From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933955AbeCHRFs (ORCPT ); Thu, 8 Mar 2018 12:05:48 -0500 Received: from mga17.intel.com ([192.55.52.151]:22992 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933407AbeCHRFq (ORCPT ); Thu, 8 Mar 2018 12:05:46 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,441,1515484800"; d="scan'208";a="32346792" From: "Luck, Tony" To: Borislav Petkov , "Prakhya, Sai Praneeth" CC: "linux-efi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Chun-Yi Lee , Will Deacon , "Hansen, Dave" , Mark Rutland , Bhupesh Sharma , "Neri, Ricardo" , "Shankar, Ravi V" , Matt Fleming , "Zijlstra, Peter" , Ard Biesheuvel , "Williams, Dan J" Subject: RE: [PATCH V2 2/3] efi: Introduce efi_rts_workqueue and some infrastructure to invoke all efi_runtime_services() Thread-Topic: [PATCH V2 2/3] efi: Introduce efi_rts_workqueue and some infrastructure to invoke all efi_runtime_services() Thread-Index: AQHTtNngZNpn0MRvAUySKQBVd1NV5aPFNzYAgAEifoCAAJCUgP//qb7g Date: Thu, 8 Mar 2018 17:05:44 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F7B392450@ORSMSX110.amr.corp.intel.com> References: <1520292190-5027-1-git-send-email-sai.praneeth.prakhya@intel.com> <1520292190-5027-3-git-send-email-sai.praneeth.prakhya@intel.com> <20180307121047.GG23662@pd.tnic> <20180308140830.GE21166@pd.tnic> In-Reply-To: <20180308140830.GE21166@pd.tnic> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNTc5MGYzZTQtZTRkNS00NjI1LThkYjYtMTYxZTdlYjRkZDY3IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjIuNS4xOCIsIlRydXN0ZWRMYWJlbEhhc2giOiJtXC9Yc1BsSHNIbXZNNE42SEYxQkpsdmc3RmpIR0VadXFqT1oyMjdCQWVjZ1RtUTdETUZaNWloUnBxQ2RIVHc4TSJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.22.254.138] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w28H5r6u021376 > "Hence, pstore calls efi_runtime_services() without using efi_rts_wq" - > that doesn't sound like optimal design to me. I would try to shove them > all through the workqueue - not have exceptions. But pstore is trying to save the last gasp dying words from a kernel that has paniced. There isn't any guarantee that work queue will run. I think it is reasonable to have some special case to make sure that we do save the information. But perhaps that special case should be to have pstore call directly into the guts of the EFI code and not worry about all these fancy switches of "mm" etc. This is true for the machine check logging case too, but the mitigation is that the details of the error persist in the machine check banks across the reset ... so all is not lost if the work queue isn't run here. -Tony