From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nagendra Tomar Subject: Re: [PATCH 2.6.23-rc6 Resending] NETWORKING : Edge Triggered EPOLLOUT events get missed for TCP sockets Date: Thu, 20 Sep 2007 15:58:57 -0700 (PDT) Message-ID: <798693.92196.qm@web53705.mail.re2.yahoo.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: netdev@vger.kernel.org, Linux Kernel Mailing List , David Miller To: Davide Libenzi Return-path: Received: from web53705.mail.re2.yahoo.com ([206.190.37.26]:46229 "HELO web53705.mail.re2.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751049AbXITW66 (ORCPT ); Thu, 20 Sep 2007 18:58:58 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org --- Davide Libenzi wrote: > That's not what POLLOUT means in the Unix meaning. POLLOUT indicates the > ability to write, and it is not meant as to signal every time a packet > (skb) is sent on the wire (and the buffer released). Aren't they both the same ? Everytime an incoming ACK frees up a buffer from the retransmit queue, the writability condition is freshly asserted, much the same way as the readability condition is asserted everytime a new data is queued in the socket receive queue (irrespective of whether there was data already waiting to be read in the receive queue). This difference in meaning of POLLOUT only arises in the ET case, which was not what traditional Unix poll referred to. Since its a new game the rules can be modified (ofcourse based on the merits i.e. usability) Thanx, Tomar ___________________________________________________________ Want ideas for reducing your carbon footprint? Visit Yahoo! For Good http://uk.promotions.yahoo.com/forgood/environment.html