The quilt patch titled Subject: mm: switch mm->get_unmapped_area() to a flag has been removed from the -mm tree. Its filename was mm-switch-mm-get_unmapped_area-to-a-flag.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> Subject: mm: switch mm->get_unmapped_area() to a flag Date: Mon, 25 Mar 2024 19:16:44 -0700 The mm_struct contains a function pointer *get_unmapped_area(), which is set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown() during the initialization of the mm. Since the function pointer only ever points to two functions that are named the same across all arch's, a function pointer is not really required. In addition future changes will want to add versions of the functions that take additional arguments. So to save a pointers worth of bytes in mm_struct, and prevent adding additional function pointers to mm_struct in future changes, remove it and keep the information about which get_unmapped_area() to use in a flag. Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by mmf_init_flags(). Most MM flags get clobbered on fork. In the pre-existing behavior mm->get_unmapped_area() would get copied to the new mm in dup_mm(), so not clobbering the flag preserves the existing behavior around inheriting the topdown-ness. Introduce a helper, mm_get_unmapped_area(), to easily convert code that refers to the old function pointer to instead select and call either arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the flag. Then drop the mm->get_unmapped_area() function pointer. Leave the get_unmapped_area() pointer in struct file_operations alone. The main purpose of this change is to reorganize in preparation for future changes, but it also converts the calls of mm->get_unmapped_area() from indirect branches into a direct ones. The stress-ng bigheap benchmark calls realloc a lot, which calls through get_unmapped_area() in the kernel. On x86, the change yielded a ~1% improvement there on a retpoline config. In testing a few x86 configs, removing the pointer unfortunately didn't result in any actual size reductions in the compiled layout of mm_struct. But depending on compiler or arch alignment requirements, the change could shrink the size of mm_struct. Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@xxxxxxxxx Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Acked-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxx> Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Deepak Gupta <debug@xxxxxxxxxxxx> Cc: Guo Ren <guoren@xxxxxxxxxx> Cc: Helge Deller <deller@xxxxxx> Cc: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/s390/mm/hugetlbpage.c | 2 +- arch/s390/mm/mmap.c | 4 ++-- arch/sparc/kernel/sys_sparc_64.c | 15 ++++++--------- arch/sparc/mm/hugetlbpage.c | 2 +- arch/x86/kernel/cpu/sgx/driver.c | 2 +- arch/x86/mm/hugetlbpage.c | 2 +- arch/x86/mm/mmap.c | 4 ++-- drivers/char/mem.c | 2 +- drivers/dax/device.c | 6 +++--- fs/hugetlbfs/inode.c | 4 ++-- fs/proc/inode.c | 3 ++- fs/ramfs/file-mmu.c | 2 +- include/linux/mm_types.h | 6 +----- include/linux/sched/coredump.h | 5 ++++- include/linux/sched/mm.h | 5 +++++ io_uring/io_uring.c | 2 +- kernel/bpf/arena.c | 2 +- kernel/bpf/syscall.c | 2 +- mm/debug.c | 6 ------ mm/huge_memory.c | 9 ++++----- mm/mmap.c | 21 ++++++++++++++++++--- mm/shmem.c | 11 +++++------ mm/util.c | 6 +++--- 23 files changed, 66 insertions(+), 57 deletions(-) --- a/arch/s390/mm/hugetlbpage.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/s390/mm/hugetlbpage.c @@ -318,7 +318,7 @@ unsigned long hugetlb_get_unmapped_area( goto check_asce_limit; } - if (mm->get_unmapped_area == arch_get_unmapped_area) + if (!test_bit(MMF_TOPDOWN, &mm->flags)) addr = hugetlb_get_unmapped_area_bottomup(file, addr, len, pgoff, flags); else --- a/arch/s390/mm/mmap.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/s390/mm/mmap.c @@ -185,10 +185,10 @@ void arch_pick_mmap_layout(struct mm_str */ if (mmap_is_legacy(rlim_stack)) { mm->mmap_base = mmap_base_legacy(random_factor); - mm->get_unmapped_area = arch_get_unmapped_area; + clear_bit(MMF_TOPDOWN, &mm->flags); } else { mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; + set_bit(MMF_TOPDOWN, &mm->flags); } } --- a/arch/sparc/kernel/sys_sparc_64.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/sparc/kernel/sys_sparc_64.c @@ -218,14 +218,10 @@ arch_get_unmapped_area_topdown(struct fi unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags) { unsigned long align_goal, addr = -ENOMEM; - unsigned long (*get_area)(struct file *, unsigned long, - unsigned long, unsigned long, unsigned long); - - get_area = current->mm->get_unmapped_area; if (flags & MAP_FIXED) { /* Ok, don't mess with it. */ - return get_area(NULL, orig_addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags); } flags &= ~MAP_SHARED; @@ -238,7 +234,8 @@ unsigned long get_fb_unmapped_area(struc align_goal = (64UL * 1024); do { - addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags); + addr = mm_get_unmapped_area(current->mm, NULL, orig_addr, + len + (align_goal - PAGE_SIZE), pgoff, flags); if (!(addr & ~PAGE_MASK)) { addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL); break; @@ -256,7 +253,7 @@ unsigned long get_fb_unmapped_area(struc * be obtained. */ if (addr & ~PAGE_MASK) - addr = get_area(NULL, orig_addr, len, pgoff, flags); + addr = mm_get_unmapped_area(current->mm, NULL, orig_addr, len, pgoff, flags); return addr; } @@ -292,7 +289,7 @@ void arch_pick_mmap_layout(struct mm_str gap == RLIM_INFINITY || sysctl_legacy_va_layout) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; + clear_bit(MMF_TOPDOWN, &mm->flags); } else { /* We know it's 32-bit */ unsigned long task_size = STACK_TOP32; @@ -303,7 +300,7 @@ void arch_pick_mmap_layout(struct mm_str gap = (task_size / 6 * 5); mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; + set_bit(MMF_TOPDOWN, &mm->flags); } } --- a/arch/sparc/mm/hugetlbpage.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/sparc/mm/hugetlbpage.c @@ -123,7 +123,7 @@ hugetlb_get_unmapped_area(struct file *f (!vma || addr + len <= vm_start_gap(vma))) return addr; } - if (mm->get_unmapped_area == arch_get_unmapped_area) + if (!test_bit(MMF_TOPDOWN, &mm->flags)) return hugetlb_get_unmapped_area_bottomup(file, addr, len, pgoff, flags); else --- a/arch/x86/kernel/cpu/sgx/driver.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/x86/kernel/cpu/sgx/driver.c @@ -113,7 +113,7 @@ static unsigned long sgx_get_unmapped_ar if (flags & MAP_FIXED) return addr; - return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); } #ifdef CONFIG_COMPAT --- a/arch/x86/mm/hugetlbpage.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/x86/mm/hugetlbpage.c @@ -115,7 +115,7 @@ hugetlb_get_unmapped_area(struct file *f } get_unmapped_area: - if (mm->get_unmapped_area == arch_get_unmapped_area) + if (!test_bit(MMF_TOPDOWN, &mm->flags)) return hugetlb_get_unmapped_area_bottomup(file, addr, len, pgoff, flags); else --- a/arch/x86/mm/mmap.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/arch/x86/mm/mmap.c @@ -129,9 +129,9 @@ static void arch_pick_mmap_base(unsigned void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { if (mmap_is_legacy()) - mm->get_unmapped_area = arch_get_unmapped_area; + clear_bit(MMF_TOPDOWN, &mm->flags); else - mm->get_unmapped_area = arch_get_unmapped_area_topdown; + set_bit(MMF_TOPDOWN, &mm->flags); arch_pick_mmap_base(&mm->mmap_base, &mm->mmap_legacy_base, arch_rnd(mmap64_rnd_bits), task_size_64bit(0), --- a/drivers/char/mem.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/drivers/char/mem.c @@ -544,7 +544,7 @@ static unsigned long get_unmapped_area_z } /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ - return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); #else return -ENOSYS; #endif --- a/drivers/dax/device.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/drivers/dax/device.c @@ -329,14 +329,14 @@ static unsigned long dax_get_unmapped_ar if ((off + len_align) < off) goto out; - addr_align = current->mm->get_unmapped_area(filp, addr, len_align, - pgoff, flags); + addr_align = mm_get_unmapped_area(current->mm, filp, addr, len_align, + pgoff, flags); if (!IS_ERR_VALUE(addr_align)) { addr_align += (off - addr_align) & (align - 1); return addr_align; } out: - return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); } static const struct address_space_operations dev_dax_aops = { --- a/fs/hugetlbfs/inode.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/fs/hugetlbfs/inode.c @@ -249,11 +249,11 @@ generic_hugetlb_get_unmapped_area(struct } /* - * Use mm->get_unmapped_area value as a hint to use topdown routine. + * Use MMF_TOPDOWN flag as a hint to use topdown routine. * If architectures have special needs, they should define their own * version of hugetlb_get_unmapped_area. */ - if (mm->get_unmapped_area == arch_get_unmapped_area_topdown) + if (test_bit(MMF_TOPDOWN, &mm->flags)) return hugetlb_get_unmapped_area_topdown(file, addr, len, pgoff, flags); return hugetlb_get_unmapped_area_bottomup(file, addr, len, --- a/fs/proc/inode.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/fs/proc/inode.c @@ -455,8 +455,9 @@ pde_get_unmapped_area(struct proc_dir_en return pde->proc_ops->proc_get_unmapped_area(file, orig_addr, len, pgoff, flags); #ifdef CONFIG_MMU - return current->mm->get_unmapped_area(file, orig_addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, file, orig_addr, len, pgoff, flags); #endif + return orig_addr; } --- a/fs/ramfs/file-mmu.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/fs/ramfs/file-mmu.c @@ -35,7 +35,7 @@ static unsigned long ramfs_mmu_get_unmap unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { - return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); } const struct file_operations ramfs_file_operations = { --- a/include/linux/mm_types.h~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/include/linux/mm_types.h @@ -777,11 +777,7 @@ struct mm_struct { } ____cacheline_aligned_in_smp; struct maple_tree mm_mt; -#ifdef CONFIG_MMU - unsigned long (*get_unmapped_area) (struct file *filp, - unsigned long addr, unsigned long len, - unsigned long pgoff, unsigned long flags); -#endif + unsigned long mmap_base; /* base of mmap area */ unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES --- a/include/linux/sched/coredump.h~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/include/linux/sched/coredump.h @@ -92,9 +92,12 @@ static inline int get_dumpable(struct mm #define MMF_VM_MERGE_ANY 30 #define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) +#define MMF_TOPDOWN 31 /* mm searches top down by default */ +#define MMF_TOPDOWN_MASK (1 << MMF_TOPDOWN) + #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ - MMF_VM_MERGE_ANY_MASK) + MMF_VM_MERGE_ANY_MASK | MMF_TOPDOWN_MASK) static inline unsigned long mmf_init_flags(unsigned long flags) { --- a/include/linux/sched/mm.h~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/include/linux/sched/mm.h @@ -8,6 +8,7 @@ #include <linux/mm_types.h> #include <linux/gfp.h> #include <linux/sync_core.h> +#include <linux/sched/coredump.h> /* * Routines for handling mm_structs @@ -186,6 +187,10 @@ arch_get_unmapped_area_topdown(struct fi unsigned long len, unsigned long pgoff, unsigned long flags); +unsigned long mm_get_unmapped_area(struct mm_struct *mm, struct file *filp, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags); + unsigned long generic_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, --- a/io_uring/io_uring.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/io_uring/io_uring.c @@ -3525,7 +3525,7 @@ static unsigned long io_uring_mmu_get_un #else addr = 0UL; #endif - return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); } #else /* !CONFIG_MMU */ --- a/kernel/bpf/arena.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/kernel/bpf/arena.c @@ -314,7 +314,7 @@ static unsigned long arena_get_unmapped_ return -EINVAL; } - ret = current->mm->get_unmapped_area(filp, addr, len * 2, 0, flags); + ret = mm_get_unmapped_area(current->mm, filp, addr, len * 2, 0, flags); if (IS_ERR_VALUE(ret)) return ret; if ((ret >> 32) == ((ret + len - 1) >> 32)) --- a/kernel/bpf/syscall.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/kernel/bpf/syscall.c @@ -980,7 +980,7 @@ static unsigned long bpf_get_unmapped_ar if (map->ops->map_get_unmapped_area) return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); #ifdef CONFIG_MMU - return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); #else return addr; #endif --- a/mm/debug.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/mm/debug.c @@ -177,9 +177,6 @@ EXPORT_SYMBOL(dump_vma); void dump_mm(const struct mm_struct *mm) { pr_emerg("mm %px task_size %lu\n" -#ifdef CONFIG_MMU - "get_unmapped_area %px\n" -#endif "mmap_base %lu mmap_legacy_base %lu\n" "pgd %px mm_users %d mm_count %d pgtables_bytes %lu map_count %d\n" "hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n" @@ -205,9 +202,6 @@ void dump_mm(const struct mm_struct *mm) "def_flags: %#lx(%pGv)\n", mm, mm->task_size, -#ifdef CONFIG_MMU - mm->get_unmapped_area, -#endif mm->mmap_base, mm->mmap_legacy_base, mm->pgd, atomic_read(&mm->mm_users), atomic_read(&mm->mm_count), --- a/mm/huge_memory.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/mm/huge_memory.c @@ -816,8 +816,8 @@ static unsigned long __thp_get_unmapped_ if (len_pad < len || (off + len_pad) < off) return 0; - ret = current->mm->get_unmapped_area(filp, addr, len_pad, - off >> PAGE_SHIFT, flags); + ret = mm_get_unmapped_area(current->mm, filp, addr, len_pad, + off >> PAGE_SHIFT, flags); /* * The failure might be due to length padding. The caller will retry @@ -835,8 +835,7 @@ static unsigned long __thp_get_unmapped_ off_sub = (off - ret) & (size - 1); - if (current->mm->get_unmapped_area == arch_get_unmapped_area_topdown && - !off_sub) + if (test_bit(MMF_TOPDOWN, ¤t->mm->flags) && !off_sub) return ret + size; ret += off_sub; @@ -853,7 +852,7 @@ unsigned long thp_get_unmapped_area(stru if (ret) return ret; - return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); } EXPORT_SYMBOL_GPL(thp_get_unmapped_area); --- a/mm/mmap.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/mm/mmap.c @@ -1812,7 +1812,8 @@ get_unmapped_area(struct file *file, uns unsigned long pgoff, unsigned long flags) { unsigned long (*get_area)(struct file *, unsigned long, - unsigned long, unsigned long, unsigned long); + unsigned long, unsigned long, unsigned long) + = NULL; unsigned long error = arch_mmap_check(addr, len, flags); if (error) @@ -1822,7 +1823,6 @@ get_unmapped_area(struct file *file, uns if (len > TASK_SIZE) return -ENOMEM; - get_area = current->mm->get_unmapped_area; if (file) { if (file->f_op->get_unmapped_area) get_area = file->f_op->get_unmapped_area; @@ -1841,7 +1841,11 @@ get_unmapped_area(struct file *file, uns if (!file) pgoff = 0; - addr = get_area(file, addr, len, pgoff, flags); + if (get_area) + addr = get_area(file, addr, len, pgoff, flags); + else + addr = mm_get_unmapped_area(current->mm, file, addr, len, + pgoff, flags); if (IS_ERR_VALUE(addr)) return addr; @@ -1856,6 +1860,17 @@ get_unmapped_area(struct file *file, uns EXPORT_SYMBOL(get_unmapped_area); +unsigned long +mm_get_unmapped_area(struct mm_struct *mm, struct file *file, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + if (test_bit(MMF_TOPDOWN, &mm->flags)) + return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags); + return arch_get_unmapped_area(file, addr, len, pgoff, flags); +} +EXPORT_SYMBOL(mm_get_unmapped_area); + /** * find_vma_intersection() - Look up the first VMA which intersects the interval * @mm: The process address space. --- a/mm/shmem.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/mm/shmem.c @@ -2267,8 +2267,6 @@ unsigned long shmem_get_unmapped_area(st unsigned long uaddr, unsigned long len, unsigned long pgoff, unsigned long flags) { - unsigned long (*get_area)(struct file *, - unsigned long, unsigned long, unsigned long, unsigned long); unsigned long addr; unsigned long offset; unsigned long inflated_len; @@ -2278,8 +2276,8 @@ unsigned long shmem_get_unmapped_area(st if (len > TASK_SIZE) return -ENOMEM; - get_area = current->mm->get_unmapped_area; - addr = get_area(file, uaddr, len, pgoff, flags); + addr = mm_get_unmapped_area(current->mm, file, uaddr, len, pgoff, + flags); if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) return addr; @@ -2336,7 +2334,8 @@ unsigned long shmem_get_unmapped_area(st if (inflated_len < len) return addr; - inflated_addr = get_area(NULL, uaddr, inflated_len, 0, flags); + inflated_addr = mm_get_unmapped_area(current->mm, NULL, uaddr, + inflated_len, 0, flags); if (IS_ERR_VALUE(inflated_addr)) return addr; if (inflated_addr & ~PAGE_MASK) @@ -4801,7 +4800,7 @@ unsigned long shmem_get_unmapped_area(st unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { - return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); } #endif --- a/mm/util.c~mm-switch-mm-get_unmapped_area-to-a-flag +++ a/mm/util.c @@ -469,17 +469,17 @@ void arch_pick_mmap_layout(struct mm_str if (mmap_is_legacy(rlim_stack)) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; + clear_bit(MMF_TOPDOWN, &mm->flags); } else { mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; + set_bit(MMF_TOPDOWN, &mm->flags); } } #elif defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { mm->mmap_base = TASK_UNMAPPED_BASE; - mm->get_unmapped_area = arch_get_unmapped_area; + clear_bit(MMF_TOPDOWN, &mm->flags); } #endif _ Patches currently in -mm which might be from rick.p.edgecombe@xxxxxxxxx are