From patchwork Fri Mar 12 07:29:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Leonardo_Br=C3=A1s?= X-Patchwork-Id: 1451741 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=WnrHTrQ9; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DxcwM6003z9sWC for ; Fri, 12 Mar 2021 18:32:35 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DxcwM4ywcz3dLl for ; Fri, 12 Mar 2021 18:32:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=WnrHTrQ9; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::732; helo=mail-qk1-x732.google.com; envelope-from=leobras.c@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=WnrHTrQ9; dkim-atps=neutral Received: from mail-qk1-x732.google.com (mail-qk1-x732.google.com [IPv6:2607:f8b0:4864:20::732]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DxcvY6N3hz3cjq for ; Fri, 12 Mar 2021 18:31:53 +1100 (AEDT) Received: by mail-qk1-x732.google.com with SMTP id x10so23383249qkm.8 for ; Thu, 11 Mar 2021 23:31:53 -0800 (PST) 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=fc4O5pv8w+UBOc7tpUHlG/tnzkEXWGcP/NkkMTj4HMY=; b=WnrHTrQ9rMGxhYK4b0QrGskBKMQhbpuaGqvmnn4rgSgmcAL3savA+xCqvbdGpvcgnE QDZWdRutIOgzjvPUmDleii6sqx+ju3o9ARd8iDbi/nH0zSrCM0TPYBiIfPp62qct0FRx s6r15iEep1O0HBzOd3W3cjg8zI6TSrLMj68rufPiOosq2deyRLPkw9RdXIJaUzI0tu8w sui28kyfCiSCYb66GXwEEPcaAezV7TXvqdYpuVq7usm7e/wnTOjO83e4Iq7sB6Oic79f xI5LWhh/V5SKNELDQ+jZYu7XrT9UWE4iEocRsY4UU6dh6U3pS55WxP/ZbCfuRR0y1w7u A4ow== 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=fc4O5pv8w+UBOc7tpUHlG/tnzkEXWGcP/NkkMTj4HMY=; b=FsBI72MHRA5bMBG4CvWxweAFTRbxSg0e4ttV5uy6bJl8CWVqOjjJBFtILYIw+zajgT 3/UGoDVx5At1qr8rKdiT84uBAS/TAXmIvXrFHMtr1zpBEmcC2BEEFMV3qui1309rHIMf B2kTUoujZoodQLPqt4GWzgAuT5qltzZ459r3Pyx2A1bI1PKxIeLfiKnmgqNnicmit5xp lTmmYJfMBsamvkstO7sGHwKIPZyuRL6/3cXsnZ9ErkrtEy6sTZtf7GyjqdZAkg9kF3yR 4ej37RbUpUn9/EdixMFGnlxVQBo4xyPHOKsmOHzJtdRiJzSryuPbSLziJZpVaQq4yS+/ a0oQ== X-Gm-Message-State: AOAM530cRxvrtnL3KP4BsrZjN4eSZRWt2DS4D/g72mnp9m3ghe3XZc5Y qz0bFxpQ4EvZUZUGQ+VOge8= X-Google-Smtp-Source: ABdhPJxPASBlXNxbx3G4ZP89CIihfT21I2UHj792PRIeqO9rwGBCFMzd1o926upif/uvr4znSkrsOA== X-Received: by 2002:a05:620a:31c:: with SMTP id s28mr11303310qkm.342.1615534308550; Thu, 11 Mar 2021 23:31:48 -0800 (PST) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com.com (177-131-89-8.dynamic.desktop.com.br. [177.131.89.8]) by smtp.gmail.com with ESMTPSA id t6sm3434026qti.2.2021.03.11.23.31.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 23:31:48 -0800 (PST) From: Leonardo Bras To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Andrew Morton , Leonardo Bras , Sandipan Das , "Aneesh Kumar K.V" , Logan Gunthorpe , Mike Rapoport , Bharata B Rao , Dan Williams , Nicholas Piggin , Nathan Lynch , David Hildenbrand , Laurent Dufour , Scott Cheloha , David Gibson Subject: [PATCH 1/3] powerpc/mm/hash: Avoid resizing-down HPT on first memory hotplug Date: Fri, 12 Mar 2021 04:29:39 -0300 Message-Id: <20210312072940.598696-2-leobras.c@gmail.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210312072940.598696-1-leobras.c@gmail.com> References: <20210312072940.598696-1-leobras.c@gmail.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Because hypervisors may need to create HPTs without knowing the guest page size, the smallest used page-size (4k) may be chosen, resulting in a HPT that is possibly bigger than needed. On a guest with bigger page-sizes, the amount of entries for HTP may be too high, causing the guest to ask for a HPT resize-down on the first hotplug. This becomes a problem when HPT resize-down fails, and causes the HPT resize to be performed on every LMB added, until HPT size is compatible to guest memory size, causing a major slowdown. So, avoiding HPT resizing-down on hot-add significantly improves memory hotplug times. As an example, hotplugging 256GB on a 129GB guest took 710s without this patch, and 21s after applied. Signed-off-by: Leonardo Bras --- arch/powerpc/mm/book3s64/hash_utils.c | 36 ++++++++++++++++----------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 73b06adb6eeb..cfb3ec164f56 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -794,7 +794,7 @@ static unsigned long __init htab_get_table_size(void) } #ifdef CONFIG_MEMORY_HOTPLUG -static int resize_hpt_for_hotplug(unsigned long new_mem_size) +static int resize_hpt_for_hotplug(unsigned long new_mem_size, bool shrinking) { unsigned target_hpt_shift; @@ -803,19 +803,25 @@ static int resize_hpt_for_hotplug(unsigned long new_mem_size) target_hpt_shift = htab_shift_for_mem_size(new_mem_size); - /* - * To avoid lots of HPT resizes if memory size is fluctuating - * across a boundary, we deliberately have some hysterisis - * here: we immediately increase the HPT size if the target - * shift exceeds the current shift, but we won't attempt to - * reduce unless the target shift is at least 2 below the - * current shift - */ - if (target_hpt_shift > ppc64_pft_size || - target_hpt_shift < ppc64_pft_size - 1) - return mmu_hash_ops.resize_hpt(target_hpt_shift); + if (shrinking) { - return 0; + /* + * To avoid lots of HPT resizes if memory size is fluctuating + * across a boundary, we deliberately have some hysterisis + * here: we immediately increase the HPT size if the target + * shift exceeds the current shift, but we won't attempt to + * reduce unless the target shift is at least 2 below the + * current shift + */ + + if (target_hpt_shift >= ppc64_pft_size - 1) + return 0; + + } else if (target_hpt_shift <= ppc64_pft_size) { + return 0; + } + + return mmu_hash_ops.resize_hpt(target_hpt_shift); } int hash__create_section_mapping(unsigned long start, unsigned long end, @@ -828,7 +834,7 @@ int hash__create_section_mapping(unsigned long start, unsigned long end, return -1; } - resize_hpt_for_hotplug(memblock_phys_mem_size()); + resize_hpt_for_hotplug(memblock_phys_mem_size(), false); rc = htab_bolt_mapping(start, end, __pa(start), pgprot_val(prot), mmu_linear_psize, @@ -847,7 +853,7 @@ int hash__remove_section_mapping(unsigned long start, unsigned long end) int rc = htab_remove_mapping(start, end, mmu_linear_psize, mmu_kernel_ssize); - if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC) + if (resize_hpt_for_hotplug(memblock_phys_mem_size(), true) == -ENOSPC) pr_warn("Hash collision while resizing HPT\n"); return rc; From patchwork Fri Mar 12 07:29:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Leonardo_Br=C3=A1s?= X-Patchwork-Id: 1451742 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=NG77WAYg; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Dxcwz0pJQz9sPf for ; Fri, 12 Mar 2021 18:33:07 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Dxcwy6thbz3dF8 for ; Fri, 12 Mar 2021 18:33:06 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=NG77WAYg; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::72b; helo=mail-qk1-x72b.google.com; envelope-from=leobras.c@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=NG77WAYg; dkim-atps=neutral Received: from mail-qk1-x72b.google.com (mail-qk1-x72b.google.com [IPv6:2607:f8b0:4864:20::72b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Dxcvc1Lpgz3d3C for ; Fri, 12 Mar 2021 18:31:56 +1100 (AEDT) Received: by mail-qk1-x72b.google.com with SMTP id 130so23352492qkh.11 for ; Thu, 11 Mar 2021 23:31:55 -0800 (PST) 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=z052sO/4NGB1LzTDqZ+gt7AUquJ7y9J7Drl1gXLThHU=; b=NG77WAYgsJT+VsleEY/Rphw3eS5xA0aCgIwZs1LZXaL5bN0l9hl1v8uAnYZuiKiaUK U4XnUtnxPm1lWURbJgD+Ksy+EJDQpuKVzGvMjBO2aLU5/bxG6Lh7cp06N85MIH1o3Apg aSGmvLfztbMxSZ5OX43sfVN28p1wz/nJBVvsv9YSDgpEoY/R/tZ3pqdpuWGvJ5EAdX6R RgXluxL5ZBQ8m5Peq3zvP0b3UwF9fNAKM4EDEjosSlLIdaBeOJtL9VHeZ9GfhyNNZtuE YDNV/SKTr2/MvU2p8XdEumcjABrSzYlAMC9VDBa5tDIxAya57cogGAHQV/bpZtnaqdfK Ugqg== 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=z052sO/4NGB1LzTDqZ+gt7AUquJ7y9J7Drl1gXLThHU=; b=E8IBRW+q9CXnvwzHxlzkTE7kxhgrH5Fe5MX9Gp9mxLLMajfKjL1AY8Z86TU2M1Kbh3 tc41wOuEXTIZv0tCRlX78XWwY3CuR2D+9kkUJQuyrDOOkzaYfU7jxPbVXjq/tN+tT4+6 z5fEG26mNzagjF8BddytFQlrj+2hAMQJxE6n7jqZyaJE9FRWRGxXaD6Wvb7AkRdR2RAP fYaqaPGLa/0/JreBh/s1qq01J7/D/XKyAePul2yNXFPYzogzNIu0izirC2eTqcps7P1J 8DDMVgNcope1ZPGdmRtGSzpzwZea8YkZ3eJpLtLxcaS2lQsA60qx8Ut2NEkFwOn/iswL RfwQ== X-Gm-Message-State: AOAM530CKwKbMmu+1R2m/uS7XBRG5TPyqSBnhSyXWuAF+hNlAMXzUlx0 LMjnJ7IXoUL+IN7z6u+yP7c= X-Google-Smtp-Source: ABdhPJyfSXCBtJL+8rrzAmK7RWJPFCVC4RYg2LBf6U8/N6ZSe055Myz7T7HEnkfqwjwo7XNHWtkL/g== X-Received: by 2002:a37:2756:: with SMTP id n83mr11259204qkn.70.1615534313731; Thu, 11 Mar 2021 23:31:53 -0800 (PST) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com.com (177-131-89-8.dynamic.desktop.com.br. [177.131.89.8]) by smtp.gmail.com with ESMTPSA id t6sm3434026qti.2.2021.03.11.23.31.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 23:31:53 -0800 (PST) From: Leonardo Bras To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Andrew Morton , Leonardo Bras , Sandipan Das , "Aneesh Kumar K.V" , Logan Gunthorpe , Mike Rapoport , Bharata B Rao , Dan Williams , Nicholas Piggin , Nathan Lynch , David Hildenbrand , Laurent Dufour , Scott Cheloha , David Gibson Subject: [PATCH 2/3] powerpc/mm/hash: Avoid multiple HPT resize-ups on memory hotplug Date: Fri, 12 Mar 2021 04:29:40 -0300 Message-Id: <20210312072940.598696-3-leobras.c@gmail.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210312072940.598696-1-leobras.c@gmail.com> References: <20210312072940.598696-1-leobras.c@gmail.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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/include/asm/sparsemem.h | 2 ++ arch/powerpc/mm/book3s64/hash_utils.c | 14 ++++++++++++++ arch/powerpc/mm/book3s64/pgtable.c | 6 ++++++ arch/powerpc/platforms/pseries/hotplug-memory.c | 6 ++++++ 5 files changed, 30 insertions(+) diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index d959b0195ad9..843b0a178590 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_memory_batch_expand_prepare(unsigned long newsize); + #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_BOOK3S_64_HASH_H */ diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h index d072866842e4..16b5f5300c84 100644 --- a/arch/powerpc/include/asm/sparsemem.h +++ b/arch/powerpc/include/asm/sparsemem.h @@ -17,6 +17,8 @@ extern int remove_section_mapping(unsigned long start, unsigned long end); extern int memory_add_physaddr_to_nid(u64 start); #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid +void memory_batch_expand_prepare(unsigned long newsize); + #ifdef CONFIG_NUMA extern int hot_add_scn_to_nid(unsigned long scn_addr); #else diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index cfb3ec164f56..1f6aa0bf27e7 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -858,6 +858,20 @@ int hash__remove_section_mapping(unsigned long start, unsigned long end) return rc; } + +void hash_memory_batch_expand_prepare(unsigned long newsize) +{ + /* + * 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"); + } +} #endif /* CONFIG_MEMORY_HOTPLUG */ static void __init hash_init_partition_table(phys_addr_t hash_table, diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index 5b3a3bae21aa..f1cd8af0f67f 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -193,6 +193,12 @@ int __meminit remove_section_mapping(unsigned long start, unsigned long end) return hash__remove_section_mapping(start, end); } + +void memory_batch_expand_prepare(unsigned long newsize) +{ + if (!radix_enabled()) + hash_memory_batch_expand_prepare(newsize); +} #endif /* CONFIG_MEMORY_HOTPLUG */ void __init mmu_partition_table_init(void) diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 8377f1f7c78e..353c71249214 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -671,6 +671,8 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add) if (lmbs_available < lmbs_to_add) return -EINVAL; + memory_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; @@ -734,6 +736,8 @@ static int dlpar_memory_add_by_index(u32 drc_index) pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index); + memory_batch_expand_prepare(memblock_phys_mem_size() + + drmem_info->n_lmbs * drmem_lmb_size()); lmb_found = 0; for_each_drmem_lmb(lmb) { if (lmb->drc_index == drc_index) { @@ -788,6 +792,8 @@ static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index) if (lmbs_available < lmbs_to_add) return -EINVAL; + memory_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; From patchwork Fri Mar 12 07:29:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Leonardo_Br=C3=A1s?= X-Patchwork-Id: 1451743 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=iT8PQhvR; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4DxcxR5DzNz9sPf for ; Fri, 12 Mar 2021 18:33:31 +1100 (AEDT) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4DxcxR4VLsz3d9G for ; Fri, 12 Mar 2021 18:33:31 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=iT8PQhvR; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::f2b; helo=mail-qv1-xf2b.google.com; envelope-from=leobras.c@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=iT8PQhvR; dkim-atps=neutral Received: from mail-qv1-xf2b.google.com (mail-qv1-xf2b.google.com [IPv6:2607:f8b0:4864:20::f2b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Dxcvj4lWwz3ckh for ; Fri, 12 Mar 2021 18:32:01 +1100 (AEDT) Received: by mail-qv1-xf2b.google.com with SMTP id a14so3832269qvj.7 for ; Thu, 11 Mar 2021 23:32:01 -0800 (PST) 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=ZEtUz4cca1c3Fl5qiQDKoYLrz6ESJJtyWLesvPnKSDE=; b=iT8PQhvRWLgLdesAqQvoHlBII0zpfG7wK5D8JyGWBsR97w6xqBm/UAzMn5xG1iMjI/ 5Vu4/MYUXNSWwAkdMg/Q/z7QQab5OA9O9muH+h0chtyy50D7of89f6HQWIw8gWuRDeT6 QTn4AAmHC4QRptq0vBm3Bu75CKASbkVd2AOq/Of0r9pSh1K8B2Gldie69c7Ytg3ZY7Ga xeAbWwdv5fomFwldof6Wkkws9QFF55xIc3kRAZtuImbRSY926SqbCQUm5joE4sAO4M6G 6HIBiYDMToAf8cfn1bd+frD5JPPlGz53RMlS1wz6izNkergvG0xOtdCckZYMOyQvXlRY wJlA== 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=ZEtUz4cca1c3Fl5qiQDKoYLrz6ESJJtyWLesvPnKSDE=; b=PLEhz7xcH6mahVadQ7E1avByZLDc2AxSrdKiA1SPGwgcrU32sCmhhijMHb39mpIHaM 1e4KFBRPk5L7ZvHdqc3mtpETvXt+iS4wgPxXZs/g0XfZRCXm1PyA88KMQK8ls2vPxXm1 6LJbKRt/s1RrUKvIMmqLS27a/vVByGgVIc7e6YfrjMPCE2eTzdo9bravX8p3JNmGeqR1 weu+Jh8MMRO3s+s9woY/a5qbZyjDP3N2B8QE6kzd1g6YJTlRKF+DFgmcKm/3XKVofihX TvXIK61AZAhdePjdABl8cVinkF77zmpAg8ps00xVsQyf2Oy+1eC12SFhEkc3t7rJ8iMm 3gQA== X-Gm-Message-State: AOAM533Gd2/gmQVWxNMhT2ux5s9A3hPIGOVThO7wdSf9uMZlrY88WTn9 3mYeGFOoHo+dZELvbdwQTsk= X-Google-Smtp-Source: ABdhPJwOJIMYFb2EtlgeCslrjHbdt3ioBTdrKL23cPfV68Ct+F6Lsz0Fql+YfcBk8Z7oPBByHoO9aQ== X-Received: by 2002:a0c:9cc2:: with SMTP id j2mr7724455qvf.2.1615534318818; Thu, 11 Mar 2021 23:31:58 -0800 (PST) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com.com (177-131-89-8.dynamic.desktop.com.br. [177.131.89.8]) by smtp.gmail.com with ESMTPSA id t6sm3434026qti.2.2021.03.11.23.31.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 23:31:58 -0800 (PST) From: Leonardo Bras To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Andrew Morton , Leonardo Bras , Sandipan Das , "Aneesh Kumar K.V" , Logan Gunthorpe , Mike Rapoport , Bharata B Rao , Dan Williams , Nicholas Piggin , Nathan Lynch , David Hildenbrand , Laurent Dufour , Scott Cheloha , David Gibson Subject: [PATCH 3/3] powerpc/mm/hash: Avoid multiple HPT resize-downs on memory hotunplug Date: Fri, 12 Mar 2021 04:29:41 -0300 Message-Id: <20210312072940.598696-4-leobras.c@gmail.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210312072940.598696-1-leobras.c@gmail.com> References: <20210312072940.598696-1-leobras.c@gmail.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" During memory hotunplug, after each LMB is removed, the HPT may be resized-down if it would map a max of 4 times the current amount of memory. (2 shifts, due to introduced histeresis) It usually is not an issue, but it can take a lot of time if HPT resizing-down fails. This happens because resize-down failures usually repeat at each LMB removal, until there are no more bolted entries conflict, which can take a while to happen. This can be solved by doing a single HPT resize at the end of memory hotunplug, after all requested entries are removed. To make this happen, it's necessary to temporarily disable all HPT resize-downs before hotunplug, re-enable them after hotunplug ends, and then resize-down HPT to the current memory size. As an example, hotunplugging 256GB from a 385GB guest took 621s without this patch, and 100s after applied. Signed-off-by: Leonardo Bras --- arch/powerpc/include/asm/book3s/64/hash.h | 2 ++ arch/powerpc/include/asm/sparsemem.h | 2 ++ arch/powerpc/mm/book3s64/hash_utils.c | 28 +++++++++++++++++++ arch/powerpc/mm/book3s64/pgtable.c | 12 ++++++++ .../platforms/pseries/hotplug-memory.c | 16 +++++++++++ 5 files changed, 60 insertions(+) diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index 843b0a178590..f92697c107f7 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -256,6 +256,8 @@ int hash__create_section_mapping(unsigned long start, unsigned long end, int hash__remove_section_mapping(unsigned long start, unsigned long end); void hash_memory_batch_expand_prepare(unsigned long newsize); +void hash_memory_batch_shrink_begin(void); +void hash_memory_batch_shrink_end(void); #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h index 16b5f5300c84..a7a8a0d070fc 100644 --- a/arch/powerpc/include/asm/sparsemem.h +++ b/arch/powerpc/include/asm/sparsemem.h @@ -18,6 +18,8 @@ extern int memory_add_physaddr_to_nid(u64 start); #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid void memory_batch_expand_prepare(unsigned long newsize); +void memory_batch_shrink_begin(void); +void memory_batch_shrink_end(void); #ifdef CONFIG_NUMA extern int hot_add_scn_to_nid(unsigned long scn_addr); diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 1f6aa0bf27e7..e16f207de8e4 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -794,6 +794,9 @@ static unsigned long __init htab_get_table_size(void) } #ifdef CONFIG_MEMORY_HOTPLUG + +atomic_t hpt_resize_disable = ATOMIC_INIT(0); + static int resize_hpt_for_hotplug(unsigned long new_mem_size, bool shrinking) { unsigned target_hpt_shift; @@ -805,6 +808,10 @@ static int resize_hpt_for_hotplug(unsigned long new_mem_size, bool shrinking) if (shrinking) { + /* When batch removing entries, only resizes HPT at the end. */ + if (atomic_read_acquire(&hpt_resize_disable)) + return 0; + /* * To avoid lots of HPT resizes if memory size is fluctuating * across a boundary, we deliberately have some hysterisis @@ -872,6 +879,27 @@ void hash_memory_batch_expand_prepare(unsigned long newsize) pr_warn("Hash collision while resizing HPT\n"); } } + +void hash_memory_batch_shrink_begin(void) +{ + /* Disable HPT resize-down during hot-unplug */ + atomic_set_release(&hpt_resize_disable, 1); +} + +void hash_memory_batch_shrink_end(void) +{ + unsigned long newsize; + + /* Re-enables HPT resize-down after hot-unplug */ + atomic_set_release(&hpt_resize_disable, 0); + + newsize = memblock_phys_mem_size(); + /* Resize to smallest SHIFT possible */ + while (resize_hpt_for_hotplug(newsize, true) == -ENOSPC) { + newsize *= 2; + pr_warn("Hash collision while resizing HPT\n"); + } +} #endif /* CONFIG_MEMORY_HOTPLUG */ static void __init hash_init_partition_table(phys_addr_t hash_table, diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index f1cd8af0f67f..e01681e22e00 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -199,6 +199,18 @@ void memory_batch_expand_prepare(unsigned long newsize) if (!radix_enabled()) hash_memory_batch_expand_prepare(newsize); } + +void memory_batch_shrink_begin(void) +{ + if (!radix_enabled()) + hash_memory_batch_shrink_begin(); +} + +void memory_batch_shrink_end(void) +{ + if (!radix_enabled()) + hash_memory_batch_shrink_end(); +} #endif /* CONFIG_MEMORY_HOTPLUG */ void __init mmu_partition_table_init(void) diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index 353c71249214..9182fb5b5c01 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c @@ -425,6 +425,8 @@ static int dlpar_memory_remove_by_count(u32 lmbs_to_remove) return -EINVAL; } + memory_batch_shrink_begin(); + for_each_drmem_lmb(lmb) { rc = dlpar_remove_lmb(lmb); if (rc) @@ -470,6 +472,8 @@ static int dlpar_memory_remove_by_count(u32 lmbs_to_remove) rc = 0; } + memory_batch_shrink_end(); + return rc; } @@ -481,6 +485,8 @@ static int dlpar_memory_remove_by_index(u32 drc_index) pr_debug("Attempting to hot-remove LMB, drc index %x\n", drc_index); + memory_batch_shrink_begin(); + lmb_found = 0; for_each_drmem_lmb(lmb) { if (lmb->drc_index == drc_index) { @@ -502,6 +508,8 @@ static int dlpar_memory_remove_by_index(u32 drc_index) else pr_debug("Memory at %llx was hot-removed\n", lmb->base_addr); + memory_batch_shrink_end(); + return rc; } @@ -532,6 +540,8 @@ static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index) if (lmbs_available < lmbs_to_remove) return -EINVAL; + memory_batch_shrink_begin(); + for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) { if (!(lmb->flags & DRCONF_MEM_ASSIGNED)) continue; @@ -572,6 +582,8 @@ static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index) } } + memory_batch_shrink_end(); + return rc; } @@ -700,6 +712,7 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add) if (lmbs_added != lmbs_to_add) { pr_err("Memory hot-add failed, removing any added LMBs\n"); + memory_batch_shrink_begin(); for_each_drmem_lmb(lmb) { if (!drmem_lmb_reserved(lmb)) continue; @@ -713,6 +726,7 @@ static int dlpar_memory_add_by_count(u32 lmbs_to_add) drmem_remove_lmb_reservation(lmb); } + memory_batch_shrink_end(); rc = -EINVAL; } else { for_each_drmem_lmb(lmb) { @@ -814,6 +828,7 @@ static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index) if (rc) { pr_err("Memory indexed-count-add failed, removing any added LMBs\n"); + memory_batch_shrink_begin(); for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) { if (!drmem_lmb_reserved(lmb)) continue; @@ -827,6 +842,7 @@ static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index) drmem_remove_lmb_reservation(lmb); } + memory_batch_shrink_end(); rc = -EINVAL; } else { for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {