From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: Kevent POSIX timers support. Date: Tue, 28 Nov 2006 11:13:00 -0800 (PST) Message-ID: <20061128.111300.105813754.davem@davemloft.net> References: <456B3016.9020706@redhat.com> <20061127.104955.48519839.davem@davemloft.net> <20061128091602.GC15083@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: drepper@redhat.com, akpm@osdl.org, netdev@vger.kernel.org, zach.brown@oracle.com, hch@infradead.org, chase.venters@clientec.com, johann.borck@densedata.com, linux-kernel@vger.kernel.org, jeff@garzik.org, aviro@redhat.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:61891 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S936037AbWK1TMz (ORCPT ); Tue, 28 Nov 2006 14:12:55 -0500 To: johnpol@2ka.mipt.ru In-Reply-To: <20061128091602.GC15083@2ka.mipt.ru> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Evgeniy Polyakov Date: Tue, 28 Nov 2006 12:16:02 +0300 > Although ukevent has pointer embedded, it is unioned with u64, so there > should be no problems until 128 bit arch appeared, which likely will not > happen soon. There is also unused in kevent posix timers patch > 'u32 ret_val[2]' field, which can store segval's value too. > > But the fact that ukevent does not and will not in any way have variable > size is absolutely. I believe that in order to be %100 safe you will need to use the special aligned_u64 type, as that takes care of a crucial difference between x86 and x86_64 API, namely that u64 needs 8-byte alignment on x86_64 but not on x86. You probably know this already :-)