Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ve0-f173.google.com ([209.85.128.173]:62673 "EHLO mail-ve0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758239AbaGAOVl (ORCPT ); Tue, 1 Jul 2014 10:21:41 -0400 Received: by mail-ve0-f173.google.com with SMTP id db11so9795002veb.32 for ; Tue, 01 Jul 2014 07:21:40 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20140701101034.520b04bb@tlielax.poochiereds.net> References: <1403810017-16062-1-git-send-email-jlayton@primarydata.com> <20140630125142.GA32089@infradead.org> <20140630085934.2bf86ba0@tlielax.poochiereds.net> <20140630193237.GA11935@fieldses.org> <20140630162014.20e63e1a@tlielax.poochiereds.net> <20140630163647.5227ac55@tlielax.poochiereds.net> <20140701101034.520b04bb@tlielax.poochiereds.net> Date: Tue, 1 Jul 2014 10:21:40 -0400 Message-ID: Subject: Re: [PATCH v2 000/117] nfsd: eliminate the client_mutex From: Trond Myklebust To: Jeff Layton Cc: "J. Bruce Fields" , Christoph Hellwig , Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Jul 1, 2014 at 10:10 AM, Jeff Layton wrote: > > Quite right. I changed the program to be run as root and had each child > process do an setfsuid/setfsgid to a different UID/GID combo: > > [jlayton@tlielax lockperf]$ time sudo ./opentest -n 128 -l 100 /mnt/rawhide/opentest > > real 0m3.448s > user 0m0.078s > sys 0m0.377s > [jlayton@tlielax lockperf]$ time sudo ./opentest -n 128 -l 100 /mnt/rawhide/opentest > > real 0m3.344s > user 0m0.053s > sys 0m0.374s > [jlayton@tlielax lockperf]$ time sudo ./opentest -n 128 -l 100 /mnt/rawhide/opentest > > real 0m3.550s > user 0m0.049s > sys 0m0.394s > > > ...so the speedup seems to be quite dramatic, actually -- 3x faster or > so with the patched kernel. > > The underlying filesystem is ext4 here, and the config is a rawhide > debug kernel config. For my next trick, I'll build some non-debug > kernels and replicate the test with them. Stay tuned... Just for grins, we should probably also try with the 3 client side OPEN parallelisation patches in my 'devel' branch. I'd expect them to give a slight performance improvement with your original test (i.e. the one that doesn't play the UID/GID games) Cheers Trond -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com