- 13 Dec, 2012 40 commits
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Jiang Liu authored
Currently a zone's present_pages is calcuated as below, which is inaccurate and may cause trouble to memory hotplug. spanned_pages - absent_pages - memmap_pages - dma_reserve. During fixing bugs caused by inaccurate zone->present_pages, we found zone->present_pages has been abused. The field zone->present_pages may have different meanings in different contexts: 1) pages existing in a zone. 2) pages managed by the buddy system. For more discussions about the issue, please refer to: http://lkml.org/lkml/2012/11/5/866 https://patchwork.kernel.org/patch/1346751/ This patchset tries to introduce a new field named "managed_pages" to struct zone, which counts "pages managed by the buddy system". And revert zone->present_pages to count "physical pages existing in a zone", which also keep in consistence with pgdat->node_present_pages. We will set an initial value for zone->managed_pages in function free_area_init_core() and will adjust it later if the initial value is inaccurate. For DMA/normal zones, the initial value is set to: (spanned_pages - absent_pages - memmap_pages - dma_reserve) Later zone->managed_pages will be adjusted to the accurate value when the bootmem allocator frees all free pages to the buddy system in function free_all_bootmem_node() and free_all_bootmem(). The bootmem allocator doesn't touch highmem pages, so highmem zones' managed_pages is set to the accurate value "spanned_pages - absent_pages" in function free_area_init_core() and won't be updated anymore. This patch also adds a new field "managed_pages" to /proc/zoneinfo and sysrq showmem. [akpm@linux-foundation.org: small comment tweaks] Signed-off-by:
Jiang Liu <jiang.liu@huawei.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Tested-by:
Chris Clayton <chris2553@googlemail.com> Cc: "Rafael J . Wysocki" <rjw@sisk.pl> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan@kernel.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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David Rientjes authored
out_of_memory() is a globally defined function to call the oom killer. x86, sh, and powerpc all use a function of the same name within file scope in their respective fault.c unnecessarily. Inline the functions into the pagefault handlers to clean the code up. Signed-off-by:
David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Reviewed-by:
Michal Hocko <mhocko@suse.cz> Reviewed-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by:
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David Rientjes authored
out_of_memory() will already cause current to schedule if it has not been killed, so doing it again in pagefault_out_of_memory() is redundant. Remove it. Signed-off-by:
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David Rientjes authored
To lock the entire system from parallel oom killing, it's possible to pass in a zonelist with all zones rather than using for_each_populated_zone() for the iteration. This obsoletes try_set_system_oom() and clear_system_oom() so that they can be removed. Signed-off-by:
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Lai Jiangshan authored
Now, memory management can handle movable node or nodes which don't have any normal memory, so we can dynamic configure and add movable node by: online a ZONE_MOVABLE memory from a previous offline node offline the last normal memory which result a non-normal-memory-node movable-node is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). Signed-off-by:
Lai Jiangshan <laijs@cn.fujitsu.com> Tested-by:
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by:
Wen Congyang <wency@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by:
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Lai Jiangshan authored
We need a node which only contains movable memory. This feature is very important for node hotplug. If a node has normal/highmem, the memory may be used by the kernel and can't be offlined. If the node only contains movable memory, we can offline the memory and the node. All are prepared, we can actually introduce N_MEMORY. add CONFIG_MOVABLE_NODE make we can use it for movable-dedicated node [akpm@linux-foundation.org: fix Kconfig text] Signed-off-by:
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David Rientjes authored
While profiling numa/core v16 with cgroup_disable=memory on the command line, I noticed mem_cgroup_count_vm_event() still showed up as high as 0.60% in perftop. This occurs because the function is called extremely often even when memcg is disabled. To fix this, inline the check for mem_cgroup_disabled() so we avoid the unnecessary function call if memcg is disabled. Signed-off-by:
Glauber Costa <glommer@parallels.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Andrew Morton authored
Cc: Glauber Costa <glommer@parallels.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by:
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Joonsoo Kim authored
During reviewing the source code, I found a comment which mention that after f_op->mmap(), vma's start address can be changed. I didn't verify that it is really possible, because there are so many f_op->mmap() implementation. But if there are some mmap() which change vma's start address, it is possible error situation, because we already prepare prev vma, rb_link and rb_parent and these are related to original address. So add WARN_ON_ONCE for finding that this situtation really happens. Signed-off-by:
Joonsoo Kim <js1304@gmail.com> Signed-off-by:
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Greg Thelen authored
Since commit 628f4235 ("memcg: limit change shrink usage") both res_counter_write() and write_strategy_fn have been unused. This patch deletes them both. Signed-off-by:
Greg Thelen <gthelen@google.com> Cc: Glauber Costa <glommer@parallels.com> Cc: Tejun Heo <tj@kernel.org> Acked-by:
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Lai Jiangshan authored
Update nodemasks management for N_MEMORY. [lliubbo@gmail.com: fix build] Signed-off-by:
Bob Liu <lliubbo@gmail.com> Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Since we introduced N_MEMORY, we update the initialization of node_states. Signed-off-by:
Lin Feng <linfeng@cn.fujitsu.com> Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
Hillf Danton <dhillf@gmail.com> Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
Christoph Lameter <cl@linux.com> Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
N_HIGH_MEMORY stands for the nodes that has normal or high memory. N_MEMORY stands for the nodes that has any memory. The code here need to handle with the nodes which have memory, we should use N_MEMORY instead. Signed-off-by:
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Lai Jiangshan authored
We have N_NORMAL_MEMORY for standing for the nodes that have normal memory with zone_type <= ZONE_NORMAL. And we have N_HIGH_MEMORY for standing for the nodes that have normal or high memory. But we don't have any word to stand for the nodes that have *any* memory. And we have N_CPU but without N_MEMORY. Current code reuse the N_HIGH_MEMORY for this purpose because any node which has memory must have high memory or normal memory currently. A) But this reusing is bad for *readability*. Because the name N_HIGH_MEMORY just stands for high or normal: A.example 1) mem_cgroup_nr_lru_pages(): for_each_node_state(nid, N_HIGH_MEMORY) The user will be confused(why this function just counts for high or normal memory node? does it counts for ZONE_MOVABLE's lru pages?) until someone else tell them N_HIGH_MEMORY is reused to stand for nodes that have any memory. A.cont) If we introduce N_MEMORY, we can reduce this confusing AND make the code more clearly: A.example 2) mm/page_cgroup.c use N_HIGH_MEMORY twice: One is in page_cgroup_init(void): for_each_node_state(nid, N_HIGH_MEMORY) { It means if the node have memory, we will allocate page_cgroup map for the node. We should use N_MEMORY instead here to gaim more clearly. The second using is in alloc_page_cgroup(): if (node_state(nid, N_HIGH_MEMORY)) addr = vzalloc_node(size, nid); It means if the node has high or normal memory that can be allocated from kernel. We should keep N_HIGH_MEMORY here, and it will be better if the "any memory" semantic of N_HIGH_MEMORY is removed. B) This reusing is out-dated if we introduce MOVABLE-dedicated node. The MOVABLE-dedicated node should not appear in node_stats[N_HIGH_MEMORY] nor node_stats[N_NORMAL_MEMORY], because MOVABLE-dedicated node has no high or normal memory. In x86_64, N_HIGH_MEMORY=N_NORMAL_MEMORY, if a MOVABLE-dedicated node is in node_stats[N_HIGH_MEMORY], it is also means it is in node_stats[N_NORMAL_MEMORY], it causes SLUB wrong. The slub uses for_each_node_state(nid, N_NORMAL_MEMORY) and creates kmem_cache_node for MOVABLE-dedicated node and cause problem. In one word, we need a N_MEMORY. We just intrude it as an alias to N_HIGH_MEMORY and fix all im-proper usages of N_HIGH_MEMORY in late patches. Signed-off-by: -
Marek Szyprowski authored
__alloc_contig_migrate_range() should use all possible ways to get all the pages migrated from the given memory range, so pruning per-cpu lru lists for all CPUs is required, regadless the cost of such operation. Otherwise some pages which got stuck at per-cpu lru list might get missed by migration procedure causing the contiguous allocation to fail. Reported-by:
SeongHwan Yoon <sunghwan.yun@samsung.com> Signed-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by:
Kyungmin Park <kyungmin.park@samsung.com> Acked-by:
Michal Nazarewicz <mina86@mina86.com> Signed-off-by:
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Thierry Reding authored
compact_capture_page() is only used if compaction is enabled so it should be moved into the corresponding #ifdef. Signed-off-by:
Thierry Reding <thierry.reding@avionic-design.de> Acked-by:
Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by:
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Kirill A. Shutemov authored
pmd value is stable only with mm->page_table_lock taken. After taking the lock we need to check that nobody modified the pmd before changing it. Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: David Rientjes <rientjes@google.com> Reviewed-by:
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Kirill A. Shutemov authored
By default kernel tries to use huge zero page on read page fault. It's possible to disable huge zero page by writing 0 or enable it back by writing 1: echo 0 >/sys/kernel/mm/transparent_hugepage/khugepaged/use_zero_page echo 1 >/sys/kernel/mm/transparent_hugepage/khugepaged/use_zero_page Signed-off-by:
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Kirill A. Shutemov authored
hzp_alloc is incremented every time a huge zero page is successfully allocated. It includes allocations which where dropped due race with other allocation. Note, it doesn't count every map of the huge zero page, only its allocation. hzp_alloc_failed is incremented if kernel fails to allocate huge zero page and falls back to using small pages. Signed-off-by:
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Kirill A. Shutemov authored
H. Peter Anvin doesn't like huge zero page which sticks in memory forever after the first allocation. Here's implementation of lockless refcounting for huge zero page. We have two basic primitives: {get,put}_huge_zero_page(). They manipulate reference counter. If counter is 0, get_huge_zero_page() allocates a new huge page and takes two references: one for caller and one for shrinker. We free the page only in shrinker callback if counter is 1 (only shrinker has the reference). put_huge_zero_page() only decrements counter. Counter is never zero in put_huge_zero_page() since shrinker holds on reference. Freeing huge zero page in shrinker callback helps to avoid frequent allocate-free. Refcounting has cost. On 4 socket machine I observe ~1% slowdown on parallel (40 processes) read page faulting comparing to lazy huge page allocation. I think it's pretty reasonable for synthetic benchmark. [lliubbo@gmail.com: fix mismerge] Signed-off-by: -
Kirill A. Shutemov authored
Instead of allocating huge zero page on hugepage_init() we can postpone it until first huge zero page map. It saves memory if THP is not in use. cmpxchg() is used to avoid race on huge_zero_pfn initialization. Signed-off-by:
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Kirill A. Shutemov authored
All code paths seems covered. Now we can map huge zero page on read page fault. We setup it in do_huge_pmd_anonymous_page() if area around fault address is suitable for THP and we've got read page fault. If we fail to setup huge zero page (ENOMEM) we fallback to handle_pte_fault() as we normally do in THP. Signed-off-by:
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Kirill A. Shutemov authored
We can't split huge zero page itself (and it's bug if we try), but we can split the pmd which points to it. On splitting the pmd we create a table with all ptes set to normal zero page. [akpm@linux-foundation.org: fix build error] Signed-off-by:
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Kirill A. Shutemov authored
Pass vma instead of mm and add address parameter. In most cases we already have vma on the stack. We provides split_huge_page_pmd_mm() for few cases when we have mm, but not vma. This change is preparation to huge zero pmd splitting implementation. Signed-off-by:
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Kirill A. Shutemov authored
mprotect core never tries to make page writable using change_huge_pmd(). Let's add an assert that the assumption is true. It's important to be sure we will not make huge zero page writable. Signed-off-by:
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Kirill A. Shutemov authored
On write access to huge zero page we alloc a new huge page and clear it. If ENOMEM, graceful fallback: we create a new pmd table and set pte around fault address to newly allocated normal (4k) page. All other ptes in the pmd set to normal zero page. Signed-off-by:
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Kirill A. Shutemov authored
It's easy to copy huge zero page. Just set destination pmd to huge zero page. It's safe to copy huge zero page since we have none yet :-p [rientjes@google.com: fix comment] Signed-off-by:
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Kirill A. Shutemov authored
We don't have a mapped page to zap in huge zero page case. Let's just clear pmd and remove it from tlb. Signed-off-by:
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Kirill A. Shutemov authored
During testing I noticed big (up to 2.5 times) memory consumption overhead on some workloads (e.g. ft.A from NPB) if THP is enabled. The main reason for that big difference is lacking zero page in THP case. We have to allocate a real page on read page fault. A program to demonstrate the issue: #include <assert.h> #include <stdlib.h> #include <unistd.h> #define MB 1024*1024 int main(int argc, char **argv) { char *p; int i; posix_memalign((void **)&p, 2 * MB, 200 * MB); for (i = 0; i < 200 * MB; i+= 4096) assert(p[i] == 0); pause(); return 0; } With thp-never RSS is about 400k, but with thp-always it's 200M. After the patcheset thp-always RSS is 400k too. Design overview. Huge zero page (hzp) is a non-movable huge page (2M on x86-64) filled with zeros. The way how we allocate it changes in the patchset: - [01/10] simplest way: hzp allocated on boot time in hugepage_init(); - [09/10] lazy allocation on first use; - [10/10] lockless refcounting + shrinker-reclaimable hzp; We setup it in do_huge_pmd_anonymous_page() if area around fault address is suitable for THP and we've got read page fault. If we fail to setup hzp (ENOMEM) we fallback to handle_pte_fault() as we normally do in THP. On wp fault to hzp we allocate real memory for the huge page and clear it. If ENOMEM, graceful fallback: we create a new pmd table and set pte around fault address to newly allocated normal (4k) page. All other ptes in the pmd set to normal zero page. We cannot split hzp (and it's bug if we try), but we can split the pmd which points to it. On splitting the pmd we create a table with all ptes set to normal zero page. === By hpa's request I've tried alternative approach for hzp implementation (see Virtual huge zero page patchset): pmd table with all entries set to zero page. This way should be more cache friendly, but it increases TLB pressure. The problem with virtual huge zero page: it requires per-arch enabling. We need a way to mark that pmd table has all ptes set to zero page. Some numbers to compare two implementations (on 4s Westmere-EX): Mirobenchmark1 ============== test: posix_memalign((void **)&p, 2 * MB, 8 * GB); for (i = 0; i < 100; i++) { assert(memcmp(p, p + 4*GB, 4*GB) == 0); asm volatile ("": : :"memory"); } hzp: Performance counter stats for './test_memcmp' (5 runs): 32356.272845 task-clock # 0.998 CPUs utilized ( +- 0.13% ) 40 context-switches # 0.001 K/sec ( +- 0.94% ) 0 CPU-migrations # 0.000 K/sec 4,218 page-faults # 0.130 K/sec ( +- 0.00% ) 76,712,481,765 cycles # 2.371 GHz ( +- 0.13% ) [83.31%] 36,279,577,636 stalled-cycles-frontend # 47.29% frontend cycles idle ( +- 0.28% ) [83.35%] 1,684,049,110 stalled-cycles-backend # 2.20% backend cycles idle ( +- 2.96% ) [66.67%] 134,355,715,816 instructions # 1.75 insns per cycle # 0.27 stalled cycles per insn ( +- 0.10% ) [83.35%] 13,526,169,702 branches # 418.039 M/sec ( +- 0.10% ) [83.31%] 1,058,230 branch-misses # 0.01% of all branches ( +- 0.91% ) [83.36%] 32.413866442 seconds time elapsed ( +- 0.13% ) vhzp: Performance counter stats for './test_memcmp' (5 runs): 30327.183829 task-clock # 0.998 CPUs utilized ( +- 0.13% ) 38 context-switches # 0.001 K/sec ( +- 1.53% ) 0 CPU-migrations # 0.000 K/sec 4,218 page-faults # 0.139 K/sec ( +- 0.01% ) 71,964,773,660 cycles # 2.373 GHz ( +- 0.13% ) [83.35%] 31,191,284,231 stalled-cycles-frontend # 43.34% frontend cycles idle ( +- 0.40% ) [83.32%] 773,484,474 stalled-cycles-backend # 1.07% backend cycles idle ( +- 6.61% ) [66.67%] 134,982,215,437 instructions # 1.88 insns per cycle # 0.23 stalled cycles per insn ( +- 0.11% ) [83.32%] 13,509,150,683 branches # 445.447 M/sec ( +- 0.11% ) [83.34%] 1,017,667 branch-misses # 0.01% of all branches ( +- 1.07% ) [83.32%] 30.381324695 seconds time elapsed ( +- 0.13% ) Mirobenchmark2 ============== test: posix_memalign((void **)&p, 2 * MB, 8 * GB); for (i = 0; i < 1000; i++) { char *_p = p; while (_p < p+4*GB) { assert(*_p == *(_p+4*GB)); _p += 4096; asm volatile ("": : :"memory"); } } hzp: Performance counter stats for 'taskset -c 0 ./test_memcmp2' (5 runs): 3505.727639 task-clock # 0.998 CPUs utilized ( +- 0.26% ) 9 context-switches # 0.003 K/sec ( +- 4.97% ) 4,384 page-faults # 0.001 M/sec ( +- 0.00% ) 8,318,482,466 cycles # 2.373 GHz ( +- 0.26% ) [33.31%] 5,134,318,786 stalled-cycles-frontend # 61.72% frontend cycles idle ( +- 0.42% ) [33.32%] 2,193,266,208 stalled-cycles-backend # 26.37% backend cycles idle ( +- 5.51% ) [33.33%] 9,494,670,537 instructions # 1.14 insns per cycle # 0.54 stalled cycles per insn ( +- 0.13% ) [41.68%] 2,108,522,738 branches # 601.451 M/sec ( +- 0.09% ) [41.68%] 158,746 branch-misses # 0.01% of all branches ( +- 1.60% ) [41.71%] 3,168,102,115 L1-dcache-loads # 903.693 M/sec ( +- 0.11% ) [41.70%] 1,048,710,998 L1-dcache-misses # 33.10% of all L1-dcache hits ( +- 0.11% ) [41.72%] 1,047,699,685 LLC-load # 298.854 M/sec ( +- 0.03% ) [33.38%] 2,287 LLC-misses # 0.00% of all LL-cache hits ( +- 8.27% ) [33.37%] 3,166,187,367 dTLB-loads # 903.147 M/sec ( +- 0.02% ) [33.35%] 4,266,538 dTLB-misses # 0.13% of all dTLB cache hits ( +- 0.03% ) [33.33%] 3.513339813 seconds time elapsed ( +- 0.26% ) vhzp: Performance counter stats for 'taskset -c 0 ./test_memcmp2' (5 runs): 27313.891128 task-clock # 0.998 CPUs utilized ( +- 0.24% ) 62 context-switches # 0.002 K/sec ( +- 0.61% ) 4,384 page-faults # 0.160 K/sec ( +- 0.01% ) 64,747,374,606 cycles # 2.370 GHz ( +- 0.24% ) [33.33%] 61,341,580,278 stalled-cycles-frontend # 94.74% frontend cycles idle ( +- 0.26% ) [33.33%] 56,702,237,511 stalled-cycles-backend # 87.57% backend cycles idle ( +- 0.07% ) [33.33%] 10,033,724,846 instructions # 0.15 insns per cycle # 6.11 stalled cycles per insn ( +- 0.09% ) [41.65%] 2,190,424,932 branches # 80.195 M/sec ( +- 0.12% ) [41.66%] 1,028,630 branch-misses # 0.05% of all branches ( +- 1.50% ) [41.66%] 3,302,006,540 L1-dcache-loads # 120.891 M/sec ( +- 0.11% ) [41.68%] 271,374,358 L1-dcache-misses # 8.22% of all L1-dcache hits ( +- 0.04% ) [41.66%] 20,385,476 LLC-load # 0.746 M/sec ( +- 1.64% ) [33.34%] 76,754 LLC-misses # 0.38% of all LL-cache hits ( +- 2.35% ) [33.34%] 3,309,927,290 dTLB-loads # 121.181 M/sec ( +- 0.03% ) [33.34%] 2,098,967,427 dTLB-misses # 63.41% of all dTLB cache hits ( +- 0.03% ) [33.34%] 27.364448741 seconds time elapsed ( +- 0.24% ) === I personally prefer implementation present in this patchset. It doesn't touch arch-specific code. This patch: Huge zero page (hzp) is a non-movable huge page (2M on x86-64) filled with zeros. For now let's allocate the page on hugepage_init(). We'll switch to lazy allocation later. We are not going to map the huge zero page until we can handle it properly on all code paths. is_huge_zero_{pfn,pmd}() functions will be used by following patches to check whether the pfn/pmd is huge zero page. Signed-off-by: -
Joonsoo Kim authored
The name of this function is not suitable, and removing the function and open-coding it into each call sites makes the code more understandable. Additionally, we shouldn't do an allocation from bootmem when slab_is_available(), so directly return kmalloc()'s return value. Signed-off-by:
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