From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [ethtool 1/1] ethtool: Add DMA Coalescing support Date: Fri, 25 Aug 2017 15:57:16 -0700 Message-ID: <20170825155716.630e6f72@xeon-e3> References: <20170825223910.54989-1-jeffrey.t.kirsher@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linville@tuxdriver.com, Paul Greenwalt , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com To: Jeff Kirsher Return-path: Received: from mail-pg0-f54.google.com ([74.125.83.54]:32953 "EHLO mail-pg0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964787AbdHYW5Y (ORCPT ); Fri, 25 Aug 2017 18:57:24 -0400 Received: by mail-pg0-f54.google.com with SMTP id t3so6093478pgt.0 for ; Fri, 25 Aug 2017 15:57:24 -0700 (PDT) In-Reply-To: <20170825223910.54989-1-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 25 Aug 2017 15:39:10 -0700 Jeff Kirsher wrote: > diff --git a/ethtool-copy.h b/ethtool-copy.h > index 06fc04c..4bb91eb 100644 > --- a/ethtool-copy.h > +++ b/ethtool-copy.h > @@ -400,6 +400,7 @@ struct ethtool_modinfo { > * a TX interrupt, when the packet rate is above @pkt_rate_high. > * @rate_sample_interval: How often to do adaptive coalescing packet rate > * sampling, measured in seconds. Must not be zero. > + * @dmac: How many usecs to store packets before moving to host memory. > * > * Each pair of (usecs, max_frames) fields specifies that interrupts > * should be coalesced until > @@ -450,6 +451,7 @@ struct ethtool_coalesce { > __u32 tx_coalesce_usecs_high; > __u32 tx_max_coalesced_frames_high; > __u32 rate_sample_interval; > + __u32 dmac; > }; > Because of backwards ABI compatibility, it is not safe to extend an existing structure.