From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 166C42C54 for ; Tue, 30 Oct 2018 11:19:01 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Oct 2018 03:19:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,444,1534834800"; d="scan'208";a="103733441" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.72]) ([10.237.220.72]) by fmsmga001.fm.intel.com with ESMTP; 30 Oct 2018 03:18:59 -0700 To: Alejandro Lucero , Thomas Monjalon Cc: lei.a.yao@intel.com, dev , "Xu, Qian Q" , xueqin.lin@intel.com, Ferruh Yigit References: <1538743527-8285-1-git-send-email-alejandro.lucero@netronome.com> <1593678.TTmrtHRuFR@xps> <2DBBFF226F7CF64BAFCA79B681719D954502B7E1@shsmsx102.ccr.corp.intel.com> <1651382.pnTT7vZl36@xps> From: "Burakov, Anatoly" Message-ID: Date: Tue, 30 Oct 2018 10:18:58 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v3 0/6] use IOVAs check based on DMA mask X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Oct 2018 10:19:02 -0000 On 29-Oct-18 11:39 AM, Alejandro Lucero wrote: > I got a patch that solves a bug when calling rte_eal_dma_mask using the > mask instead of the maskbits. However, this does not solves the deadlock. > > Interestingly, the problem looks like a compiler one. Calling > rte_memseg_walk does not return when calling inside rt_eal_dma_mask, but > if you modify the call like this: > > *diff --git a/lib/librte_eal/common/eal_common_memory.c > b/lib/librte_eal/common/eal_common_memory.c* > > *index 12dcedf5c..69b26e464 100644* > > *--- a/lib/librte_eal/common/eal_common_memory.c* > > *+++ b/lib/librte_eal/common/eal_common_memory.c* > > @@ -462,7 +462,7 @@rte_eal_check_dma_mask(uint8_t maskbits) > > /* create dma mask */ > > mask = ~((1ULL << maskbits) - 1); > > - if (rte_memseg_walk(check_iova, &mask)) > > +if (!rte_memseg_walk(check_iova, &mask)) > > /* > > * Dma mask precludes hugepage usage. > > * This device can not be used and we do not need to keep > > > it works, although the value returned to the invoker changes, of course. > But the point here is it should be the same behaviour when calling > rte_memseg_walk than before and it is not. > > > Anatoly, maybe you can see something I can not. > memseg walk will return 0 only when each callback returned 0 and there were no more segments left to call callbacks on. If your code always returns 0, then return value of memseg_walk will always be zero. If your code returns 1 or -1 in some cases, then this error condition will trigger. If it doesn't, then your condition by which you decide to return 1 or 0, is incorrect :) I couldn't spot any obvious issues there, but i'll recheck. -- Thanks, Anatoly