Return-Path: Received: from quartz.orcorp.ca ([184.70.90.242]:42609 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753286AbdIEUGO (ORCPT ); Tue, 5 Sep 2017 16:06:14 -0400 Date: Tue, 5 Sep 2017 14:06:08 -0600 From: Jason Gunthorpe To: Chuck Lever Cc: sagi@grimberg.me, linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH RFC 0/5] xprtrdma Send completion batching Message-ID: <20170905200608.GA4055@obsidianresearch.com> References: <20170905164347.11106.27140.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170905164347.11106.27140.stgit@manet.1015granger.net> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Sep 05, 2017 at 01:00:10PM -0400, Chuck Lever wrote: > - Send completions are batched to reduce interrupts, but still > provide a periodic heartbeat signal for SQ housekeeping I would scrub this commentary, it is very misleading. The idea of a periodic completion does not match how verbs works at all, it was an incomplete root cause analysis from a HCA that uses different rules for freeing space in the SQ. Instead, I would say this series creates strong SQ accounting and properly guarentees the SQ can never overflow by only releasing SQ's back into the pool when the HCA has confirmed they are completed via a CQ. Jason