Eric Lee / smarc-fsl-linux-kernel

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mm/gup_benchmark.c 2.06 KB
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64c349f4a   Kirill A. Shutemov   mm: add infrastru... 
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  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/uaccess.h>
  #include <linux/ktime.h>
  #include <linux/debugfs.h>
  
  #define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_benchmark)
  
  struct gup_benchmark {
  	__u64 delta_usec;
  	__u64 addr;
  	__u64 size;
  	__u32 nr_pages_per_call;
  	__u32 flags;
  };
  
  static int __gup_benchmark_ioctl(unsigned int cmd,
  		struct gup_benchmark *gup)
  {
  	ktime_t start_time, end_time;
518968645   YueHaibing   mm/gup_benchmark:... 
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  	unsigned long i, nr_pages, addr, next;
  	int nr;
64c349f4a   Kirill A. Shutemov   mm: add infrastru... 
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  	struct page **pages;
  
  	nr_pages = gup->size / PAGE_SIZE;
778e1cdd8   Kees Cook   treewide: kvzallo... 
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  	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
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  	if (!pages)
  		return -ENOMEM;
  
  	i = 0;
  	nr = gup->nr_pages_per_call;
  	start_time = ktime_get();
  	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
  		if (nr != gup->nr_pages_per_call)
  			break;
  
  		next = addr + nr * PAGE_SIZE;
  		if (next > gup->addr + gup->size) {
  			next = gup->addr + gup->size;
  			nr = (next - addr) / PAGE_SIZE;
  		}
  
  		nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i);
09e35a4a1   Michael S. Tsirkin   mm/gup_benchmark:... 
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  		if (nr <= 0)
  			break;
64c349f4a   Kirill A. Shutemov   mm: add infrastru... 
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  		i += nr;
  	}
  	end_time = ktime_get();
  
  	gup->delta_usec = ktime_us_delta(end_time, start_time);
  	gup->size = addr - gup->addr;
  
  	for (i = 0; i < nr_pages; i++) {
  		if (!pages[i])
  			break;
  		put_page(pages[i]);
  	}
  
  	kvfree(pages);
  	return 0;
  }
  
  static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
  		unsigned long arg)
  {
  	struct gup_benchmark gup;
  	int ret;
  
  	if (cmd != GUP_FAST_BENCHMARK)
  		return -EINVAL;
  
  	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
  		return -EFAULT;
  
  	ret = __gup_benchmark_ioctl(cmd, &gup);
  	if (ret)
  		return ret;
  
  	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
  		return -EFAULT;
  
  	return 0;
  }
  
  static const struct file_operations gup_benchmark_fops = {
  	.open = nonseekable_open,
  	.unlocked_ioctl = gup_benchmark_ioctl,
  };
  
  static int gup_benchmark_init(void)
  {
  	void *ret;
  
  	ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
  			&gup_benchmark_fops);
  	if (!ret)
  		pr_warn("Failed to create gup_benchmark in debugfs");
  
  	return 0;
  }
  
  late_initcall(gup_benchmark_init);