From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 6AB5E6966 for ; Wed, 18 May 2016 10:06:55 +0200 (CEST) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga102.jf.intel.com with ESMTP; 18 May 2016 01:06:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,328,1459839600"; d="scan'208";a="105977478" Received: from smonroyx-mobl.ger.corp.intel.com (HELO [10.237.221.17]) ([10.237.221.17]) by fmsmga004.fm.intel.com with ESMTP; 18 May 2016 01:06:53 -0700 To: Thomas Monjalon , Jianfeng Tan References: <1457089092-4128-1-git-send-email-jianfeng.tan@intel.com> <1463013881-27985-1-git-send-email-jianfeng.tan@intel.com> <1671292.hQI6ccxuUZ@xps13> Cc: dev@dpdk.org, david.marchand@6wind.com, nhorman@tuxdriver.com From: Sergio Gonzalez Monroy Message-ID: <63ae23d7-7ca3-46e5-cfc1-1a6684395428@intel.com> Date: Wed, 18 May 2016 09:06:52 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <1671292.hQI6ccxuUZ@xps13> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v4] eal: make hugetlb initialization more robust X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 May 2016 08:06:55 -0000 On 17/05/2016 17:40, Thomas Monjalon wrote: > 2016-05-12 00:44, Jianfeng Tan: >> This patch adds an option, --huge-trybest, to use a recover mechanism to >> the case that there are not so many hugepages (declared in sysfs), which >> can be used. It relys on a mem access to fault-in hugepages, and if fails > relys -> relies > >> with SIGBUS, recover to previously saved stack environment with >> siglongjmp(). >> >> Besides, this solution fixes an issue when hugetlbfs is specified with an >> option of size. Currently DPDK does not respect the quota of a hugetblfs >> mount. It fails to init the EAL because it tries to map the number of free >> hugepages in the system rather than using the number specified in the quota >> for that mount. > It looks to be a bug. Why adding an option? > What is the benefit of the old behaviour, not using --try-best? I do not see any benefit to the old behavior. Given that we need the signal handling for the cgroup use case, I would be inclined to use this method as the default instead of trying to figure out how many hugepages we have free, etc. Thoughts? Sergio >> +static sigjmp_buf jmpenv; >> + >> +static void sigbus_handler(int signo __rte_unused) >> +{ >> + siglongjmp(jmpenv, 1); >> +} >> + >> +/* Put setjmp into a wrap method to avoid compiling error. Any non-volatile, >> + * non-static local variable in the stack frame calling sigsetjmp might be >> + * clobbered by a call to longjmp. >> + */ >> +static int wrap_sigsetjmp(void) >> +{ >> + return sigsetjmp(jmpenv, 1); >> +} > Please add the word "huge" to these variables and functions. > >> +static struct sigaction action_old; >> +static int need_recover; >> + >> +static void >> +register_sigbus(void) >> +{ >> + sigset_t mask; >> + struct sigaction action; >> + >> + sigemptyset(&mask); >> + sigaddset(&mask, SIGBUS); >> + action.sa_flags = 0; >> + action.sa_mask = mask; >> + action.sa_handler = sigbus_handler; >> + >> + need_recover = !sigaction(SIGBUS, &action, &action_old); >> +} >> + >> +static void >> +recover_sigbus(void) >> +{ >> + if (need_recover) { >> + sigaction(SIGBUS, &action_old, NULL); >> + need_recover = 0; >> + } >> +} > Idem, Please add the word "huge". >