From: rulinhuang rulin.huang@intel.com
mainline inclusion from mainline-v6.10-rc1 commit aaab830ad887629156ef17097c2ad24ce6fb8177 category: performance bugzilla: https://gitee.com/openeuler/kernel/issues/IAI0KD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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When allocating a new memory area where the mapping address range is known, it is observed that the vmap_node->busy.lock is acquired twice.
The first acquisition occurs in the alloc_vmap_area() function when inserting the vm area into the vm mapping red-black tree. The second acquisition occurs in the setup_vmalloc_vm() function when updating the properties of the vm, such as flags and address, etc.
Combine these two operations together in alloc_vmap_area(), which improves scalability when the vmap_node->busy.lock is contended. By doing so, the need to acquire the lock twice can also be eliminated to once.
With the above change, tested on intel sapphire rapids platform(224 vcpu), a 4% performance improvement is gained on stress-ng/pthread(https://github.com/ColinIanKing/stress-ng), which is the stress test of thread creations.
Link: https://lkml.kernel.org/r/20240307021440.64967-1-rulin.huang@intel.com Co-developed-by: "Chen, Tim C" tim.c.chen@intel.com Signed-off-by: "Chen, Tim C" tim.c.chen@intel.com Co-developed-by: "King, Colin" colin.king@intel.com Signed-off-by: "King, Colin" colin.king@intel.com Signed-off-by: rulinhuang rulin.huang@intel.com Reviewed-by: Baoquan He bhe@redhat.com Reviewed-by: Uladzislau Rezki (Sony) urezki@gmail.com Cc: Tim Chen tim.c.chen@linux.intel.com Cc: Christoph Hellwig hch@infradead.org Cc: Lorenzo Stoakes lstoakes@gmail.com Cc: Wangyang Guo wangyang.guo@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: ZhangPeng zhangpeng362@huawei.com --- mm/vmalloc.c | 50 ++++++++++++++++++++++---------------------------- 1 file changed, 22 insertions(+), 28 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 099ba16f81dc..5a2cdcfaa9fb 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1913,15 +1913,26 @@ node_alloc(unsigned long size, unsigned long align, return va; }
+static inline void setup_vmalloc_vm(struct vm_struct *vm, + struct vmap_area *va, unsigned long flags, const void *caller) +{ + vm->flags = flags; + vm->addr = (void *)va->va_start; + vm->size = va->va_end - va->va_start; + vm->caller = caller; + va->vm = vm; +} + /* * Allocate a region of KVA of the specified size and alignment, within the - * vstart and vend. + * vstart and vend. If vm is passed in, the two will also be bound. */ static struct vmap_area *alloc_vmap_area(unsigned long size, unsigned long align, unsigned long vstart, unsigned long vend, int node, gfp_t gfp_mask, - unsigned long va_flags) + unsigned long va_flags, struct vm_struct *vm, + unsigned long flags, const void *caller) { struct vmap_node *vn; struct vmap_area *va; @@ -1984,6 +1995,9 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, va->vm = NULL; va->flags = (va_flags | vn_id);
+ if (vm) + setup_vmalloc_vm(vm, va, flags, caller); + vn = addr_to_node(va->va_start);
spin_lock(&vn->busy.lock); @@ -2570,7 +2584,8 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, VMALLOC_START, VMALLOC_END, node, gfp_mask, - VMAP_RAM|VMAP_BLOCK); + VMAP_RAM|VMAP_BLOCK, NULL, + 0, NULL); if (IS_ERR(va)) { kfree(vb); return ERR_CAST(va); @@ -2935,7 +2950,8 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) struct vmap_area *va; va = alloc_vmap_area(size, PAGE_SIZE, VMALLOC_START, VMALLOC_END, - node, GFP_KERNEL, VMAP_RAM); + node, GFP_KERNEL, VMAP_RAM, + NULL, 0, NULL); if (IS_ERR(va)) return NULL;
@@ -3038,26 +3054,6 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align) kasan_populate_early_vm_area_shadow(vm->addr, vm->size); }
-static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, - struct vmap_area *va, unsigned long flags, const void *caller) -{ - vm->flags = flags; - vm->addr = (void *)va->va_start; - vm->size = va->va_end - va->va_start; - vm->caller = caller; - va->vm = vm; -} - -static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, - unsigned long flags, const void *caller) -{ - struct vmap_node *vn = addr_to_node(va->va_start); - - spin_lock(&vn->busy.lock); - setup_vmalloc_vm_locked(vm, va, flags, caller); - spin_unlock(&vn->busy.lock); -} - static void clear_vm_uninitialized_flag(struct vm_struct *vm) { /* @@ -3094,14 +3090,12 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, if (!(flags & VM_NO_GUARD)) size += PAGE_SIZE;
- va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0); + va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0, area, flags, caller); if (IS_ERR(va)) { kfree(area); return NULL; }
- setup_vmalloc_vm(area, va, flags, caller); - /* * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a * best-effort approach, as they can be mapped outside of vmalloc code. @@ -4680,7 +4674,7 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
spin_lock(&vn->busy.lock); insert_vmap_area(vas[area], &vn->busy.root, &vn->busy.head); - setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, + setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC, pcpu_get_vm_areas); spin_unlock(&vn->busy.lock); }