From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: [PATCH] TX_RING and packet mmap Date: Tue, 21 Apr 2009 17:00:52 -0400 (EDT) Message-ID: References: <1238701718.5669.26.camel@bender> <7e0dd21a0904211313p73143cc8t51b5c537c5edfb05@mail.gmail.com> <7e0dd21a0904211400l3c9e78e9v70b684702eef89d5@mail.gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: netdev@vger.kernel.org To: Johann Baudy Return-path: Received: from smtp.ultrahosting.com ([74.213.174.254]:45310 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754378AbZDUVIz (ORCPT ); Tue, 21 Apr 2009 17:08:55 -0400 Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id E096982C453 for ; Tue, 21 Apr 2009 17:19:19 -0400 (EDT) Received: from smtp.ultrahosting.com ([74.213.174.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id MtsD600yxQz0 for ; Tue, 21 Apr 2009 17:19:13 -0400 (EDT) Received: from qirst.com (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id CAD9382C280 for ; Tue, 21 Apr 2009 17:19:13 -0400 (EDT) In-Reply-To: <7e0dd21a0904211400l3c9e78e9v70b684702eef89d5@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 21 Apr 2009, Johann Baudy wrote: > > Duh. So I cannot concurrently operate with multiple threads on the > > structure. > Except if you can ensure that multiple threads will not use the same buffer. Hmmm... Ok. > > The kernel synchronizes with itself via the socket? > Not sure to understand? Doesnt the kernel need some way to synchronize the two transitions made by the kernel? From "send request" to "sending" and then to "available"? Otherwise the kernel may set the request to "available" before the change from "send request" to "sending" is complete.