From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Pavel Tatashin To: linux-mm@kvack.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 2/4] mm: Zeroing hash tables in allocator Date: Thu, 2 Mar 2017 00:33:43 -0500 Message-Id: <1488432825-92126-3-git-send-email-pasha.tatashin@oracle.com> In-Reply-To: <1488432825-92126-1-git-send-email-pasha.tatashin@oracle.com> References: <1488432825-92126-1-git-send-email-pasha.tatashin@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: Add a new flag HASH_ZERO which when provided grantees that the hash table that is returned by alloc_large_system_hash() is zeroed. In most cases that is what is needed by the caller. Use page level allocator's __GFP_ZERO flags to zero the memory. It is using memset() which is efficient method to zero memory and is optimized for most platforms. Signed-off-by: Pavel Tatashin Reviewed-by: Babu Moger --- include/linux/bootmem.h | 1 + mm/page_alloc.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h index 962164d..e223d91 100644 --- a/include/linux/bootmem.h +++ b/include/linux/bootmem.h @@ -358,6 +358,7 @@ static inline void __init memblock_free_late( #define HASH_EARLY 0x00000001 /* Allocating during early boot? */ #define HASH_SMALL 0x00000002 /* sub-page allocation allowed, min * shift passed via *_hash_shift */ +#define HASH_ZERO 0x00000004 /* Zero allocated hash table */ /* Only NUMA needs hash distribution. 64bit NUMA architectures have * sufficient vmalloc space. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a7a6aac..1b0f7a4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7142,6 +7142,7 @@ static unsigned long __init arch_reserved_kernel_pages(void) unsigned long long max = high_limit; unsigned long log2qty, size; void *table = NULL; + gfp_t gfp_flags; /* allow the kernel cmdline to have a say */ if (!numentries) { @@ -7186,12 +7187,17 @@ static unsigned long __init arch_reserved_kernel_pages(void) log2qty = ilog2(numentries); + /* + * memblock allocator returns zeroed memory already, so HASH_ZERO is + * currently not used when HASH_EARLY is specified. + */ + gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; do { size = bucketsize << log2qty; if (flags & HASH_EARLY) table = memblock_virt_alloc_nopanic(size, 0); else if (hashdist) - table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); + table = __vmalloc(size, gfp_flags, PAGE_KERNEL); else { /* * If bucketsize is not a power-of-two, we may free @@ -7199,8 +7205,8 @@ static unsigned long __init arch_reserved_kernel_pages(void) * alloc_pages_exact() automatically does */ if (get_order(size) < MAX_ORDER) { - table = alloc_pages_exact(size, GFP_ATOMIC); - kmemleak_alloc(table, size, 1, GFP_ATOMIC); + table = alloc_pages_exact(size, gfp_flags); + kmemleak_alloc(table, size, 1, gfp_flags); } } } while (!table && size > PAGE_SIZE && --log2qty); -- 1.7.1 -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Tatashin Date: Thu, 02 Mar 2017 05:33:43 +0000 Subject: [PATCH v3 2/4] mm: Zeroing hash tables in allocator Message-Id: <1488432825-92126-3-git-send-email-pasha.tatashin@oracle.com> List-Id: References: <1488432825-92126-1-git-send-email-pasha.tatashin@oracle.com> In-Reply-To: <1488432825-92126-1-git-send-email-pasha.tatashin@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-mm@kvack.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org Add a new flag HASH_ZERO which when provided grantees that the hash table that is returned by alloc_large_system_hash() is zeroed. In most cases that is what is needed by the caller. Use page level allocator's __GFP_ZERO flags to zero the memory. It is using memset() which is efficient method to zero memory and is optimized for most platforms. Signed-off-by: Pavel Tatashin Reviewed-by: Babu Moger --- include/linux/bootmem.h | 1 + mm/page_alloc.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h index 962164d..e223d91 100644 --- a/include/linux/bootmem.h +++ b/include/linux/bootmem.h @@ -358,6 +358,7 @@ static inline void __init memblock_free_late( #define HASH_EARLY 0x00000001 /* Allocating during early boot? */ #define HASH_SMALL 0x00000002 /* sub-page allocation allowed, min * shift passed via *_hash_shift */ +#define HASH_ZERO 0x00000004 /* Zero allocated hash table */ /* Only NUMA needs hash distribution. 64bit NUMA architectures have * sufficient vmalloc space. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a7a6aac..1b0f7a4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7142,6 +7142,7 @@ static unsigned long __init arch_reserved_kernel_pages(void) unsigned long long max = high_limit; unsigned long log2qty, size; void *table = NULL; + gfp_t gfp_flags; /* allow the kernel cmdline to have a say */ if (!numentries) { @@ -7186,12 +7187,17 @@ static unsigned long __init arch_reserved_kernel_pages(void) log2qty = ilog2(numentries); + /* + * memblock allocator returns zeroed memory already, so HASH_ZERO is + * currently not used when HASH_EARLY is specified. + */ + gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC; do { size = bucketsize << log2qty; if (flags & HASH_EARLY) table = memblock_virt_alloc_nopanic(size, 0); else if (hashdist) - table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); + table = __vmalloc(size, gfp_flags, PAGE_KERNEL); else { /* * If bucketsize is not a power-of-two, we may free @@ -7199,8 +7205,8 @@ static unsigned long __init arch_reserved_kernel_pages(void) * alloc_pages_exact() automatically does */ if (get_order(size) < MAX_ORDER) { - table = alloc_pages_exact(size, GFP_ATOMIC); - kmemleak_alloc(table, size, 1, GFP_ATOMIC); + table = alloc_pages_exact(size, gfp_flags); + kmemleak_alloc(table, size, 1, gfp_flags); } } } while (!table && size > PAGE_SIZE && --log2qty); -- 1.7.1