[PATCH v3 5/6] mm: Support address range reclaim
This patch adds address range reclaim of a process.
The requirement is following as,
Like webkit1, it uses a address space for handling multi tabs.
IOW, it uses *one* process model so all tabs shares address space
of the process. In such scenario, per-process reclaim is rather
coarse-grained so this patch supports more fine-grained reclaim
for being able to reclaim target address range of the process.
For reclaim target range, you should use following format.
echo [addr] [size-byte] > /proc/pid/reclaim
The addr should be page-aligned.
So now reclaim konb's interface is following as.
echo file > /proc/pid/reclaim
reclaim file-backed pages only
echo anon > /proc/pid/reclaim
reclaim anonymous pages only
echo all > /proc/pid/reclaim
reclaim all pages
echo 0x10 8K > /proc/pid/reclaim
reclaim pages in (0x10 - 0x102000)
Signed-off-by: Minchan Kim
---
fs/proc/task_mmu.c | 85 --
1 file changed, 70 insertions(+), 15 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 79b674e..9835028 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -12,6 +12,7 @@
#include
#include
#include
+#include
#include
#include
@@ -1239,11 +1240,14 @@ static ssize_t reclaim_write(struct file *file, const
char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task;
- char buffer[PROC_NUMBUF];
+ char buffer[200];
struct mm_struct *mm;
struct vm_area_struct *vma;
enum reclaim_type type;
char *type_buf;
+ struct mm_walk reclaim_walk = {};
+ unsigned long start = 0;
+ unsigned long end = 0;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
@@ -1259,42 +1263,93 @@ static ssize_t reclaim_write(struct file *file, const
char __user *buf,
type = RECLAIM_ANON;
else if (!strcmp(type_buf, "all"))
type = RECLAIM_ALL;
+ else if (isdigit(*type_buf))
+ type = RECLAIM_RANGE;
else
- return -EINVAL;
+ goto out_err;
+
+ if (type == RECLAIM_RANGE) {
+ char *token;
+ unsigned long long len, len_in, tmp;
+ token = strsep(_buf, " ");
+ if (!token)
+ goto out_err;
+ tmp = memparse(token, );
+ if (tmp & ~PAGE_MASK || tmp > ULONG_MAX)
+ goto out_err;
+ start = tmp;
+
+ token = strsep(_buf, " ");
+ if (!token)
+ goto out_err;
+ len_in = memparse(token, );
+ len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+ if (len > ULONG_MAX)
+ goto out_err;
+ /*
+* Check to see whether len was rounded up from small -ve
+* to zero.
+*/
+ if (len_in && !len)
+ goto out_err;
+
+ end = start + len;
+ if (end < start)
+ goto out_err;
+ }
task = get_proc_task(file->f_path.dentry->d_inode);
if (!task)
return -ESRCH;
mm = get_task_mm(task);
- if (mm) {
- struct mm_walk reclaim_walk = {
- .pmd_entry = reclaim_pte_range,
- .mm = mm,
- };
+ if (!mm)
+ goto out;
- down_read(>mmap_sem);
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- reclaim_walk.private = vma;
+ reclaim_walk.mm = mm;
+ reclaim_walk.pmd_entry = reclaim_pte_range;
+ down_read(>mmap_sem);
+ if (type == RECLAIM_RANGE) {
+ vma = find_vma(mm, start);
+ while (vma) {
+ if (vma->vm_start > end)
+ break;
+ if (is_vm_hugetlb_page(vma))
+ continue;
+
+ reclaim_walk.private = vma;
+ walk_page_range(max(vma->vm_start, start),
+ min(vma->vm_end, end),
+ _walk);
+ vma = vma->vm_next;
+ }
+ } else {
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (is_vm_hugetlb_page(vma))
continue;
if (type == RECLAIM_ANON && vma->vm_file)
continue;
+
if (type == RECLAIM_FILE && !vma->vm_file)
continue;
+ reclaim_walk.private = vma;
walk_page_range(vma->vm_start, vma->vm_end,
- _walk);
[PATCH v3 5/6] mm: Support address range reclaim
This patch adds address range reclaim of a process.
The requirement is following as,
Like webkit1, it uses a address space for handling multi tabs.
IOW, it uses *one* process model so all tabs shares address space
of the process. In such scenario, per-process reclaim is rather
coarse-grained so this patch supports more fine-grained reclaim
for being able to reclaim target address range of the process.
For reclaim target range, you should use following format.
echo [addr] [size-byte] /proc/pid/reclaim
The addr should be page-aligned.
So now reclaim konb's interface is following as.
echo file /proc/pid/reclaim
reclaim file-backed pages only
echo anon /proc/pid/reclaim
reclaim anonymous pages only
echo all /proc/pid/reclaim
reclaim all pages
echo 0x10 8K /proc/pid/reclaim
reclaim pages in (0x10 - 0x102000)
Signed-off-by: Minchan Kim minc...@kernel.org
---
fs/proc/task_mmu.c | 85 --
1 file changed, 70 insertions(+), 15 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 79b674e..9835028 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -12,6 +12,7 @@
#include linux/swap.h
#include linux/swapops.h
#include linux/mm_inline.h
+#include linux/ctype.h
#include asm/elf.h
#include asm/uaccess.h
@@ -1239,11 +1240,14 @@ static ssize_t reclaim_write(struct file *file, const
char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task;
- char buffer[PROC_NUMBUF];
+ char buffer[200];
struct mm_struct *mm;
struct vm_area_struct *vma;
enum reclaim_type type;
char *type_buf;
+ struct mm_walk reclaim_walk = {};
+ unsigned long start = 0;
+ unsigned long end = 0;
memset(buffer, 0, sizeof(buffer));
if (count sizeof(buffer) - 1)
@@ -1259,42 +1263,93 @@ static ssize_t reclaim_write(struct file *file, const
char __user *buf,
type = RECLAIM_ANON;
else if (!strcmp(type_buf, all))
type = RECLAIM_ALL;
+ else if (isdigit(*type_buf))
+ type = RECLAIM_RANGE;
else
- return -EINVAL;
+ goto out_err;
+
+ if (type == RECLAIM_RANGE) {
+ char *token;
+ unsigned long long len, len_in, tmp;
+ token = strsep(type_buf, );
+ if (!token)
+ goto out_err;
+ tmp = memparse(token, token);
+ if (tmp ~PAGE_MASK || tmp ULONG_MAX)
+ goto out_err;
+ start = tmp;
+
+ token = strsep(type_buf, );
+ if (!token)
+ goto out_err;
+ len_in = memparse(token, token);
+ len = (len_in + ~PAGE_MASK) PAGE_MASK;
+ if (len ULONG_MAX)
+ goto out_err;
+ /*
+* Check to see whether len was rounded up from small -ve
+* to zero.
+*/
+ if (len_in !len)
+ goto out_err;
+
+ end = start + len;
+ if (end start)
+ goto out_err;
+ }
task = get_proc_task(file-f_path.dentry-d_inode);
if (!task)
return -ESRCH;
mm = get_task_mm(task);
- if (mm) {
- struct mm_walk reclaim_walk = {
- .pmd_entry = reclaim_pte_range,
- .mm = mm,
- };
+ if (!mm)
+ goto out;
- down_read(mm-mmap_sem);
- for (vma = mm-mmap; vma; vma = vma-vm_next) {
- reclaim_walk.private = vma;
+ reclaim_walk.mm = mm;
+ reclaim_walk.pmd_entry = reclaim_pte_range;
+ down_read(mm-mmap_sem);
+ if (type == RECLAIM_RANGE) {
+ vma = find_vma(mm, start);
+ while (vma) {
+ if (vma-vm_start end)
+ break;
+ if (is_vm_hugetlb_page(vma))
+ continue;
+
+ reclaim_walk.private = vma;
+ walk_page_range(max(vma-vm_start, start),
+ min(vma-vm_end, end),
+ reclaim_walk);
+ vma = vma-vm_next;
+ }
+ } else {
+ for (vma = mm-mmap; vma; vma = vma-vm_next) {
if (is_vm_hugetlb_page(vma))
continue;
if (type == RECLAIM_ANON vma-vm_file)
continue;
+
if (type == RECLAIM_FILE !vma-vm_file)
continue;
+ reclaim_walk.private = vma;
