From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 12AA7A0AC5 for ; Thu, 2 May 2019 15:03:48 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 16EC65F0F; Thu, 2 May 2019 15:03:47 +0200 (CEST) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id D803A5B26 for ; Thu, 2 May 2019 15:03:44 +0200 (CEST) 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; 02 May 2019 06:03:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,421,1549958400"; d="scan'208";a="169903696" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.113]) ([10.237.220.113]) by fmsmga001.fm.intel.com with ESMTP; 02 May 2019 06:03:42 -0700 To: "Carrillo, Erik G" , "rsanford@akamai.com" , "thomas@monjalon.net" Cc: "dev@dpdk.org" References: <1556737217-24338-1-git-send-email-erik.g.carrillo@intel.com> From: "Burakov, Anatoly" Message-ID: <7b2dfc9d-4638-f8ab-1f4b-ad268635b386@intel.com> Date: Thu, 2 May 2019 14:03:42 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH] timer: fix resource leak in finalize 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190502130342.PrPrAPR_ygEUyqZNYO7KFRIKNo9cjZzHkY5R1WCMa8o@z> On 02-May-19 1:19 PM, Carrillo, Erik G wrote: > > >> -----Original Message----- >> From: Burakov, Anatoly >> Sent: Thursday, May 2, 2019 4:18 AM >> To: Carrillo, Erik G ; rsanford@akamai.com; >> thomas@monjalon.net >> Cc: dev@dpdk.org >> Subject: Re: [dpdk-dev] [PATCH] timer: fix resource leak in finalize >> >> On 01-May-19 8:00 PM, Erik Gabriel Carrillo wrote: >>> The finalize function should free the memzone created in the init >>> function, rather than freeing the allocation the memzone references, >>> otherwise a memzone descriptor can be leaked. >>> >>> Fixes: c0749f7096c7 ("timer: allow management in shared memory") >>> >>> Signed-off-by: Erik Gabriel Carrillo >>> --- >>> lib/librte_timer/rte_timer.c | 12 ++++++++++-- >>> 1 file changed, 10 insertions(+), 2 deletions(-) >>> >>> diff --git a/lib/librte_timer/rte_timer.c >>> b/lib/librte_timer/rte_timer.c index eb46009..fb7a87e 100644 >>> --- a/lib/librte_timer/rte_timer.c >>> +++ b/lib/librte_timer/rte_timer.c >>> @@ -60,6 +60,7 @@ struct rte_timer_data { >>> }; >>> >>> #define RTE_MAX_DATA_ELS 64 >>> +static const struct rte_memzone *rte_timer_data_mz; >>> static struct rte_timer_data *rte_timer_data_arr; >>> static const uint32_t default_data_id; >>> static uint32_t rte_timer_subsystem_initialized; @@ -164,6 +165,7 @@ >>> rte_timer_subsystem_init_v1905(void) >>> if (mz == NULL) >>> return -EEXIST; >>> >>> + rte_timer_data_mz = mz; >>> rte_timer_data_arr = mz->addr; >>> >>> rte_timer_data_arr[default_data_id].internal_flags |= @@ - >> 180,6 >>> +182,7 @@ rte_timer_subsystem_init_v1905(void) >>> if (mz == NULL) >>> return -ENOMEM; >>> >>> + rte_timer_data_mz = mz; >>> rte_timer_data_arr = mz->addr; >>> >>> for (i = 0; i < RTE_MAX_DATA_ELS; i++) { @@ -205,8 +208,13 @@ >>> BIND_DEFAULT_SYMBOL(rte_timer_subsystem_init, _v1905, 19.05); >>> void __rte_experimental >>> rte_timer_subsystem_finalize(void) >>> { >>> - if (rte_timer_data_arr) >>> - rte_free(rte_timer_data_arr); >>> + if (rte_eal_process_type() != RTE_PROC_PRIMARY) >>> + return; >>> + >>> + if (!rte_timer_subsystem_initialized) >>> + return; >>> + >>> + rte_memzone_free(rte_timer_data_mz); >> >> The patch is a correct fix, but the whole idea of this looks dangerous to me. >> >> If we exit the primary while secondaries are still running, wouldn't it basically >> pull out timer data from under secondaries' feet? >> > > Ah yes - that’s right. Perhaps it would be better to maintain a reference count of some sort such that the last process to exit could cause the memzone_free. > It feels like a hack, to be honest. A process can crash or exit without calling rte_eal_cleanup(), which will lead to a memory leak due to refcount being stuck at a value that's not representing reality. It will be saf-er than current approach, but still not ideal. However, i guess it's a good compromise, if i were to choose between a memory leak and a segfault :D I wonder if there is a better approach. > Thanks, > Erik > >>> >>> rte_timer_subsystem_initialized = 0; >>> } >>> >> >> >> -- >> Thanks, >> Anatoly -- Thanks, Anatoly