From patchwork Wed Mar 9 13:22:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Hunt, David" X-Patchwork-Id: 108620 X-Patchwork-Delegate: thomas@monjalon.net Return-Path: X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id ED490A0093; Wed, 9 Mar 2022 14:22:51 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7E2DC40687; Wed, 9 Mar 2022 14:22:51 +0100 (CET) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by mails.dpdk.org (Postfix) with ESMTP id A7A9F40395 for ; Wed, 9 Mar 2022 14:22:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646832169; x=1678368169; h=from:to:cc:subject:date:message-id; bh=RZCsRh8v/LOlVPv6murULQ+QBjGAAbirIp7OIQPi6sQ=; b=nlVDl68X1KxtHFRsuMLQIh25wrSvTbu1pJpDE1Y69vpfjkUn5t9/u9Lf SemPTyDFduNgnK96k6OYZ8fzXzPrPy9VrnCUxR7l8fUbrRH/HWjtIhYGV mUuLo83+9Kkf6lF/cswue4Noy+Yb3IAHJPfkePetx3sTZOdXU5P+r2dt1 j9NjI0jdCN89Rcg9HOaoRo/7P7lPz7OK5zcdEF0qanrTZ3SJL/cmZjzHq fjU044Wqdi0Lk4YNss0k6s4U9WaSpcowddsW0jqk7cBibH35nv/D1QoqY JPll5UF2vNEjD3ZTObtCDPDZsjIXAc9bYNWyWI7UwY7aUHWgMDQhKY5E1 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10280"; a="341401148" X-IronPort-AV: E=Sophos;i="5.90,167,1643702400"; d="scan'208";a="341401148" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Mar 2022 05:22:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,167,1643702400"; d="scan'208";a="554112579" Received: from silpixa00399952.ir.intel.com ([10.55.129.92]) by orsmga008.jf.intel.com with ESMTP; 09 Mar 2022 05:22:47 -0800 From: David Hunt To: dev@dpdk.org Cc: david.hunt@intel.com Subject: [PATCH] lib/power: power pmd errata with RTM and gcc-9 Date: Wed, 9 Mar 2022 13:22:21 +0000 Message-Id: <20220309132221.18210-1-david.hunt@intel.com> X-Mailer: git-send-email 2.17.1 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org An errata exists where users may see reduced power savings when using PMD Power Management. This issue occurs when compiling DPDK applications with gcc-9 on platforms with TSX enabled. In rte_power_monitor_multi(), the function may return without successfully starting the RTM transaction (the _xbegin() fails). Signed-off-by: David Hunt --- doc/guides/rel_notes/release_22_03.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst index 60e5b4f9aa..34d6f34dba 100644 --- a/doc/guides/rel_notes/release_22_03.rst +++ b/doc/guides/rel_notes/release_22_03.rst @@ -313,6 +313,17 @@ Known Issues Also, make sure to start the actual text at the margin. ======================================================= +* **Possible reduced power saving with PMD Power Management.** + + Users may see reduced power savings when using PMD Power Management. + This issue occurs when compiling DPDK applications with gcc-9 on + platforms with TSX enabled. In rte_power_monitor_multi(), the + function may return without successfully starting the RTM + transaction (the _xbegin() fails). + + There are three workarounds for this issue. Either build DPDK with gcc-11 + or newer, build with shared libraries, or build DPDK with fewer drivers. + Tested Platforms ----------------