From mboxrd@z Thu Jan 1 00:00:00 1970 From: jianhai luan Subject: Re: DomU's network interface will hung when Dom0 running 32bit Date: Tue, 15 Oct 2013 22:29:15 +0800 Message-ID: <525D513B.70406@oracle.com> References: <52590DFE.6080203@oracle.com> <20131014111958.GE11739@zion.uk.xensource.com> <525CAC21.5040202@oracle.com> <1381826609.24708.135.camel@kazak.uk.xensource.com> <525D0C41.2080407@oracle.com> <20131015100624.GB29436@zion.uk.xensource.com> <525D2667.6040102@oracle.com> <20131015125802.GR11739@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Ian Campbell , xen-devel@lists.xenproject.org, netdev@vger.kernel.org, ANNIE LI To: Wei Liu Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:31246 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932524Ab3JOO32 (ORCPT ); Tue, 15 Oct 2013 10:29:28 -0400 In-Reply-To: <20131015125802.GR11739@zion.uk.xensource.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2013-10-15 20:58, Wei Liu wrote: > On Tue, Oct 15, 2013 at 07:26:31PM +0800, jianhai luan wrote: > [...] >>>>> Can you propose a patch? >>>> Because credit_timeout.expire always after jiffies, i judge the >>>> value over the range of time_after_eq() by time_before(now, >>>> vif->credit_timeout.expires). please check the patch. >>> I don't think this really fix the issue for you. You still have chance >>> that now wraps around and falls between expires and next_credit. In that >>> case it's stalled again. >> if time_before(now, vif->credit_timeout.expires) is true, time wrap >> and do operation. Otherwise time_before(now, >> vif->credit_timeout.expires) isn't true, now - >> vif->credit_timeout.expires should be letter than ULONG_MAX/2. >> Because next_credit large than vif->credit_timeout.expires >> (next_crdit = vif->credit_timeout.expires + >> msecs_to_jiffies(vif->credit_usec/1000)), the delta between now and >> next_credit should be in range of time_after_eq(). So >> time_after_eq() do correctly judge. >> > Not sure I understand you. Consider "now" is placed like this: > > expires now next_credit > ----time increases this direction---> > > * time_after_eq(now, next_credit) -> false > * time_before(now, expires) -> false If now is placed in above environment, the result will be correct (Sending package will be not allowed until next_credit). * time_after_eq(now, next_credit) --> false will include two environment: expires now next_credit -----------time increases this direction ----> Or expires next_credit next_credit + MAX_LONG/2 now -----------time increases this direction ----> the first environment should be correct to control transmit. the second environment is our included environment. Jason > > Then it's stuck again. You're merely narrowing the window, not fixing > the real problem. > > Wei. > >> Jason >>> Wei.