From patchwork Mon Jul 27 16:29:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 11687211 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AAD4E138C for ; Mon, 27 Jul 2020 16:30:49 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8973B20719 for ; Mon, 27 Jul 2020 16:30:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="KtM0Agb5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8973B20719 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 5F017123E392D; Mon, 27 Jul 2020 09:30:49 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=rppt@kernel.org; receiver= Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (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 4F97F123E3923 for ; Mon, 27 Jul 2020 09:30:47 -0700 (PDT) Received: from aquarius.haifa.ibm.com (nesher1.haifa.il.ibm.com [195.110.40.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 286AF2074F; Mon, 27 Jul 2020 16:30:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595867447; bh=/Qw/NeLTpR/6aCJ04huD3Mp72u1Bfe6uWLUqSL0Zn2g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KtM0Agb5HnPUkY+CbqIdR37o127nhQKSy5Dq+iFtbhAZ5rXOrCF/TCi/y9dVBPJgG ESLcg0dYR67EEDk5MwOpPeS2zHrUXad+3m3RPRP3kklfQeu9q9pdGF6IS3dzaGLPnI xswjDrT4XhuX8HarB2l6OUZFzMfxbAPY98Qdg+hQ= From: Mike Rapoport To: linux-kernel@vger.kernel.org Subject: [PATCH v2 7/7] mm: secretmem: add ability to reserve memory at boot Date: Mon, 27 Jul 2020 19:29:35 +0300 Message-Id: <20200727162935.31714-8-rppt@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200727162935.31714-1-rppt@kernel.org> References: <20200727162935.31714-1-rppt@kernel.org> MIME-Version: 1.0 Message-ID-Hash: YE7C5CXKONS6SP55HY4Y4KSD5TM4DQJQ X-Message-ID-Hash: YE7C5CXKONS6SP55HY4Y4KSD5TM4DQJQ X-MailFrom: rppt@kernel.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Alexander Viro , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Christopher Lameter , Dave Hansen , Elena Reshetova , "H. Peter Anvin" , Idan Yaniv , Ingo Molnar , James Bottomley , "Kirill A. Shutemov" , Matthew Wilcox , Mike Rapoport , Mike Rapoport , Michael Kerrisk , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Thomas Gleixner , Tycho Andersen , Will Deacon , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org, x86@kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: From: Mike Rapoport Taking pages out from the direct map and bringing them back may create undesired fragmentation and usage of the smaller pages in the direct mapping of the physical memory. This can be avoided if a significantly large area of the physical memory would be reserved for secretmem purposes at boot time. Add ability to reserve physical memory for secretmem at boot time using "secretmem" kernel parameter and then use that reserved memory as a global pool for secret memory needs. Signed-off-by: Mike Rapoport --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb95fad81c79..6f3c2f28160f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4548,6 +4548,10 @@ Format: integer between 0 and 10 Default is 0. + secretmem=n[KMG] + [KNL,BOOT] Reserve specified amount of memory to + back mappings of secret memory. + skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate xtime_lock contention on larger systems, and/or RCU lock contention on all systems with CONFIG_MAXSMP set.