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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 3CA3DC433B4 for ; Fri, 30 Apr 2021 14:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07182613CC for ; Fri, 30 Apr 2021 14:37:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232951AbhD3Ohx (ORCPT ); Fri, 30 Apr 2021 10:37:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230351AbhD3Oht (ORCPT ); Fri, 30 Apr 2021 10:37:49 -0400 Received: from mail-qt1-x82e.google.com (mail-qt1-x82e.google.com [IPv6:2607:f8b0:4864:20::82e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DAEDC06174A for ; Fri, 30 Apr 2021 07:37:01 -0700 (PDT) Received: by mail-qt1-x82e.google.com with SMTP id j19so11446164qtx.13 for ; Fri, 30 Apr 2021 07:37:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=nrdezJ4pdCtm9VV6EXYt28y/b60CBWuF37yCYjbQazM=; b=rO50kzg0l9E+8Eg+I65gJrSxNnjQtRijxEk2BsbLQoYrMAxxd+6IJf1LdDx3tU5zev 1nqp89tKL4Rh4bgn/90v/493AFaPuDvFQvFoAbjKgeE0zh4bGQE0p2h3ASQiTOJWKOpl FmebhSkeRXDQyEoXa30OO/Ij+zkoURFOYaNXF1683ve/nowQwTk0KD1CDHG2hezw4fQY zp5R6jBHMdgfiuC1k7pAZAL4hEqTAS5TVLcmmd0JiXVOJRgAw1DDkI4SenOD7kqRcNVi tnCPDB7CVNWHug6yLfQR2AMxXgDlqZhh1Bsfbk4bY44wIw1jcLAz8JEw330qSLsfOgqR HEtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=nrdezJ4pdCtm9VV6EXYt28y/b60CBWuF37yCYjbQazM=; b=MjNtcfTa+lK0SryEMetSKz8sluU5DvFiYYYsItFPNCiuUN8lLYPf2Xh1jEoQ3HKDtm CyBgb3OeK5bnQP9RL4kNJBM7q5Racw5wu+xfEP/JsBwn553ZAi+F3z7vQCqXcNLIn4sh 1RyC8xI3Lul81jpyplauFxSmjR4tkrXnojT1bpNu+xM6fDvLu1tF+Xk4RYGA8OpUb2TI v0GSrBAgI9c5LFOUr9zCv9io/Y485vARpV7dFM/il7tuwFbQv82uRmMK4dNTBBwPPfHv HYF+2SKor9iBN7ObAglJbJk2DeF4jZanMvX3vfkxUKTgDmzSz078MIdGMxWzfguZuO11 Xx1Q== X-Gm-Message-State: AOAM531T903K7qBwzLhVieuiExjRQLO25UBPm4Nqe0WPkZ+jQ5bic7wo 5XNvFmyy4hiijSgy/em8W/c= X-Google-Smtp-Source: ABdhPJxhmKbcPVKKKaeOcfVyZbISGyjoYrD0vwX7Ak3/6ff5O4h3kDte6NVXtK31M5o/UXRQAe2Dew== X-Received: by 2002:ac8:75ca:: with SMTP id z10mr4722997qtq.137.1619793420373; Fri, 30 Apr 2021 07:37:00 -0700 (PDT) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com.com ([2804:14c:482:7b04::1001]) by smtp.gmail.com with ESMTPSA id 190sm1532560qki.115.2021.04.30.07.36.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Apr 2021 07:37:00 -0700 (PDT) From: Leonardo Bras To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Leonardo Bras , Sandipan Das , Mike Rapoport , Andrew Morton , "Aneesh Kumar K.V" , Nicholas Piggin , Nathan Lynch , David Hildenbrand , Scott Cheloha , Laurent Dufour Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/3] powerpc/mm/hash: Avoid multiple HPT resize-ups on memory hotplug Date: Fri, 30 Apr 2021 11:36:08 -0300 Message-Id: <20210430143607.135005-3-leobras.c@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210430143607.135005-1-leobras.c@gmail.com> References: <20210430143607.135005-1-leobras.c@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Every time a memory hotplug happens, and the memory limit crosses a 2^n value, it may be necessary to perform HPT resizing-up, which can take some time (over 100ms in my tests). It usually is not an issue, but it can take some time if a lot of memory is added to a guest with little starting memory: Adding 256G to a 2GB guest, for example will require 8 HPT resizes. Perform an HPT resize before memory hotplug, updating HPT to its final size (considering a successful hotplug), taking the number of HPT resizes to at most one per memory hotplug action. Signed-off-by: Leonardo Bras --- arch/powerpc/include/asm/book3s/64/hash.h | 2 ++ arch/powerpc/mm/book3s64/hash_utils.c | 20 +++++++++++++++++++ .../platforms/pseries/hotplug-memory.c | 9 +++++++++ 3 files changed, 31 insertions(+) diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index d959b0195ad9..fad4af8b8543 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -255,6 +255,8 @@ int hash__create_section_mapping(unsigned long start, unsigned long end, int nid, pgprot_t prot); int hash__remove_section_mapping(unsigned long start, unsigned long end); +void hash_batch_expand_prepare(unsigned long newsize); + #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_BOOK3S_64_HASH_H */ diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 608e4ed397a9..3fa395b3fe57 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -859,6 +859,26 @@ int hash__remove_section_mapping(unsigned long start, unsigned long end) return rc; } + +void hash_batch_expand_prepare(unsigned long newsize) +{ + const u64 starting_size = ppc64_pft_size; + + /* + * Resizing-up HPT should never fail, but there are some cases system starts with higher + * SHIFT than required, and we go through the funny case of resizing HPT down while + * adding memory + */ + + while (resize_hpt_for_hotplug(newsize, false) == -ENOSPC) { + newsize *= 2; + pr_warn("Hash collision while resizing HPT\n"); + + /* Do not try to resize to the starting size, or bigger value */ + if (htab_shift_for_mem_size(newsize) >= starting_size) + break; + } +} #endif /* CONFIG_MEMORY_HOTPLUG */ static void __init hash_init_partition_table(phys_addr_t hash_table, diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 8377f1f7c78e..48b2cfe4ce69 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -671,6 +672,10 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add) if (lmbs_available < lmbs_to_add) return -EINVAL; + if (!radix_enabled()) + hash_batch_expand_prepare(memblock_phys_mem_size() + + lmbs_to_add * drmem_lmb_size()); + for_each_drmem_lmb(lmb) { if (lmb->flags & DRCONF_MEM_ASSIGNED) continue; @@ -788,6 +793,10 @@ static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index) if (lmbs_available < lmbs_to_add) return -EINVAL; + if (!radix_enabled()) + hash_batch_expand_prepare(memblock_phys_mem_size() + + lmbs_to_add * drmem_lmb_size()); + for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) { if (lmb->flags & DRCONF_MEM_ASSIGNED) continue; -- 2.30.2