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author | Pavel Tatashin <pasha.tatashin@oracle.com> | 2018-04-05 16:23:00 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:25 -0700 |
commit | d0dc12e86b3197a14a908d4fe7cb35b73dda82b5 (patch) | |
tree | 28bd3b5c716e3e1c04fab511c3a41033bdc85993 | |
parent | fc44f7f9231a73821fc858f5bc48883a9e78f6de (diff) | |
download | linux-stable-d0dc12e86b3197a14a908d4fe7cb35b73dda82b5.tar.gz linux-stable-d0dc12e86b3197a14a908d4fe7cb35b73dda82b5.tar.bz2 linux-stable-d0dc12e86b3197a14a908d4fe7cb35b73dda82b5.zip |
mm/memory_hotplug: optimize memory hotplug
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.
[pasha.tatashin@oracle.com: v5]
Link: http://lkml.kernel.org/r/20180228030308.1116-7-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180215165920.8570-7-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | drivers/base/node.c | 2 | ||||
-rw-r--r-- | include/linux/memory.h | 1 | ||||
-rw-r--r-- | mm/memory_hotplug.c | 27 | ||||
-rw-r--r-- | mm/page_alloc.c | 28 | ||||
-rw-r--r-- | mm/sparse.c | 8 |
5 files changed, 28 insertions, 38 deletions
diff --git a/drivers/base/node.c b/drivers/base/node.c index 92b00a7e6a02..7a3a580821e0 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -407,6 +407,8 @@ 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 3183eb2f579c..a3e2ba4f76bb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1143,10 +1143,9 @@ 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); @@ -1160,12 +1159,6 @@ 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) { @@ -1184,7 +1177,7 @@ 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) @@ -1501,7 +1494,7 @@ 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); @@ -5434,6 +5427,7 @@ 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 @@ -5486,6 +5480,11 @@ 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 @@ -5502,15 +5501,8 @@ not_early: * 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 58cab483e81b..62eef264a7bd 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -779,7 +779,13 @@ 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); |