From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.31; helo=mga06.intel.com; envelope-from=jian.j.wang@intel.com; receiver=edk2-devel@lists.01.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 6EC4A2222C24D for ; Fri, 26 Jan 2018 00:57:57 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jan 2018 01:03:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,415,1511856000"; d="scan'208";a="25622243" Received: from jwang36-mobl2.ccr.corp.intel.com ([10.239.192.179]) by fmsmga001.fm.intel.com with ESMTP; 26 Jan 2018 01:03:26 -0800 From: Jian J Wang To: edk2-devel@lists.01.org Cc: Ruiyu Ni , Jiewen Yao , Eric Dong , Laszlo Ersek Date: Fri, 26 Jan 2018 17:03:06 +0800 Message-Id: <20180126090307.6872-2-jian.j.wang@intel.com> X-Mailer: git-send-email 2.15.1.windows.2 In-Reply-To: <20180126090307.6872-1-jian.j.wang@intel.com> References: <20180126090307.6872-1-jian.j.wang@intel.com> Subject: [PATCH 1/2] UefiCpuPkg/MpInitLib: force flushing TLB for AP in mwait loop mode X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Jan 2018 08:57:57 -0000 The reason doing this is that we found that calling StartupAllAps() to flush TLB for all APs in CpuDxe driver after changing page attributes will spend a lot of time to complete. If there are many page attributes update requests, the whole system performance will be slowed down explicitly, including any shell command and UI operation. The solution is removing the flush operation for AP in CpuDxe driver. Since TLB is always flushed in HLT loop mode, we just need to enforce a TLB flush for mwait loop mode. Cc: Ruiyu Ni Cc: Jiewen Yao Cc: Eric Dong Cc: Laszlo Ersek Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang --- UefiCpuPkg/Library/MpInitLib/MpLib.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index 6231968c74..175a4b49e5 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -630,6 +630,12 @@ ApWakeupFunction ( // Restore AP's volatile registers saved // RestoreVolatileRegisters (&CpuMpData->CpuData[ProcessorNumber].VolatileRegisters, TRUE); + } else { + // + // Due to performance concern, the CPU driver might not flush TLB for + // APs on spot. AP itself needs to take care of it when woken up. + // + CpuFlushTlb (); } if (GetApState (&CpuMpData->CpuData[ProcessorNumber]) == CpuStateReady) { -- 2.15.1.windows.2