From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [take24 0/6] kevent: Generic event handling mechanism. Date: Mon, 20 Nov 2006 16:46:16 -0500 Message-ID: <45622228.80803@garzik.org> References: <11630606361046@2ka.mipt.ru> <45564EA5.6020607@redhat.com> <20061113105458.GA8182@2ka.mipt.ru> <4560F07B.10608@redhat.com> <20061120082500.GA25467@2ka.mipt.ru> <4562102B.5010503@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Evgeniy Polyakov , David Miller , Andrew Morton , netdev , Zach Brown , Christoph Hellwig , Chase Venters , Johann Borck , linux-kernel@vger.kernel.org, Alexander Viro Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:1962 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S966705AbWKTVq0 (ORCPT ); Mon, 20 Nov 2006 16:46:26 -0500 To: Ulrich Drepper In-Reply-To: <4562102B.5010503@redhat.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Ulrich Drepper wrote: > Evgeniy Polyakov wrote: >> It is exactly how previous ring buffer (in mapped area though) was >> implemented. > > Not any of those I saw. The one I looked at always started again at > index 0 to fill the ring buffer. I'll wait for the next implementation. I like the two-pointer ring buffer approach, one pointer for the consumer and one for the producer. > You don't want to have a channel like this. The userlevel code doesn't > know which threads are waiting in the kernel on the event queue. And it Agreed. > You are still completely focused on AIO. We are talking here about a > new generic event handling. It is not tied to AIO. We will add all Agreed. > As I said, relative timeouts are unable to cope with settimeofday calls > or ntp adjustments. AIO is certainly usable in situations where > timeouts are related to wall clock time. I think we have lived with relative timeouts for so long, it would be unusual to change now. select(2), poll(2), epoll_wait(2) all take relative timeouts. Jeff