From 42d7395feb56f0655cd8b68e06fc6063823449f8 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 11 Dec 2012 16:01:34 -0800 Subject: mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB There was some desire in large applications using MAP_HUGETLB or SHM_HUGETLB to use 1GB huge pages on some mappings, and stay with 2MB on others. This is useful together with NUMA policy: use 2MB interleaving on some mappings, but 1GB on local mappings. This patch extends the IPC/SHM syscall interfaces slightly to allow specifying the page size. It borrows some upper bits in the existing flag arguments and allows encoding the log of the desired page size in addition to the *_HUGETLB flag. When 0 is specified the default size is used, this makes the change fully compatible. Extending the internal hugetlb code to handle this is straight forward. Instead of a single mount it just keeps an array of them and selects the right mount based on the specified page size. When no page size is specified it uses the mount of the default page size. The change is not visible in /proc/mounts because internal mounts don't appear there. It also has very little overhead: the additional mounts just consume a super block, but not more memory when not used. I also exported the new flags to the user headers (they were previously under __KERNEL__). Right now only symbols for x86 and some other architecture for 1GB and 2MB are defined. The interface should already work for all other architectures though. Only architectures that define multiple hugetlb sizes actually need it (that is currently x86, tile, powerpc). However tile and powerpc have user configurable hugetlb sizes, so it's not easy to add defines. A program on those architectures would need to query sysfs and use the appropiate log2. [akpm@linux-foundation.org: cleanups] [rientjes@google.com: fix build] [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Andi Kleen Cc: Michael Kerrisk Acked-by: Rik van Riel Acked-by: KAMEZAWA Hiroyuki Cc: Hillf Danton Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 63 +++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 50 insertions(+), 13 deletions(-) (limited to 'fs/hugetlbfs/inode.c') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index c5bc355d824..21b8a487523 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -923,7 +923,7 @@ static struct file_system_type hugetlbfs_fs_type = { .kill_sb = kill_litter_super, }; -static struct vfsmount *hugetlbfs_vfsmount; +static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE]; static int can_do_hugetlb_shm(void) { @@ -932,9 +932,22 @@ static int can_do_hugetlb_shm(void) return capable(CAP_IPC_LOCK) || in_group_p(shm_group); } +static int get_hstate_idx(int page_size_log) +{ + struct hstate *h; + + if (!page_size_log) + return default_hstate_idx; + h = size_to_hstate(1 << page_size_log); + if (!h) + return -1; + return h - hstates; +} + struct file *hugetlb_file_setup(const char *name, unsigned long addr, size_t size, vm_flags_t acctflag, - struct user_struct **user, int creat_flags) + struct user_struct **user, + int creat_flags, int page_size_log) { int error = -ENOMEM; struct file *file; @@ -944,9 +957,14 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr, struct qstr quick_string; struct hstate *hstate; unsigned long num_pages; + int hstate_idx; + + hstate_idx = get_hstate_idx(page_size_log); + if (hstate_idx < 0) + return ERR_PTR(-ENODEV); *user = NULL; - if (!hugetlbfs_vfsmount) + if (!hugetlbfs_vfsmount[hstate_idx]) return ERR_PTR(-ENOENT); if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) { @@ -963,7 +981,7 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr, } } - root = hugetlbfs_vfsmount->mnt_root; + root = hugetlbfs_vfsmount[hstate_idx]->mnt_root; quick_string.name = name; quick_string.len = strlen(quick_string.name); quick_string.hash = 0; @@ -971,7 +989,7 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr, if (!path.dentry) goto out_shm_unlock; - path.mnt = mntget(hugetlbfs_vfsmount); + path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]); error = -ENOSPC; inode = hugetlbfs_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0); if (!inode) @@ -1011,8 +1029,9 @@ out_shm_unlock: static int __init init_hugetlbfs_fs(void) { + struct hstate *h; int error; - struct vfsmount *vfsmount; + int i; error = bdi_init(&hugetlbfs_backing_dev_info); if (error) @@ -1029,14 +1048,26 @@ static int __init init_hugetlbfs_fs(void) if (error) goto out; - vfsmount = kern_mount(&hugetlbfs_fs_type); + i = 0; + for_each_hstate(h) { + char buf[50]; + unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10); - if (!IS_ERR(vfsmount)) { - hugetlbfs_vfsmount = vfsmount; - return 0; - } + snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb); + hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type, + buf); - error = PTR_ERR(vfsmount); + if (IS_ERR(hugetlbfs_vfsmount[i])) { + pr_err("hugetlb: Cannot mount internal hugetlbfs for " + "page size %uK", ps_kb); + error = PTR_ERR(hugetlbfs_vfsmount[i]); + hugetlbfs_vfsmount[i] = NULL; + } + i++; + } + /* Non default hstates are optional */ + if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx])) + return 0; out: kmem_cache_destroy(hugetlbfs_inode_cachep); @@ -1047,13 +1078,19 @@ static int __init init_hugetlbfs_fs(void) static void __exit exit_hugetlbfs_fs(void) { + struct hstate *h; + int i; + + /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(hugetlbfs_inode_cachep); - kern_unmount(hugetlbfs_vfsmount); + i = 0; + for_each_hstate(h) + kern_unmount(hugetlbfs_vfsmount[i++]); unregister_filesystem(&hugetlbfs_fs_type); bdi_destroy(&hugetlbfs_backing_dev_info); } -- cgit v1.2.3-18-g5258 From 0865935598bb112a02f40017e8aaa6bce8577f23 Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Tue, 11 Dec 2012 16:02:00 -0800 Subject: mm: use vm_unmapped_area() in hugetlbfs Update the hugetlb_get_unmapped_area function to make use of vm_unmapped_area() instead of implementing a brute force search. Signed-off-by: Michel Lespinasse Reviewed-by: Rik van Riel Cc: Hugh Dickins Cc: Russell King Cc: Ralf Baechle Cc: Paul Mundt Cc: "David S. Miller" Cc: Chris Metcalf Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 42 ++++++++---------------------------------- 1 file changed, 8 insertions(+), 34 deletions(-) (limited to 'fs/hugetlbfs/inode.c') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 21b8a487523..47e6e2f21e2 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -151,8 +151,8 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; - unsigned long start_addr; struct hstate *h = hstate_file(file); + struct vm_unmapped_area_info info; if (len & ~huge_page_mask(h)) return -EINVAL; @@ -173,39 +173,13 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, return addr; } - if (len > mm->cached_hole_size) - start_addr = mm->free_area_cache; - else { - start_addr = TASK_UNMAPPED_BASE; - mm->cached_hole_size = 0; - } - -full_search: - addr = ALIGN(start_addr, huge_page_size(h)); - - for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { - /* At this point: (!vma || addr < vma->vm_end). */ - if (TASK_SIZE - len < addr) { - /* - * Start a new search - just in case we missed - * some holes. - */ - if (start_addr != TASK_UNMAPPED_BASE) { - start_addr = TASK_UNMAPPED_BASE; - mm->cached_hole_size = 0; - goto full_search; - } - return -ENOMEM; - } - - if (!vma || addr + len <= vma->vm_start) { - mm->free_area_cache = addr + len; - return addr; - } - if (addr + mm->cached_hole_size < vma->vm_start) - mm->cached_hole_size = vma->vm_start - addr; - addr = ALIGN(vma->vm_end, huge_page_size(h)); - } + info.flags = 0; + info.length = len; + info.low_limit = TASK_UNMAPPED_BASE; + info.high_limit = TASK_SIZE; + info.align_mask = PAGE_MASK & ~huge_page_mask(h); + info.align_offset = 0; + return vm_unmapped_area(&info); } #endif -- cgit v1.2.3-18-g5258 From 78bd52097d04205a33a8014a1b8ac01cf1ae9d06 Mon Sep 17 00:00:00 2001 From: Rafael Aquini Date: Tue, 11 Dec 2012 16:02:31 -0800 Subject: mm: adjust address_space_operations.migratepage() return code Memory fragmentation introduced by ballooning might reduce significantly the number of 2MB contiguous memory blocks that can be used within a guest, thus imposing performance penalties associated with the reduced number of transparent huge pages that could be used by the guest workload. This patch-set follows the main idea discussed at 2012 LSFMMS session: "Ballooning for transparent huge pages" -- http://lwn.net/Articles/490114/ to introduce the required changes to the virtio_balloon driver, as well as the changes to the core compaction & migration bits, in order to make those subsystems aware of ballooned pages and allow memory balloon pages become movable within a guest, thus avoiding the aforementioned fragmentation issue Following are numbers that prove this patch benefits on allowing compaction to be more effective at memory ballooned guests. Results for STRESS-HIGHALLOC benchmark, from Mel Gorman's mmtests suite, running on a 4gB RAM KVM guest which was ballooning 512mB RAM in 64mB chunks, at every minute (inflating/deflating), while test was running: ===BEGIN stress-highalloc STRESS-HIGHALLOC highalloc-3.7 highalloc-3.7 rc4-clean rc4-patch Pass 1 55.00 ( 0.00%) 62.00 ( 7.00%) Pass 2 54.00 ( 0.00%) 62.00 ( 8.00%) while Rested 75.00 ( 0.00%) 80.00 ( 5.00%) MMTests Statistics: duration 3.7 3.7 rc4-clean rc4-patch User 1207.59 1207.46 System 1300.55 1299.61 Elapsed 2273.72 2157.06 MMTests Statistics: vmstat 3.7 3.7 rc4-clean rc4-patch Page Ins 3581516 2374368 Page Outs 11148692 10410332 Swap Ins 80 47 Swap Outs 3641 476 Direct pages scanned 37978 33826 Kswapd pages scanned 1828245 1342869 Kswapd pages reclaimed 1710236 1304099 Direct pages reclaimed 32207 31005 Kswapd efficiency 93% 97% Kswapd velocity 804.077 622.546 Direct efficiency 84% 91% Direct velocity 16.703 15.682 Percentage direct scans 2% 2% Page writes by reclaim 79252 9704 Page writes file 75611 9228 Page writes anon 3641 476 Page reclaim immediate 16764 11014 Page rescued immediate 0 0 Slabs scanned 2171904 2152448 Direct inode steals 385 2261 Kswapd inode steals 659137 609670 Kswapd skipped wait 1 69 THP fault alloc 546 631 THP collapse alloc 361 339 THP splits 259 263 THP fault fallback 98 50 THP collapse fail 20 17 Compaction stalls 747 499 Compaction success 244 145 Compaction failures 503 354 Compaction pages moved 370888 474837 Compaction move failure 77378 65259 ===END stress-highalloc This patch: Introduce MIGRATEPAGE_SUCCESS as the default return code for address_space_operations.migratepage() method and documents the expected return code for the same method in failure cases. Signed-off-by: Rafael Aquini Cc: Rusty Russell Cc: "Michael S. Tsirkin" Cc: Rik van Riel Cc: Mel Gorman Cc: Andi Kleen Cc: Konrad Rzeszutek Wilk Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/hugetlbfs/inode.c') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 47e6e2f21e2..4a55f35a6ce 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -582,11 +582,11 @@ static int hugetlbfs_migrate_page(struct address_space *mapping, int rc; rc = migrate_huge_page_move_mapping(mapping, newpage, page); - if (rc) + if (rc != MIGRATEPAGE_SUCCESS) return rc; migrate_page_copy(newpage, page); - return 0; + return MIGRATEPAGE_SUCCESS; } static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf) -- cgit v1.2.3-18-g5258