From fe9041c245196c6c61091ccc2c74b73ab9a5fc50 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 3 Jun 2019 08:55:13 +0200 Subject: vmalloc: lift the arm flag for coherent mappings to common code The arm architecture had a VM_ARM_DMA_CONSISTENT flag to mark DMA coherent remapping for a while. Lift this flag to common code so that we can use it generically. We also check it in the only place VM_USERMAP is directly check so that we can entirely replace that flag as well (although I'm not even sure why we'd want to allow remapping DMA appings, but I'd rather not change behavior). Signed-off-by: Christoph Hellwig --- include/linux/vmalloc.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/vmalloc.h') diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 9b21d0047710..dfa718ffdd4f 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -18,6 +18,7 @@ struct notifier_block; /* in notifier.h */ #define VM_ALLOC 0x00000002 /* vmalloc() */ #define VM_MAP 0x00000004 /* vmap()ed pages */ #define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */ +#define VM_DMA_COHERENT 0x00000010 /* dma_alloc_coherent */ #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ #define VM_NO_GUARD 0x00000040 /* don't add guard page */ #define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ @@ -26,6 +27,7 @@ struct notifier_block; /* in notifier.h */ * vfree_atomic(). */ #define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap */ + /* bits [20..32] reserved for arch specific ioremap internals */ /* -- cgit From 688fcbfc06e4fdfbb7e1d5a942a1460fe6379d2d Mon Sep 17 00:00:00 2001 From: Pengfei Li Date: Mon, 23 Sep 2019 15:36:39 -0700 Subject: mm/vmalloc: modify struct vmap_area to reduce its size Objective --------- The current implementation of struct vmap_area wasted space. After applying this commit, sizeof(struct vmap_area) has been reduced from 11 words to 8 words. Description ----------- 1) Pack "subtree_max_size", "vm" and "purge_list". This is no problem because A) "subtree_max_size" is only used when vmap_area is in "free" tree B) "vm" is only used when vmap_area is in "busy" tree C) "purge_list" is only used when vmap_area is in vmap_purge_list 2) Eliminate "flags". ;Since only one flag VM_VM_AREA is being used, and the same thing can be done by judging whether "vm" is NULL, then the "flags" can be eliminated. Link: http://lkml.kernel.org/r/20190716152656.12255-3-lpf.vector@gmail.com Signed-off-by: Pengfei Li Suggested-by: Uladzislau Rezki (Sony) Reviewed-by: Uladzislau Rezki (Sony) Cc: Hillf Danton Cc: Matthew Wilcox Cc: Michal Hocko Cc: Oleksiy Avramchenko Cc: Roman Gushchin Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vmalloc.h | 20 +++++++++++++------- mm/vmalloc.c | 24 ++++++++++-------------- 2 files changed, 23 insertions(+), 21 deletions(-) (limited to 'include/linux/vmalloc.h') diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index dfa718ffdd4f..4e7809408073 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -53,15 +53,21 @@ struct vmap_area { unsigned long va_start; unsigned long va_end; - /* - * Largest available free size in subtree. - */ - unsigned long subtree_max_size; - unsigned long flags; struct rb_node rb_node; /* address sorted rbtree */ struct list_head list; /* address sorted list */ - struct llist_node purge_list; /* "lazy purge" list */ - struct vm_struct *vm; + + /* + * The following three variables can be packed, because + * a vmap_area object is always one of the three states: + * 1) in "free" tree (root is vmap_area_root) + * 2) in "busy" tree (root is free_vmap_area_root) + * 3) in purge list (head is vmap_purge_list) + */ + union { + unsigned long subtree_max_size; /* in "free" tree */ + struct vm_struct *vm; /* in "busy" tree */ + struct llist_node purge_list; /* in purge list */ + }; }; /* diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d535ef125bda..f095843fc243 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -329,7 +329,6 @@ EXPORT_SYMBOL(vmalloc_to_pfn); #define DEBUG_AUGMENT_PROPAGATE_CHECK 0 #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 -#define VM_VM_AREA 0x04 static DEFINE_SPINLOCK(vmap_area_lock); /* Export for kexec only */ @@ -1115,7 +1114,7 @@ retry: va->va_start = addr; va->va_end = addr + size; - va->flags = 0; + va->vm = NULL; insert_vmap_area(va, &vmap_area_root, &vmap_area_list); spin_unlock(&vmap_area_lock); @@ -1928,7 +1927,6 @@ void __init vmalloc_init(void) if (WARN_ON_ONCE(!va)) continue; - va->flags = VM_VM_AREA; va->va_start = (unsigned long)tmp->addr; va->va_end = va->va_start + tmp->size; va->vm = tmp; @@ -2026,7 +2024,6 @@ static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, vm->size = va->va_end - va->va_start; vm->caller = caller; va->vm = vm; - va->flags |= VM_VM_AREA; spin_unlock(&vmap_area_lock); } @@ -2131,10 +2128,10 @@ struct vm_struct *find_vm_area(const void *addr) struct vmap_area *va; va = find_vmap_area((unsigned long)addr); - if (va && va->flags & VM_VM_AREA) - return va->vm; + if (!va) + return NULL; - return NULL; + return va->vm; } /** @@ -2155,11 +2152,10 @@ struct vm_struct *remove_vm_area(const void *addr) spin_lock(&vmap_area_lock); va = __find_vmap_area((unsigned long)addr); - if (va && va->flags & VM_VM_AREA) { + if (va && va->vm) { struct vm_struct *vm = va->vm; va->vm = NULL; - va->flags &= ~VM_VM_AREA; spin_unlock(&vmap_area_lock); kasan_free_shadow(vm); @@ -2862,7 +2858,7 @@ long vread(char *buf, char *addr, unsigned long count) if (!count) break; - if (!(va->flags & VM_VM_AREA)) + if (!va->vm) continue; vm = va->vm; @@ -2942,7 +2938,7 @@ long vwrite(char *buf, char *addr, unsigned long count) if (!count) break; - if (!(va->flags & VM_VM_AREA)) + if (!va->vm) continue; vm = va->vm; @@ -3485,10 +3481,10 @@ static int s_show(struct seq_file *m, void *p) va = list_entry(p, struct vmap_area, list); /* - * s_show can encounter race with remove_vm_area, !VM_VM_AREA on - * behalf of vmap area is being tear down or vm_map_ram allocation. + * s_show can encounter race with remove_vm_area, !vm on behalf + * of vmap area is being tear down or vm_map_ram allocation. */ - if (!(va->flags & VM_VM_AREA)) { + if (!va->vm) { seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", (void *)va->va_start, (void *)va->va_end, va->va_end - va->va_start); -- cgit