From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2588C4363D for ; Wed, 30 Sep 2020 23:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DAA1206C1 for ; Wed, 30 Sep 2020 23:14:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="lCzO+LVA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732116AbgI3XO2 (ORCPT ); Wed, 30 Sep 2020 19:14:28 -0400 Received: from m42-4.mailgun.net ([69.72.42.4]:60048 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730528AbgI3XOL (ORCPT ); Wed, 30 Sep 2020 19:14:11 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1601507650; h=References: In-Reply-To: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=vkdiR7P09PCkbB+18oqh3xH2FAGNblOXdWhB2pw9H2E=; b=lCzO+LVAc3Arw7WlOv/uNWduAsiaRlGqVFIKXjMOKjbA5xoeqimyCE8QayyibHk1/mkNpeJt fwEXt6qaP15xXVZ6i7wmpumKlYLqYvmRb3e9g/q8wSs3ebDvMl1W99OGhaycuz+ZdGCxr+36 PCjUKKwEIoYLjAt4WTjExo3Sr8U= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-west-2.postgun.com with SMTP id 5f75112f25e92f5003058e99 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 30 Sep 2020 23:13:51 GMT Sender: sudaraja=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id AC648C433C8; Wed, 30 Sep 2020 23:13:51 +0000 (UTC) Received: from th-lint-014.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sudaraja) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4400EC433C8; Wed, 30 Sep 2020 23:13:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4400EC433C8 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=sudaraja@codeaurora.org From: Sudarshan Rajagopalan To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Sudarshan Rajagopalan , Catalin Marinas , Will Deacon , Anshuman Khandual , Mark Rutland , Logan Gunthorpe , David Hildenbrand , Andrew Morton , Steven Price Subject: [PATCH v2] arm64/mm: add fallback option to allocate virtually contiguous memory Date: Wed, 30 Sep 2020 16:13:25 -0700 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When section mappings are enabled, we allocate vmemmap pages from physically continuous memory of size PMD_SIZE using vmemmap_alloc_block_buf(). Section mappings are good to reduce TLB pressure. But when system is highly fragmented and memory blocks are being hot-added at runtime, its possible that such physically continuous memory allocations can fail. Rather than failing the memory hot-add procedure, add a fallback option to allocate vmemmap pages from discontinuous pages using vmemmap_populate_basepages(). Signed-off-by: Sudarshan Rajagopalan Cc: Catalin Marinas Cc: Will Deacon Cc: Anshuman Khandual Cc: Mark Rutland Cc: Logan Gunthorpe Cc: David Hildenbrand Cc: Andrew Morton Cc: Steven Price --- arch/arm64/mm/mmu.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 75df62f..9edbbb8 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1121,8 +1121,18 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, void *p = NULL; p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap); - if (!p) - return -ENOMEM; + if (!p) { + if (altmap) + return -ENOMEM; /* no fallback */ + + /* + * fallback allocating with virtually + * contiguous memory for this section + */ + if (vmemmap_populate_basepages(addr, next, node, NULL)) + return -ENOMEM; + continue; + } pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL)); } else -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project