From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chuck Lever Subject: Re: [PATCH 12/14] SUNRPC: RPC buffer size estimates are too large Date: Thu, 18 Jan 2007 18:54:48 -0500 Message-ID: <45B008C8.6080601@oracle.com> References: <20070118232356.23310.6705.stgit@localhost.localdomain> <20070118233052.23310.25010.stgit@localhost.localdomain> <20070118234956.GC14242@fieldses.org> Reply-To: chuck.lever@oracle.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------060204090608040409020803" Cc: trond.myklybust@fys.uio.no, nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1H7h6p-0005hU-RN for nfs@lists.sourceforge.net; Thu, 18 Jan 2007 15:55:55 -0800 Received: from agminet01.oracle.com ([141.146.126.228]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1H7h6p-0002LL-Ew for nfs@lists.sourceforge.net; Thu, 18 Jan 2007 15:55:57 -0800 To: "J. Bruce Fields" In-Reply-To: <20070118234956.GC14242@fieldses.org> List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net This is a multi-part message in MIME format. --------------060204090608040409020803 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit J. Bruce Fields wrote: > On Thu, Jan 18, 2007 at 06:30:53PM -0500, Chuck Lever wrote: >> The RPC buffer size estimation logic in net/sunrpc/clnt.c always >> significantly overestimates the requirements for the buffer size. >> A little instrumentation demonstrated that in fact rpc_malloc was never >> allocating the buffer from the mempool, but almost always called kmalloc. >> >> To compute the size of the RPC buffer more precisely, split p_bufsiz into >> two fields; one for the argument size, and one for the result size. The >> goal is to keep the size requirement for RPC buffers at or below 2KiB. >> >> So now we will compute the sum of the exact call and reply header sizes, >> and split the RPC buffer precisely between the two. That should keep all >> RPCs within the 2KiB buffer mempool limit. >> >> And, we can finally be rid of RPC_SLACK_SPACE! > > I'm a little worried about krb5, and especially the integrity and > privacy code--I don't think this accounts for the space they need. > > I'm not sure how best to estimate their requirements.... If the RPC header field size definitions are correct, the verifiers are defined as 400 bytes (100 quads). There should be room enough for the largest verifiers. --------------060204090608040409020803 Content-Type: text/x-vcard; charset=utf-8; name="chuck.lever.vcf" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="chuck.lever.vcf" begin:vcard fn:Chuck Lever n:Lever;Chuck org:Oracle Corporation;Corporate Architecture Linux Projects Group email;internet:chuck dot lever at nospam oracle dot com title:Principle Member of Staff tel;work:+1 248 614 5091 x-mozilla-html:FALSE version:2.1 end:vcard --------------060204090608040409020803 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV --------------060204090608040409020803 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs --------------060204090608040409020803--