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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96ED3C43334 for ; Sun, 19 Jun 2022 13:39:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237781AbiFSNjs (ORCPT ); Sun, 19 Jun 2022 09:39:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237340AbiFSNja (ORCPT ); Sun, 19 Jun 2022 09:39:30 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64A2EDEAF for ; Sun, 19 Jun 2022 06:39:08 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id k12-20020a17090a404c00b001eaabc1fe5dso8494791pjg.1 for ; Sun, 19 Jun 2022 06:39:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=EMatSV1+t4qFy1NZ5GBQuBSsvAWCaC/xn6RiPVNR2iY=; b=egHHCkuudg/7I8ZBB5X4/KpYkcCBo1KW8NC5gvcUAbUmJuJzsaOvA/wvkAMnpEImG6 Xwt3fJTLMv+n0o/HKvIYPjPKkreRvNNwwfabkvMQbi6FV4wT4dRS+UCBQzCUrwCAz2Nh hbnlbsf6Mp1GqYpyQi0tZs3KGvp2FWJ2SQ+FrUlVi2DqzQpHOnHr1Y01R0wEfpX4Pt1K SjBpW0zFJ3UjmpnM3BxZ7vYtdqF36EVZDzcx7qtyfiy2Wq1o0RjHydJ6Et75P5MwdTCH 7BfrqaL5aoqghMRVQJZIz+pAxvlVjTHg+3E3B32w7R8fQWR3NAkEWMuQuweJ5YwVvSVU 8K/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=EMatSV1+t4qFy1NZ5GBQuBSsvAWCaC/xn6RiPVNR2iY=; b=qVIHCKtUb21NkHVZ3d8v0NYa/Ti+3IwKXh33eM4R+xi+jFJMIHCnXpXbWGj9PXGqpj E2w2mVnngTMnPs5WcXopUlwbWQnvmWz0UYoOvQEwk/Jo+gThDRcV5ujXcbD/KzBRGDRW DswGU8HcX8wZ+5UCeuFeqSd/wSN0Blg10Kk5LslrSyfAbioDpM1rQJlSccLGlBHUbAl9 b9cGoG5kflLs1lYakyRZAFlbG1p1INSJcLdEUqaSyBHnYTaPExwGi0NZe+r5KoVAMWmx 7WjHoDOQKCPjwIIs7xvFeoeaQjJ/mqMome40kqNnFjEZW6NoFthvEWYj+fijHXoddkAS CD2g== X-Gm-Message-State: AJIora8UVh699gvtkMgtBnwrvOARbuRBDtcEaBI8xchjMG72z8KYfPY6 k3fYVHoSJYgXn9gBgF+nnrXoIA== X-Google-Smtp-Source: AGRyM1teSCoKuhJy4pJtr6LdpTRxLya/8YCG8snNHMD8qJItI0CGEttEwXXS3E/TvTZOXzPXNFC7cQ== X-Received: by 2002:a17:902:7e84:b0:166:395c:4b68 with SMTP id z4-20020a1709027e8400b00166395c4b68mr19417328pla.8.1655645947264; Sun, 19 Jun 2022 06:39:07 -0700 (PDT) Received: from FVFYT0MHHV2J.bytedance.net ([139.177.225.255]) by smtp.gmail.com with ESMTPSA id y23-20020a056a001c9700b0051b95c76752sm6990982pfw.153.2022.06.19.06.39.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 19 Jun 2022 06:39:07 -0700 (PDT) From: Muchun Song To: akpm@linux-foundation.org, corbet@lwn.net, david@redhat.com, mike.kravetz@oracle.com, osalvador@suse.de, paulmck@kernel.org Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, smuchun@gmail.com, Muchun Song Subject: [PATCH v4 1/2] mm: memory_hotplug: enumerate all supported section flags Date: Sun, 19 Jun 2022 21:38:50 +0800 Message-Id: <20220619133851.68184-2-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.1 (Apple Git-133) In-Reply-To: <20220619133851.68184-1-songmuchun@bytedance.com> References: <20220619133851.68184-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org We are almost running out of section flags, only one bit is available in the worst case (powerpc with 256k pages). However, there are still some free bits (in ->section_mem_map) on other architectures (e.g. x86_64 has 10 bits available, arm64 has 8 bits available with worst case of 64K pages). We have hard coded those numbers in code, it is inconvenient to use those bits on other architectures except powerpc. So transfer those section flags to enumeration to make it easy to add new section flags in the future. Also, move SECTION_TAINT_ZONE_DEVICE into the scope of CONFIG_ZONE_DEVICE to save a bit on non-zone-device case. Signed-off-by: Muchun Song --- include/linux/mmzone.h | 44 +++++++++++++++++++++++++++++++++++--------- mm/memory_hotplug.c | 6 ++++++ mm/sparse.c | 2 +- 3 files changed, 42 insertions(+), 10 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index aab70355d64f..932843c6459b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1418,16 +1418,35 @@ extern size_t mem_section_usage_size(void); * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the * worst combination is powerpc with 256k pages, * which results in PFN_SECTION_SHIFT equal 6. - * To sum it up, at least 6 bits are available. + * To sum it up, at least 6 bits are available on all architectures. + * However, we can exceed 6 bits on some other architectures except + * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available + * with the worst case of 64K pages on arm64) if we make sure the + * exceeded bit is not applicable to powerpc. */ -#define SECTION_MARKED_PRESENT (1UL<<0) -#define SECTION_HAS_MEM_MAP (1UL<<1) -#define SECTION_IS_ONLINE (1UL<<2) -#define SECTION_IS_EARLY (1UL<<3) -#define SECTION_TAINT_ZONE_DEVICE (1UL<<4) -#define SECTION_MAP_LAST_BIT (1UL<<5) -#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) -#define SECTION_NID_SHIFT 6 +enum { + SECTION_MARKED_PRESENT_BIT, + SECTION_HAS_MEM_MAP_BIT, + SECTION_IS_ONLINE_BIT, + SECTION_IS_EARLY_BIT, +#ifdef CONFIG_ZONE_DEVICE + SECTION_TAINT_ZONE_DEVICE_BIT, +#endif + SECTION_MAP_LAST_BIT, +}; + +enum { + SECTION_MARKED_PRESENT = BIT(SECTION_MARKED_PRESENT_BIT), + SECTION_HAS_MEM_MAP = BIT(SECTION_HAS_MEM_MAP_BIT), + SECTION_IS_ONLINE = BIT(SECTION_IS_ONLINE_BIT), + SECTION_IS_EARLY = BIT(SECTION_IS_EARLY_BIT), +#ifdef CONFIG_ZONE_DEVICE + SECTION_TAINT_ZONE_DEVICE = BIT(SECTION_TAINT_ZONE_DEVICE_BIT), +#endif +}; + +#define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1)) +#define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT static inline struct page *__section_mem_map_addr(struct mem_section *section) { @@ -1466,12 +1485,19 @@ static inline int online_section(struct mem_section *section) return (section && (section->section_mem_map & SECTION_IS_ONLINE)); } +#ifdef CONFIG_ZONE_DEVICE static inline int online_device_section(struct mem_section *section) { unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE; return section && ((section->section_mem_map & flags) == flags); } +#else +static inline int online_device_section(struct mem_section *section) +{ + return 0; +} +#endif static inline int online_section_nr(unsigned long nr) { diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1f1a730c4499..6662b86e9e64 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -670,12 +670,18 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon } +#ifdef CONFIG_ZONE_DEVICE static void section_taint_zone_device(unsigned long pfn) { struct mem_section *ms = __pfn_to_section(pfn); ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; } +#else +static inline void section_taint_zone_device(unsigned long pfn) +{ +} +#endif /* * Associate the pfn range with the given zone, initializing the memmaps diff --git a/mm/sparse.c b/mm/sparse.c index cb3bfae64036..e5a8a3a0edd7 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -281,7 +281,7 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p { unsigned long coded_mem_map = (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); - BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL< PFN_SECTION_SHIFT); BUG_ON(coded_mem_map & ~SECTION_MAP_MASK); return coded_mem_map; } -- 2.11.0