On 05/15/2019 05:21 AM, Roman Gushchin wrote: > __vunmap() calls find_vm_area() twice without an obvious reason: > first directly to get the area pointer, second indirectly by calling > vm_remove_mappings()->remove_vm_area(), which is again searching > for the area. > > To remove this redundancy, let's split remove_vm_area() into > __remove_vm_area(struct vmap_area *), which performs the actual area > removal, and remove_vm_area(const void *addr) wrapper, which can > be used everywhere, where it has been used before. Let's pass > a pointer to the vm_area instead of vm_struct to vm_remove_mappings(), > so it can pass it to __remove_vm_area() and avoid the redundant area > lookup. > > On my test setup, I've got 5-10% speed up on vfree()'ing 1000000 > of 4-pages vmalloc blocks. Though results from 1000000 single page vmalloc blocks remain inconclusive, 4-page based vmalloc block's result shows improvement in the range of 5-10%.
