Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:45380 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752451Ab1KDIDp (ORCPT ); Fri, 4 Nov 2011 04:03:45 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pA483jJi016127 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 4 Nov 2011 04:03:45 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Message-ID: <20147.40030.333964.631999@regina.usersys.redhat.com> Date: Fri, 4 Nov 2011 19:03:42 +1100 From: Max Matveev To: Steve Dickson Cc: Linux NFS Mailing list Subject: Re: [PATCH 1/2] RDMA: RPCRDMA_MAX_DATA_SEGS cause i686 stack to blow. In-Reply-To: <1320346359-1515-1-git-send-email-steved@redhat.com> References: <1320346359-1515-1-git-send-email-steved@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 3 Nov 2011 14:52:38 -0400, Steve Dickson wrote: steved> Commit 2773395b3 increased RPCRDMA_MAX_DATA_SEGS from 8 steved> to 64 which significantly increases throughput with the steved> RDMA transport. steved> Unfortunately making RPCRDMA_MAX_DATA_SEGS that large blows steved> the stack on i686 builds during compilation. So the steved> RPCRDMA_MAX_PHYSREG_DATA_SEGS is used to allocated data on steved> the stack. How is it supposed to work if you "advertise" 256K r/wsize (64 * 4k) but only post enough buffers to deal with 64K worth of data? max