cregit-Linux how code gets into the kernel

Release 4.15 mm/gup_benchmark.c

Directory: mm
#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; unsigned long i, nr, nr_pages, addr, next; struct page **pages; nr_pages = gup->size / PAGE_SIZE; pages = kvmalloc(sizeof(void *) * nr_pages, GFP_KERNEL); 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); 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; }

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Kirill A. Shutemov249100.00%1100.00%
Total249100.00%1100.00%


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; }

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Kirill A. Shutemov104100.00%1100.00%
Total104100.00%1100.00%

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; }

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Kirill A. Shutemov41100.00%1100.00%
Total41100.00%1100.00%

late_initcall(gup_benchmark_init);

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PersonTokensPropCommitsCommitProp
Kirill A. Shutemov459100.00%1100.00%
Total459100.00%1100.00%
Directory: mm
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