > with this patch it processes about 1250 writes/s. > > Comments ?
interesting. but doesn't it have ill effects if the client has multiple indepenedent activities on the mount point? YAMAMOTO Takashi > > -- > Manuel Bouyer <bou...@antioche.eu.org> > NetBSD: 26 ans d'experience feront toujours la difference > --
