From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: Re: [PATCH v3 net-next 5/7] rds: zerocopy Tx support. Date: Thu, 15 Feb 2018 15:42:23 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Sowmini Varadhan , Network Development , David Miller , rds-devel@oss.oracle.com To: Santosh Shilimkar Return-path: Received: from mail-ot0-f195.google.com ([74.125.82.195]:46957 "EHLO mail-ot0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161452AbeBOUnE (ORCPT ); Thu, 15 Feb 2018 15:43:04 -0500 Received: by mail-ot0-f195.google.com with SMTP id w10so914375ote.13 for ; Thu, 15 Feb 2018 12:43:04 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Feb 15, 2018 at 2:47 PM, Santosh Shilimkar wrote: > On 2/15/2018 10:49 AM, Sowmini Varadhan wrote: >> >> If the MSG_ZEROCOPY flag is specified with rds_sendmsg(), and, >> if the SO_ZEROCOPY socket option has been set on the PF_RDS socket, >> application pages sent down with rds_sendmsg() are pinned. >> >> The pinning uses the accounting infrastructure added by >> Commit a91dbff551a6 ("sock: ulimit on MSG_ZEROCOPY pages") >> >> The payload bytes in the message may not be modified for the >> duration that the message has been pinned. A multi-threaded >> application using this infrastructure may thus need to be notified >> about send-completion so that it can free/reuse the buffers >> passed to rds_sendmsg(). Notification of send-completion will >> identify each message-buffer by a cookie that the application >> must specify as ancillary data to rds_sendmsg(). >> The ancillary data in this case has cmsg_level == SOL_RDS >> and cmsg_type == RDS_CMSG_ZCOPY_COOKIE. >> >> Signed-off-by: Sowmini Varadhan >> --- > > > Acked-by: Santosh Shilimkar Acked-by: Willem de Bruijn