From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsNvVr/WKUc32nGC1cu2Em9nGgs1JTmhB5qh5IklSXLJ7llJEBQzU6p7MzAfA+ELFfQ4oIF ARC-Seal: i=1; a=rsa-sha256; t=1519787019; cv=none; d=google.com; s=arc-20160816; b=qoeSnGy3Vi8xSwg6hvb6ah3GArPANt9bCz7rmTEqy4wkqwY+PIZBfOhN8lAqdmtTjE mjuoGNVqjyW1uuhSGqUEWK1XiQ8D2gGe7CQRJxY0odllTM1AxyPjoMwqgigpilF5I6EF pKaMpJkLcP9pPi2J3SIia3CCAPufBc+c66m+nh2ZRKkjQrXyUtA14JV3D9BB6oQz3W0e dKZm1G+NXxRl5/EDqm/c8/g5gWF8coygWwap5x2KIrFQWWd78Cl6U/pz9I0u21V6labv 94NhiAEaCxlt0aVNfUCRzR343iaZuWgz9uGOgbUIv0F9epPC5TDXJYuqk7Jk6JuXuxTr MGMA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:to:from :dkim-signature:arc-authentication-results; bh=WdpVhJl7PHM5XouF/F1etdV62yGyC4doJFh2uBAg9dE=; b=mv+U/kreVFcUZenv8FLabR+lY6F0csohEg0UcLgXckU1Vh3X+HUdLV5aULFmIrnLmk AFwrjc74NRluERG/zLU4/ThzTGnHFhhUisNbG7I5X+0EOSprhI0Fc3/1tcoAnGiF/Xvf cAIPAEjrPmY9xpSLUDXKTrG/t5jO55Y0uSF5xcj96ZdjOnOan/EgDIhv1UwM2OvlYm5l L+h+hWH5h556U+ePXYM/XykGEgXeOd8NRQf+dkBIrkERcLCmdRFYVoorXqfDVqXtGwl2 Y6jvezMeAiYNXquC6oGkH4CdikRSwocRpItMVoMHONpSU8caBp/0JCnpCTXGqWxW18Q/ eRNQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=dhUlnbYL; spf=pass (google.com: domain of pasha.tatashin@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=pasha.tatashin@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=dhUlnbYL; spf=pass (google.com: domain of pasha.tatashin@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=pasha.tatashin@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com From: Pavel Tatashin To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, akpm@linux-foundation.org, mgorman@techsingularity.net, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, vbabka@suse.cz, bharata@linux.vnet.ibm.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, dan.j.williams@intel.com, kirill.shutemov@linux.intel.com, bhe@redhat.com Subject: [v5 6/6] mm/memory_hotplug: optimize memory hotplug Date: Tue, 27 Feb 2018 22:03:08 -0500 Message-Id: <20180228030308.1116-7-pasha.tatashin@oracle.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180228030308.1116-1-pasha.tatashin@oracle.com> References: <20180228030308.1116-1-pasha.tatashin@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8817 signatures=668681 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=65 spamscore=0 mlxscore=0 mlxlogscore=699 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802280034 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593612193900570371?= X-GMAIL-MSGID: =?utf-8?q?1593612193900570371?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: During memory hotplugging we traverse struct pages three times: 1. memset(0) in sparse_add_one_section() 2. loop in __add_section() to set do: set_page_node(page, nid); and SetPageReserved(page); 3. loop in memmap_init_zone() to call __init_single_pfn() This patch removes the first two loops, and leaves only loop 3. All struct pages are initialized in one place, the same as it is done during boot. The benefits: - We improve memory hotplug performance because we are not evicting the cache several times and also reduce loop branching overhead. - Remove condition from hotpath in __init_single_pfn(), that was added in order to fix the problem that was reported by Bharata in the above email thread, thus also improve performance during normal boot. - Make memory hotplug more similar to the boot memory initialization path because we zero and initialize struct pages only in one function. - Simplifies memory hotplug struct page initialization code, and thus enables future improvements, such as multi-threading the initialization of struct pages in order to improve hotplug performance even further on larger machines. Signed-off-by: Pavel Tatashin Reviewed-by: Ingo Molnar --- drivers/base/node.c | 2 ++ include/linux/memory.h | 1 + mm/memory_hotplug.c | 27 ++++++++------------------- mm/page_alloc.c | 28 ++++++++++------------------ mm/sparse.c | 8 +++++++- 5 files changed, 28 insertions(+), 38 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index d7cfc8d8a5c5..51de4af290ac 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -405,6 +405,8 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid, if (!mem_blk) return -EFAULT; + + mem_blk->nid = nid; if (!node_online(nid)) return 0; diff --git a/include/linux/memory.h b/include/linux/memory.h index 9f8cd856ca1e..31ca3e28b0eb 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -33,6 +33,7 @@ struct memory_block { void *hw; /* optional pointer to fw/hw data */ int (*phys_callback)(struct memory_block *); struct device dev; + int nid; /* NID for this memory block */ }; int arch_get_memory_phys_device(unsigned long start_pfn); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 477e183a4ac7..6a9ba14e18ed 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -250,7 +250,6 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, struct vmem_altmap *altmap, bool want_memblock) { int ret; - int i; if (pfn_valid(phys_start_pfn)) return -EEXIST; @@ -259,23 +258,6 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, if (ret < 0) return ret; - /* - * Make all the pages reserved so that nobody will stumble over half - * initialized state. - * FIXME: We also have to associate it with a node because page_to_nid - * relies on having page with the proper node. - */ - for (i = 0; i < PAGES_PER_SECTION; i++) { - unsigned long pfn = phys_start_pfn + i; - struct page *page; - if (!pfn_valid(pfn)) - continue; - - page = pfn_to_page(pfn); - set_page_node(page, nid); - SetPageReserved(page); - } - if (!want_memblock) return 0; @@ -908,8 +890,15 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ int nid; int ret; struct memory_notify arg; + struct memory_block *mem; + + /* + * We can't use pfn_to_nid() because nid might be stored in struct page + * which is not yet initialized. Instead, we find nid from memory block. + */ + mem = find_memory_block(__pfn_to_section(pfn)); + nid = mem->nid; - nid = pfn_to_nid(pfn); /* associate pfn range with the zone */ zone = move_pfn_range(online_type, nid, pfn, nr_pages); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cb416723538f..8bf3b9c215c1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1181,10 +1181,9 @@ static void free_one_page(struct zone *zone, } static void __meminit __init_single_page(struct page *page, unsigned long pfn, - unsigned long zone, int nid, bool zero) + unsigned long zone, int nid) { - if (zero) - mm_zero_struct_page(page); + mm_zero_struct_page(page); set_page_links(page, zone, nid, pfn); init_page_count(page); page_mapcount_reset(page); @@ -1198,12 +1197,6 @@ static void __meminit __init_single_page(struct page *page, unsigned long pfn, #endif } -static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone, - int nid, bool zero) -{ - return __init_single_page(pfn_to_page(pfn), pfn, zone, nid, zero); -} - #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT static void __meminit init_reserved_page(unsigned long pfn) { @@ -1222,7 +1215,7 @@ static void __meminit init_reserved_page(unsigned long pfn) if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) break; } - __init_single_pfn(pfn, zid, nid, true); + __init_single_page(pfn_to_page(pfn), pfn, zid, nid); } #else static inline void init_reserved_page(unsigned long pfn) @@ -1539,7 +1532,7 @@ static unsigned long __init deferred_init_pages(int nid, int zid, } else { page++; } - __init_single_page(page, pfn, zid, nid, true); + __init_single_page(page, pfn, zid, nid); nr_pages++; } return (nr_pages); @@ -5332,6 +5325,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, pg_data_t *pgdat = NODE_DATA(nid); unsigned long pfn; unsigned long nr_initialised = 0; + struct page *page; #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP struct memblock_region *r = NULL, *tmp; #endif @@ -5393,6 +5387,11 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, #endif not_early: + page = pfn_to_page(pfn); + __init_single_page(page, pfn, zone, nid); + if (context == MEMMAP_HOTPLUG) + SetPageReserved(page); + /* * Mark the block movable so that blocks are reserved for * movable at startup. This will force kernel allocations @@ -5409,15 +5408,8 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, * because this is done early in sparse_add_one_section */ if (!(pfn & (pageblock_nr_pages - 1))) { - struct page *page = pfn_to_page(pfn); - - __init_single_page(page, pfn, zone, nid, - context != MEMMAP_HOTPLUG); set_pageblock_migratetype(page, MIGRATE_MOVABLE); cond_resched(); - } else { - __init_single_pfn(pfn, zone, nid, - context != MEMMAP_HOTPLUG); } } } diff --git a/mm/sparse.c b/mm/sparse.c index 7af5e7a92528..775e1a4fd95e 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -816,7 +816,13 @@ int __meminit sparse_add_one_section(struct pglist_data *pgdat, goto out; } - memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION); +#ifdef CONFIG_DEBUG_VM + /* + * Poison uninitialized struct pages in order to catch invalid flags + * combinations. + */ + memset(memmap, PAGE_POISON_PATTERN, sizeof(struct page) * PAGES_PER_SECTION); +#endif section_mark_present(ms); -- 2.16.2