From: Martin Knoblauch Subject: Re: [RFC][Resend] Make NFS-Client readahead tunable Date: Wed, 17 Sep 2008 09:10:49 -0700 (PDT) Message-ID: <766680.7905.qm@web32608.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-nfs list , linux-kernel@vger.kernel.org To: Jim Rees Return-path: Received: from web32608.mail.mud.yahoo.com ([68.142.207.235]:33615 "HELO web32608.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752352AbYIQQKu (ORCPT ); Wed, 17 Sep 2008 12:10:50 -0400 Sender: linux-nfs-owner@vger.kernel.org List-ID: Adding back LKML. ----- Original Message ---- > From: Jim Rees > To: Martin Knoblauch > Cc: linux-nfs list > Sent: Wednesday, September 17, 2008 5:31:12 PM > Subject: Re: [RFC][Resend] Make NFS-Client readahead tunable > > Martin Knoblauch wrote: > > We never needed that in our case. But yes, would be trivial. The question > is, whether there should be a maximum, just as a safeguard. > > Yes. The default should be (RPC_DEF_SLOT_TABLE - 1), and the maximum should > be max(xprt_udp_slot_table_entries, xprt_tcp_slot_table_entries) (maybe > minus one). > The default is NFS_MAX_READAHEAD, which is (RPC_DEF_SLOT_TABLE - 1). Incidentially, your suggested maximum seems to be the same on a default setup (minus one applied). > I wonder if it would make sense to adjust NFS_MAX_READAHEAD when > xprt_*_slot_table_entries is changed via sysctl. I am not sure how useful/practical this is, as currently the ra_factor is applied at mount time. Cheers Martin