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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 781EFC433E2 for ; Thu, 10 Sep 2020 06:05:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35BA82076D for ; Thu, 10 Sep 2020 06:05:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="Lcg6e/Dj"; dkim=pass (1024-bit key) header.d=amazonses.com header.i=@amazonses.com header.b="gOQerc4S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729251AbgIJGFv (ORCPT ); Thu, 10 Sep 2020 02:05:51 -0400 Received: from a27-188.smtp-out.us-west-2.amazonses.com ([54.240.27.188]:53016 "EHLO a27-188.smtp-out.us-west-2.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728617AbgIJGFP (ORCPT ); Thu, 10 Sep 2020 02:05:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=zsmsymrwgfyinv5wlfyidntwsjeeldzt; d=codeaurora.org; t=1599717911; h=From:To:Cc:Subject:Date:Message-Id; bh=8aYBJyZG/tinKAweATWIriZSqX7vdJP9zCTtlHAcLSA=; b=Lcg6e/Dj72yrU0r4QxAVr5n0ECCw/tP2stjFzVqaWheuJjubdmn8zOq56lMcATVa t5sl8L0YPGcFqediX2Ahurdf5iTNpFf3YJVU1jax0Yur18iS16sa0dBZ2dL0dR7EtgX mmsoCpxC2Z6CVdj8f1X5IGYbHPT5SGFhXZvtDGBk= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=hsbnp7p3ensaochzwyq5wwmceodymuwv; d=amazonses.com; t=1599717911; h=From:To:Cc:Subject:Date:Message-Id:Feedback-ID; bh=8aYBJyZG/tinKAweATWIriZSqX7vdJP9zCTtlHAcLSA=; b=gOQerc4Sn+Q+y9FlB2vO/vYmsskvaQ+BYK4uvP9y7QG5V+PTjaWDZi2uTxGaxWQo YzD8rKO+2IOQAFdw4o18YX6r1GLPpOk1rLmi0x0wLk2VPhbAktnZtDQWgus9p5RMbMi C5rxQWwcChMTVTp2qxf2jQkiu1fnRJfw5+WUaxfs= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 06DEAC433CA 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] arm64/mm: add fallback option to allocate virtually contiguous memory Date: Thu, 10 Sep 2020 06:05:11 +0000 Message-ID: <01010174769e2cc4-79f26633-9a7d-48d5-a13b-af8c8486975e-000000@us-west-2.amazonses.com> X-Mailer: git-send-email 2.7.4 X-SES-Outgoing: 2020.09.10-54.240.27.188 Feedback-ID: 1.us-west-2.CZuq2qbDmUIuT3qdvXlRHZZCpfZqZ4GtG9v3VKgRyF0=:AmazonSES Sender: linux-kernel-owner@vger.kernel.org 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_SZIE 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 | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 75df62f..a46c7d4 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1100,6 +1100,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, p4d_t *p4dp; pud_t *pudp; pmd_t *pmdp; + int ret = 0; do { next = pmd_addr_end(addr, end); @@ -1121,15 +1122,23 @@ 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) { +#ifdef CONFIG_MEMORY_HOTPLUG + vmemmap_free(start, end, altmap); +#endif + ret = -ENOMEM; + break; + } pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL)); } else vmemmap_verify((pte_t *)pmdp, node, addr, next); } while (addr = next, addr != end); - return 0; + if (ret) + return vmemmap_populate_basepages(start, end, node, altmap); + else + return ret; } #endif /* !ARM64_SWAPPER_USES_SECTION_MAPS */ void vmemmap_free(unsigned long start, unsigned long end, -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project