From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 503F4A0613 for ; Mon, 26 Aug 2019 22:44:29 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 3EA3F1C0B3; Mon, 26 Aug 2019 22:44:28 +0200 (CEST) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 780EE1C0B2 for ; Mon, 26 Aug 2019 22:44:26 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Aug 2019 13:44:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,433,1559545200"; d="scan'208";a="187708372" Received: from jrharri1-skx.ch.intel.com (HELO [127.0.1.1]) ([143.182.137.73]) by FMSMGA003.fm.intel.com with ESMTP; 26 Aug 2019 13:44:25 -0700 From: Jim Harris To: dev@dpdk.org, bruce.richardson@intel.com, anatoly.burakov@intel.com Date: Mon, 26 Aug 2019 06:39:22 -0700 Message-ID: <156682676217.43940.3601940649943804836.stgit@jrharri1-skx> In-Reply-To: <156646334762.14099.13593080473257757748.stgit@jrharri1-skx> References: <156646334762.14099.13593080473257757748.stgit@jrharri1-skx> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [dpdk-dev] [PATCH v4] eal: use memzone to share tsc hz with secondary processes 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" Ideally, get_tsc_freq_arch() is able to provide the TSC rate using arch-specific means. When that is not possible, DPDK reverts to calculating the TSC rate with a 100ms nanosleep or 1s sleep. The latter occurs more frequently in VMs which often do not have access to the data they need from arch-specific means (CPUID leaf 0x15 or MSR 0xCE on x86). In secondary processes, the extra 100ms is especially noticeable and consumes the bulk of rte_eal_init() execution time. To resolve this extra delay, have the primary process put the TSC rate into a shared memory region that the secondary process can lookup. Reduces rte_eal_init() execution time in a secondary process from 165ms to 66ms on my test system. Signed-off-by: Jim Harris --- lib/librte_eal/common/eal_common_timer.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/common/eal_common_timer.c index 145543de7..b2c813444 100644 --- a/lib/librte_eal/common/eal_common_timer.c +++ b/lib/librte_eal/common/eal_common_timer.c @@ -15,9 +15,12 @@ #include #include #include +#include #include "eal_private.h" +static const char *MZ_RTE_TSC_FREQ = "rte_tsc_freq"; + /* The frequency of the RDTSC timer resolution */ static uint64_t eal_tsc_resolution_hz; @@ -77,9 +80,17 @@ estimate_tsc_freq(void) void set_tsc_freq(void) { - uint64_t freq; - - freq = get_tsc_freq_arch(); + const struct rte_memzone *mz; + uint64_t freq = 0; + + if (rte_eal_process_type() == RTE_PROC_SECONDARY) { + mz = rte_memzone_lookup(MZ_RTE_TSC_FREQ); + if (mz != NULL) { + freq = *(uint64_t *)mz->addr; + } + } + if (!freq) + freq = get_tsc_freq_arch(); if (!freq) freq = get_tsc_freq(); if (!freq) @@ -87,6 +98,13 @@ set_tsc_freq(void) RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000); eal_tsc_resolution_hz = freq; + if (rte_eal_process_type() == RTE_PROC_PRIMARY) { + mz = rte_memzone_reserve(MZ_RTE_TSC_FREQ, sizeof(uint64_t), + SOCKET_ID_ANY, 0); + if (mz != NULL) { + *(uint64_t *)mz->addr = freq; + } + } } void rte_delay_us_callback_register(void (*userfunc)(unsigned int))