/*
* copy one vm_area from one task to the other. Assumes the page tables
* already present in the new task to be cleared in the whole range
* covered by this vma.
*
* 08Jan98 Merged into one routine from several inline routines to reduce
* variable count and make things faster. -jj
*/
int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma)
{
pgd_t * src_pgd, * dst_pgd;
unsigned long address = vma->vm_start;
unsigned long end = vma->vm_end;
unsigned long cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
src_pgd = pgd_offset(src, address)-1;
dst_pgd = pgd_offset(dst, address)-1;
for (;;) {
pmd_t * src_pmd, * dst_pmd;
src_pgd++; dst_pgd++;
/* copy_pmd_range */
if (pgd_none(*src_pgd))
goto skip_copy_pmd_range;
if (pgd_bad(*src_pgd)) {
pgd_ERROR(*src_pgd);
pgd_clear(src_pgd);
skip_copy_pmd_range: address = (address + PGDIR_SIZE) & PGDIR_MASK;
if (!address || (address >= end))
goto out;
continue;
}
if (pgd_none(*dst_pgd)) {
if (!pmd_alloc(dst_pgd, 0))
goto nomem;
}
src_pmd = pmd_offset(src_pgd, address);
dst_pmd = pmd_offset(dst_pgd, address);
do {
pte_t * src_pte, * dst_pte;
/* copy_pte_range */
if (pmd_none(*src_pmd))
goto skip_copy_pte_range;
if (pmd_bad(*src_pmd)) {
pmd_ERROR(*src_pmd);
pmd_clear(src_pmd);
skip_copy_pte_range: address = (address + PMD_SIZE) & PMD_MASK;
if (address >= end)
goto out;
goto cont_copy_pmd_range;
}
if (pmd_none(*dst_pmd)) {
if (!pte_alloc(dst_pmd, 0))
goto nomem;
}
src_pte = pte_offset(src_pmd, address);
dst_pte = pte_offset(dst_pmd, address);
do {
pte_t pte = *src_pte;
struct page *ptepage;
/* copy_one_pte */
if (pte_none(pte))
goto cont_copy_pte_range_noset;
if (!pte_present(pte)) {
swap_duplicate(pte_to_swp_entry(pte));
goto cont_copy_pte_range;
}
ptepage = pte_page(pte);
if ((!VALID_PAGE(ptepage)) ||
PageReserved(ptepage))
goto cont_copy_pte_range;
/* If it's a COW mapping, write protect it both in the parent and the child */
if (cow) {
ptep_set_wrprotect(src_pte);
pte = *src_pte;
}
/* If it's a shared mapping, mark it clean in the child */
if (vma->vm_flags & VM_SHARED)
pte = pte_mkclean(pte);
pte = pte_mkold(pte);
get_page(ptepage);
cont_copy_pte_range: set_pte(dst_pte, pte);
cont_copy_pte_range_noset: address += PAGE_SIZE;
if (address >= end)
goto out;
src_pte++;
dst_pte++;
} while ((unsigned long)src_pte & PTE_TABLE_MASK);
cont_copy_pmd_range: src_pmd++;
dst_pmd++;
} while ((unsigned long)src_pmd & PMD_TABLE_MASK);
}
out:
return 0;
nomem:
return -ENOMEM;
}
/*pgtable sequential scan and count for __access_bits.*/
static int scan_pgtable(void)
{
pgd_t *pgd = NULL;
pud_t *pud = NULL;
pmd_t *pmd = NULL;
pte_t *ptep, pte;
spinlock_t *ptl;
struct mm_struct *mm;
struct vm_area_struct *vma;
unsigned long start = 0; /*the start of address.*/
unsigned long end = 0; /*the end of address.*/
unsigned long address = 0; /* the address of vma.*/
int number_hotpages = 0; /* the number of hot pages */
int number_vpages = 0;
int cycle_index = 0; /* the loop counter, which denotes ITERATIONS. */
/* the array that records the number of hot page in every cycle */
int hot_page[ITERATIONS];
int number_current_pg = 0;
int pg_count = 0;
int j = 0;
int times = 0; /* records reuse time*/
/* some variables that describe page "heat" */
int hig = 0;
int mid = 0;
int low = 0;
int llow = 0;
int lllow = 0;
int llllow = 0;
int all_pages = 0;/* the total number of pages */
/*the average number of hot pages in each iteration.*/
long avg_hotpage=0;
/*the total number of memory accesses across all pages*/
long num_access=0;
/* avg utilization of each page */
int avg_page_utilization = 0;
/*get the handle of current running benchmark.*/
struct task_struct *bench_process = get_current_process();
if(bench_process == NULL)
{
printk("sysmon: get no process handle in scan_pgtable function...exit&trying again...\n");
return 0;
}
else /* get the process*/
mm = bench_process->mm;
if(mm == NULL)
{
printk("sysmon: error mm is NULL, return back & trying...\n");
return 0;
}
for(j = 0; j < PAGE_ALL; j++)
page_heat[j] = -1;
for(j = 0; j < ITERATIONS; j++)
{
hot_page[j] = 0;
reuse_time[j] = 0;
dirty_page[j] = 0;
}
/*yanghao*/
times = 0;
for(cycle_index = 0; cycle_index < ITERATIONS; cycle_index++)
{
number_hotpages = 0;
/*scan each vma*/
for(vma = mm->mmap; vma; vma = vma->vm_next)
{
start = vma->vm_start;
end = vma->vm_end;
mm = vma->vm_mm;
/*in each vma, we check all pages*/
for(address = start; address < end; address += PAGE_SIZE)
{
/*scan page table for each page in this VMA*/
pgd = pgd_offset(mm, address);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
continue;
pud = pud_offset(pgd, address);
if (pud_none(*pud) || unlikely(pud_bad(*pud)))
continue;
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
continue;
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
pte = *ptep;
if(pte_present(pte))
{
if(pte_young(pte)) /*hot page*/
{
/*re-set and clear _access_bits to 0*/
pte = pte_mkold(pte);
set_pte_at(mm, address, ptep, pte);
/*yanghao:re-set and clear _dirty_bits to 0*/
pte = pte_mkclean(pte);
set_pte_at(mm, address, ptep, pte);
}
}
else /*no page pte_none*/
{
pte_unmap_unlock(ptep, ptl);
continue;
}
pte_unmap_unlock(ptep, ptl);
page_counts++;
}
}
/*count the number of hot pages*/
if(bench_process == NULL)
{
printk("sysmon: get no process handle in scan_pgtable function...exit&trying again...\n");
return 0;
}
else /*get the process*/
mm = bench_process->mm;
if(mm == NULL)
{
printk("sysmon: error mm is NULL, return back & trying...\n");
return 0;
}
number_vpages = 0;
sampling_interval = page_counts / 250; /*yanghao:*/
page_counts = 0;
for(vma = mm->mmap; vma; vma = vma->vm_next)
{
start = vma->vm_start;
end = vma->vm_end;
/*scan each page in this VMA*/
mm = vma->vm_mm;
pg_count = 0;
for(address = start; address < end; address += PAGE_SIZE)
{
/*scan page table for each page in this VMA*/
pgd = pgd_offset(mm, address);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
continue;
pud = pud_offset(pgd, address);
if (pud_none(*pud) || unlikely(pud_bad(*pud)))
continue;
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
continue;
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
pte = *ptep;
if(pte_present(pte))
{
if(pte_young(pte)) /* hot pages*/
{
number_current_pg = pg_count + number_vpages;
page_heat[number_current_pg]++;
hot_page[cycle_index]++;
/*yanghao:*/
if (page_counts == random_page)
{
times++;
if (pte_dirty(pte))
dirty_page[cycle_index] = 1;
}
}
else
{
if (page_counts == random_page)
reuse_time[times]++;
}
}
pg_count++;
pte_unmap_unlock(ptep, ptl);
page_counts++;
}
number_vpages += (int)(end - start)/PAGE_SIZE;
}
}
/*yanghao:cal. the No. of random_page*/
random_page += sampling_interval;
if(random_page >= page_counts)
random_page=page_counts / 300;
/*****************************OUTPUT************************************/
for(j = 0; j < PAGE_ALL; j++)
{
if(page_heat[j] < VH && page_heat[j] > H)
hig++;
if(page_heat[j] > M && page_heat[j] <= H)
mid++;
if(page_heat[j] <= M && page_heat[j] > L)
low++;
if(page_heat[j] > VL_MAX && page_heat[j] <= L)
llow++;
if(page_heat[j] > VL_MIN && page_heat[j] <= VL_MAX)
lllow++;
if(page_heat[j] >= 0 && page_heat[j] <= VL_MIN)
llllow++;
if(page_heat[j] > -1)
all_pages++;
}
/*the values reflect the accessing frequency of each physical page.*/
printk("[LOG: after sampling (%d loops) ...] ",ITERATIONS);
printk("the values denote the physical page accessing frequence.\n");
printk("-->hig (150,200) is %d. Indicating the number of re-used pages is high.\n",hig);
printk("-->mid (100,150] is %d.\n",mid);
printk("-->low (64,100] is %d.\n",low);
printk("-->llow (10,64] is %d. In locality,no too many re-used pages.\n",llow);
printk("-->lllow (5,10] is %d.\n",lllow);
printk("-->llllow [1,5] is %d.\n",llllow);
for(j = 0;j < ITERATIONS; j++)
avg_hotpage += hot_page[j];
avg_hotpage /= (j+1);
/*
* new step@20140704
* (1)the different phases of memory utilization
* (2)the avg. page accessing utilization
* (3)memory pages layout and spectrum
*/
for(j = 0; j < PAGE_ALL; j++)
if(page_heat[j] > -1) /*the page that is accessed at least once.*/
num_access += (page_heat[j] + 1);
printk("the total number of memory accesses is %ld, the average is %ld\n",
num_access, num_access / ITERATIONS);
avg_page_utilization = num_access / all_pages;
printk("Avg hot pages num is %ld, all used pages num is %d, avg utilization of each page is %d\n",
avg_hotpage, all_pages, avg_page_utilization);
/*yanghao:print the information about reuse-distance*/
if ((times == 0) && (reuse_time[0] ==0))
printk("the page No.%d is not available.",random_page);
else
{
if ((times == 0) && (reuse_time[0] == 0))
printk("the page No.%d was not used in this 200 loops.",random_page);
else
{
if (times < ITERATIONS)
times++;
printk("the reusetime of page No.%d is:",random_page);
for (j = 0; j < times; j++)
printk("%d ",reuse_time[j]);
printk("\n");
printk("the total number of the digit above denotes the sum that page NO.%d be accessd in %d loops.\n",
random_page,ITERATIONS);
printk("each digit means the sum loops that between current loop and the last loop.\n");
}
}
printk("\n\n");
return 1;
}
