Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932130Ab3DDARU (ORCPT ); Wed, 3 Apr 2013 20:17:20 -0400 Received: from mail-ie0-f172.google.com ([209.85.223.172]:34760 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757659Ab3DDART (ORCPT ); Wed, 3 Apr 2013 20:17:19 -0400 Message-ID: <515CC684.9050004@gmail.com> Date: Thu, 04 Apr 2013 08:17:08 +0800 From: Simon Jeons User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Cliff Wickman CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, wli@holomorphy.com Subject: Re: [PATCH] mm, x86: no zeroing of hugetlbfs pages at boot References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 14832 Lines: 405 On 03/07/2013 05:50 AM, Cliff Wickman wrote: > From: Cliff Wickman > > Allocating a large number of 1GB hugetlbfs pages at boot takes a > very long time. > > Large system sites would at times like to allocate a very large amount of > memory as 1GB pages. They would put this on the kernel boot line: > default_hugepagesz=1G hugepagesz=1G hugepages=4096 > [Dynamic allocation of 1G pages is not an option, as zone pages only go > up to MAX_ORDER, and MAX_ORDER cannot exceed the section size.] > > Each page is zeroed as it is allocated, and all allocation is done by > cpu 0, as this path is early in boot: How you confirm they are done by cpu 0? just cpu 0 works during boot? > start_kernel > kernel_init > do_pre_smp_initcalls > hugetlb_init > hugetlb_init_hstates > hugetlb_hstate_alloc_pages > > Zeroing remote (offnode) memory takes ~1GB/sec (and most memory is offnode > on large numa systems). > This estimate is approximate (it depends on core frequency & number of hops > to remote memory) but should be within a factor of 2 on most systems. > A benchmark attempting to reserve a TB for 1GB pages would thus require > ~1000 seconds of boot time just for this allocating. 32TB would take 8 hours. > > I propose passing a flag to the early allocator to indicate that no zeroing > of a page should be done. The 'no zeroing' flag would have to be passed > down this code path: > > hugetlb_hstate_alloc_pages > alloc_bootmem_huge_page > __alloc_bootmem_node_nopanic NO_ZERO (nobootmem.c) > __alloc_memory_core_early NO_ZERO > if (!(flags & NO_ZERO)) > memset(ptr, 0, size); > > Or this path if CONFIG_NO_BOOTMEM is not set: > > hugetlb_hstate_alloc_pages > alloc_bootmem_huge_page > __alloc_bootmem_node_nopanic NO_ZERO (bootmem.c) > alloc_bootmem_core NO_ZERO > if (!(flags & NO_ZERO)) > memset(region, 0, size); > __alloc_bootmem_nopanic NO_ZERO > ___alloc_bootmem_nopanic NO_ZERO > alloc_bootmem_core NO_ZERO > if (!(flags & NO_ZERO)) > memset(region, 0, size); > > Signed-off-by: Cliff Wickman > > --- > arch/x86/kernel/setup_percpu.c | 4 ++-- > include/linux/bootmem.h | 23 ++++++++++++++++------- > mm/bootmem.c | 12 +++++++----- > mm/hugetlb.c | 3 ++- > mm/nobootmem.c | 41 +++++++++++++++++++++++------------------ > mm/page_cgroup.c | 2 +- > mm/sparse.c | 2 +- > 7 files changed, 52 insertions(+), 35 deletions(-) > > Index: linux/include/linux/bootmem.h > =================================================================== > --- linux.orig/include/linux/bootmem.h > +++ linux/include/linux/bootmem.h > @@ -8,6 +8,11 @@ > #include > > /* > + * allocation flags > + */ > +#define NO_ZERO 0x00000001 > + > +/* > * simple boot-time physical memory area allocator. > */ > > @@ -79,7 +84,8 @@ extern void *__alloc_bootmem(unsigned lo > unsigned long goal); > extern void *__alloc_bootmem_nopanic(unsigned long size, > unsigned long align, > - unsigned long goal); > + unsigned long goal, > + u32 flags); > extern void *__alloc_bootmem_node(pg_data_t *pgdat, > unsigned long size, > unsigned long align, > @@ -91,12 +97,14 @@ void *__alloc_bootmem_node_high(pg_data_ > extern void *__alloc_bootmem_node_nopanic(pg_data_t *pgdat, > unsigned long size, > unsigned long align, > - unsigned long goal); > + unsigned long goal, > + u32 flags); > void *___alloc_bootmem_node_nopanic(pg_data_t *pgdat, > unsigned long size, > unsigned long align, > unsigned long goal, > - unsigned long limit); > + unsigned long limit, > + u32 flags); > extern void *__alloc_bootmem_low(unsigned long size, > unsigned long align, > unsigned long goal); > @@ -120,19 +128,20 @@ extern void *__alloc_bootmem_low_node(pg > #define alloc_bootmem_align(x, align) \ > __alloc_bootmem(x, align, BOOTMEM_LOW_LIMIT) > #define alloc_bootmem_nopanic(x) \ > - __alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT) > + __alloc_bootmem_nopanic(x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT, 0) > #define alloc_bootmem_pages(x) \ > __alloc_bootmem(x, PAGE_SIZE, BOOTMEM_LOW_LIMIT) > #define alloc_bootmem_pages_nopanic(x) \ > - __alloc_bootmem_nopanic(x, PAGE_SIZE, BOOTMEM_LOW_LIMIT) > + __alloc_bootmem_nopanic(x, PAGE_SIZE, BOOTMEM_LOW_LIMIT, 0) > #define alloc_bootmem_node(pgdat, x) \ > __alloc_bootmem_node(pgdat, x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT) > #define alloc_bootmem_node_nopanic(pgdat, x) \ > - __alloc_bootmem_node_nopanic(pgdat, x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT) > + __alloc_bootmem_node_nopanic(pgdat, x, SMP_CACHE_BYTES, \ > + BOOTMEM_LOW_LIMIT, 0) > #define alloc_bootmem_pages_node(pgdat, x) \ > __alloc_bootmem_node(pgdat, x, PAGE_SIZE, BOOTMEM_LOW_LIMIT) > #define alloc_bootmem_pages_node_nopanic(pgdat, x) \ > - __alloc_bootmem_node_nopanic(pgdat, x, PAGE_SIZE, BOOTMEM_LOW_LIMIT) > + __alloc_bootmem_node_nopanic(pgdat, x, PAGE_SIZE, BOOTMEM_LOW_LIMIT, 0) > > #define alloc_bootmem_low(x) \ > __alloc_bootmem_low(x, SMP_CACHE_BYTES, 0) > Index: linux/arch/x86/kernel/setup_percpu.c > =================================================================== > --- linux.orig/arch/x86/kernel/setup_percpu.c > +++ linux/arch/x86/kernel/setup_percpu.c > @@ -104,14 +104,14 @@ static void * __init pcpu_alloc_bootmem( > void *ptr; > > if (!node_online(node) || !NODE_DATA(node)) { > - ptr = __alloc_bootmem_nopanic(size, align, goal); > + ptr = __alloc_bootmem_nopanic(size, align, goal, 0); > pr_info("cpu %d has no node %d or node-local memory\n", > cpu, node); > pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n", > cpu, size, __pa(ptr)); > } else { > ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node), > - size, align, goal); > + size, align, goal, 0); > pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n", > cpu, size, node, __pa(ptr)); > } > Index: linux/mm/nobootmem.c > =================================================================== > --- linux.orig/mm/nobootmem.c > +++ linux/mm/nobootmem.c > @@ -33,7 +33,7 @@ unsigned long min_low_pfn; > unsigned long max_pfn; > > static void * __init __alloc_memory_core_early(int nid, u64 size, u64 align, > - u64 goal, u64 limit) > + u64 goal, u64 limit, u32 flags) > { > void *ptr; > u64 addr; > @@ -46,7 +46,8 @@ static void * __init __alloc_memory_core > return NULL; > > ptr = phys_to_virt(addr); > - memset(ptr, 0, size); > + if (!(flags & NO_ZERO)) > + memset(ptr, 0, size); > memblock_reserve(addr, size); > /* > * The min_count is set to 0 so that bootmem allocated blocks > @@ -208,7 +209,8 @@ void __init free_bootmem(unsigned long a > static void * __init ___alloc_bootmem_nopanic(unsigned long size, > unsigned long align, > unsigned long goal, > - unsigned long limit) > + unsigned long limit, > + u32 flags) > { > void *ptr; > > @@ -217,7 +219,8 @@ static void * __init ___alloc_bootmem_no > > restart: > > - ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, goal, limit); > + ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, goal, > + limit, 0); > > if (ptr) > return ptr; > @@ -244,17 +247,17 @@ restart: > * Returns NULL on failure. > */ > void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, > - unsigned long goal) > + unsigned long goal, u32 flags) > { > unsigned long limit = -1UL; > > - return ___alloc_bootmem_nopanic(size, align, goal, limit); > + return ___alloc_bootmem_nopanic(size, align, goal, limit, flags); > } > > static void * __init ___alloc_bootmem(unsigned long size, unsigned long align, > - unsigned long goal, unsigned long limit) > + unsigned long goal, unsigned long limit, u32 flags) > { > - void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit); > + void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit, flags); > > if (mem) > return mem; > @@ -284,25 +287,26 @@ void * __init __alloc_bootmem(unsigned l > { > unsigned long limit = -1UL; > > - return ___alloc_bootmem(size, align, goal, limit); > + return ___alloc_bootmem(size, align, goal, limit, 0); > } > > void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat, > unsigned long size, > unsigned long align, > unsigned long goal, > - unsigned long limit) > + unsigned long limit, > + u32 flags) > { > void *ptr; > > again: > ptr = __alloc_memory_core_early(pgdat->node_id, size, align, > - goal, limit); > + goal, limit, flags); > if (ptr) > return ptr; > > ptr = __alloc_memory_core_early(MAX_NUMNODES, size, align, > - goal, limit); > + goal, limit, flags); > if (ptr) > return ptr; > > @@ -315,12 +319,13 @@ again: > } > > void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size, > - unsigned long align, unsigned long goal) > + unsigned long align, unsigned long goal, u32 flags) > { > if (WARN_ON_ONCE(slab_is_available())) > return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id); > > - return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0); > + return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, > + 0, flags); > } > > void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size, > @@ -329,7 +334,7 @@ void * __init ___alloc_bootmem_node(pg_d > { > void *ptr; > > - ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, limit); > + ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, limit, 0); > if (ptr) > return ptr; > > @@ -354,7 +359,7 @@ void * __init ___alloc_bootmem_node(pg_d > * The function panics if the request can not be satisfied. > */ > void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size, > - unsigned long align, unsigned long goal) > + unsigned long align, unsigned long goal) > { > if (WARN_ON_ONCE(slab_is_available())) > return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id); > @@ -388,7 +393,7 @@ void * __init __alloc_bootmem_node_high( > void * __init __alloc_bootmem_low(unsigned long size, unsigned long align, > unsigned long goal) > { > - return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT); > + return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT, 0); > } > > void * __init __alloc_bootmem_low_nopanic(unsigned long size, > @@ -396,7 +401,7 @@ void * __init __alloc_bootmem_low_nopani > unsigned long goal) > { > return ___alloc_bootmem_nopanic(size, align, goal, > - ARCH_LOW_ADDRESS_LIMIT); > + ARCH_LOW_ADDRESS_LIMIT, 0); > } > > /** > Index: linux/mm/sparse.c > =================================================================== > --- linux.orig/mm/sparse.c > +++ linux/mm/sparse.c > @@ -281,7 +281,7 @@ sparse_early_usemaps_alloc_pgdat_section > nid = early_pfn_to_nid(goal >> PAGE_SHIFT); > again: > p = ___alloc_bootmem_node_nopanic(NODE_DATA(nid), size, > - SMP_CACHE_BYTES, goal, limit); > + SMP_CACHE_BYTES, goal, limit, 0); > if (!p && limit) { > limit = 0; > goto again; > Index: linux/mm/hugetlb.c > =================================================================== > --- linux.orig/mm/hugetlb.c > +++ linux/mm/hugetlb.c > @@ -1188,7 +1188,8 @@ int __weak alloc_bootmem_huge_page(struc > addr = __alloc_bootmem_node_nopanic( > NODE_DATA(hstate_next_node_to_alloc(h, > &node_states[N_MEMORY])), > - huge_page_size(h), huge_page_size(h), 0); > + huge_page_size(h), huge_page_size(h), > + 0, NO_ZERO); > > if (addr) { > /* > Index: linux/mm/bootmem.c > =================================================================== > --- linux.orig/mm/bootmem.c > +++ linux/mm/bootmem.c > @@ -660,7 +660,7 @@ restart: > * Returns NULL on failure. > */ > void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, > - unsigned long goal) > + unsigned long goal, u32 flags) > { > unsigned long limit = 0; > > @@ -705,7 +705,8 @@ void * __init __alloc_bootmem(unsigned l > > void * __init ___alloc_bootmem_node_nopanic(pg_data_t *pgdat, > unsigned long size, unsigned long align, > - unsigned long goal, unsigned long limit) > + unsigned long goal, unsigned long limit, > + u32 flags) > { > void *ptr; > > @@ -734,12 +735,13 @@ again: > } > > void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size, > - unsigned long align, unsigned long goal) > + unsigned long align, unsigned long goal, u32 flags) > { > if (WARN_ON_ONCE(slab_is_available())) > return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id); > > - return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0); > + return ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, > + 0, flags); > } > > void * __init ___alloc_bootmem_node(pg_data_t *pgdat, unsigned long size, > @@ -748,7 +750,7 @@ void * __init ___alloc_bootmem_node(pg_d > { > void *ptr; > > - ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0); > + ptr = ___alloc_bootmem_node_nopanic(pgdat, size, align, goal, 0, 0); > if (ptr) > return ptr; > > Index: linux/mm/page_cgroup.c > =================================================================== > --- linux.orig/mm/page_cgroup.c > +++ linux/mm/page_cgroup.c > @@ -55,7 +55,7 @@ static int __init alloc_node_page_cgroup > table_size = sizeof(struct page_cgroup) * nr_pages; > > base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), > - table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); > + table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS), 0); > if (!base) > return -ENOMEM; > NODE_DATA(nid)->node_page_cgroup = base; > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/