Re: [PATCH OLK-6.6 07/10] etmem: add etmem swap feature

On 2024/1/9 18:58, Yuchen Tang wrote:

euleros inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T1MB?from=project-issue CVE: NA

---

This patch implements the etmem swap feature.

etmem swap, like etmem scan, also communicated with the user space program thought a registered proc file system. It adds target pages to swap cache to be further reclaimed by kswapd, and dwell in swap space.

Signed-off-by: yanxiaodan yanxiaodan@huawei.com Signed-off-by: linmiaohe linmiaohe@huawei.com Signed-off-by: louhongxiang louhongxiang@huawei.com Signed-off-by: liubo liubo254@huawei.com Signed-off-by: geruijun geruijun@huawei.com Signed-off-by: Yuchen Tang tangyuchen5@huawei.com

---

fs/proc/Makefile | 5 +- fs/proc/base.c | 2 + fs/proc/etmem_proc.c | 94 ++++++++++++++++++++++++++++++++++++ fs/proc/etmem_swap.c | 109 ++++++++++++++++++++++++++++++++++++++++++ fs/proc/internal.h | 1 + include/linux/etmem.h | 13 +++++ mm/Kconfig | 10 ++++ mm/Makefile | 1 + mm/etmem.c | 64 +++++++++++++++++++++++++ 9 files changed, 297 insertions(+), 2 deletions(-) create mode 100644 fs/proc/etmem_swap.c create mode 100644 mm/etmem.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile index b9a7bc7d8a75..fe283f354d61 100644 --- a/fs/proc/Makefile +++ b/fs/proc/Makefile @@ -34,5 +34,6 @@ proc-$(CONFIG_PROC_VMCORE) += vmcore.o proc-$(CONFIG_PRINTK) += kmsg.o proc-$(CONFIG_PROC_PAGE_MONITOR) += page.o proc-$(CONFIG_BOOT_CONFIG) += bootconfig.o -obj-$(CONFIG_ETMEM_SCAN) += etmem_scan.o -proc-${CONFIG_ETMEM} += etmem_proc.o +obj-$(CONFIG_ETMEM_SCAN) += etmem_scan.o +obj-$(CONFIG_ETMEM_SWAP) += etmem_swap.o +proc-${CONFIG_ETMEM} += etmem_proc.o

一直没注意这个地方，为啥改，对齐？ 那之前补丁对齐不对吗

diff --git a/fs/proc/base.c b/fs/proc/base.c index eb5ab83e5c22..5be0273a70c4 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3357,6 +3357,7 @@ static const struct pid_entry tgid_base_stuff[] = { #endif #ifdef CONFIG_ETMEM REG("idle_pages", S_IRUSR|S_IWUSR, proc_mm_idle_operations),

• REG("swap_pages", S_IWUSR, proc_mm_swap_operations), #endif #ifdef CONFIG_SECURITY DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),

@@ -3709,6 +3710,7 @@ static const struct pid_entry tid_base_stuff[] = { #endif #ifdef CONFIG_ETMEM REG("idle_pages", S_IRUSR|S_IWUSR, proc_mm_idle_operations),

• REG("swap_pages", S_IWUSR, proc_mm_swap_operations), #endif #ifdef CONFIG_SECURITY DIR("attr", S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),

diff --git a/fs/proc/etmem_proc.c b/fs/proc/etmem_proc.c index edacb9260345..2e6712cc43b2 100644 --- a/fs/proc/etmem_proc.c +++ b/fs/proc/etmem_proc.c @@ -120,3 +120,97 @@ const struct file_operations proc_mm_idle_operations = { .release = mm_idle_release, .unlocked_ioctl = mm_idle_ioctl, };

+static DEFINE_SPINLOCK(swap_lock);

+static int page_swap_lock(struct file *file, int is_lock, struct file_lock *flock) +{

• if (is_lock)

• spin_lock(&swap_lock);
  

• else

• spin_unlock(&swap_lock);
  

• return 0;

+} +/*swap pages*/ +struct file_operations proc_swap_pages_operations = {

• .flock = page_swap_lock,

+}; +EXPORT_SYMBOL_GPL(proc_swap_pages_operations);

+static ssize_t mm_swap_write(struct file *file, const char __user *buf,

• size_t count, loff_t *ppos)
  

+{

• if (proc_swap_pages_operations.write)

• return proc_swap_pages_operations.write(file, buf, count, ppos);
  

• return -1;

+}

+static int mm_swap_open(struct inode *inode, struct file *file) +{

• struct mm_struct *mm = NULL;
• struct module *module = NULL;
• int ret = -1;
• if (!file_ns_capable(file, &init_user_ns, CAP_SYS_ADMIN))

• return -EPERM;
  

• page_swap_lock(NULL, 1, NULL);
• module = proc_swap_pages_operations.owner;
• if (module != NULL && try_module_get(module))

• ret = 0;
  

• page_swap_lock(NULL, 0, NULL);
• if (ret != 0) {

• /* no swap ko installed, avoid to return valid file */
  

• return -ENODEV;
  

• }
• mm = proc_mem_open(inode, PTRACE_MODE_READ);
• if (IS_ERR(mm)) {

• module_put(module);
  

• return PTR_ERR(mm);
  

• }
• file->private_data = mm;
• if (proc_swap_pages_operations.open)

• ret = proc_swap_pages_operations.open(inode, file);
  

• if (ret != 0)

• module_put(module);
  

• return ret;

+}

+static int mm_swap_release(struct inode *inode, struct file *file) +{

• struct mm_struct *mm = file->private_data;
• int ret = 0;
• if (mm)

• mmdrop(mm);
  

• if (proc_swap_pages_operations.release)

• ret = proc_swap_pages_operations.release(inode, file);
  

• if (proc_swap_pages_operations.owner)

• module_put(proc_swap_pages_operations.owner);
  

• return ret;

+}

+static long mm_swap_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{

• if (proc_swap_pages_operations.unlocked_ioctl)

• return proc_swap_pages_operations.unlocked_ioctl(filp, cmd, arg);
  

• return 0;

+}

+const struct file_operations proc_mm_swap_operations = {

• .llseek = mem_lseek,
• .write = mm_swap_write,
• .open = mm_swap_open,
• .release = mm_swap_release,
• .unlocked_ioctl = mm_swap_ioctl,

+}; diff --git a/fs/proc/etmem_swap.c b/fs/proc/etmem_swap.c new file mode 100644 index 000000000000..4aad6b9db9a6 --- /dev/null +++ b/fs/proc/etmem_swap.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/proc_fs.h> +#include <linux/sched/mm.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/mempolicy.h> +#include <linux/uaccess.h> +#include <linux/delay.h> +#include <linux/etmem.h>

+static ssize_t swap_pages_write(struct file *file, const char __user *buf,

• 		size_t count, loff_t *ppos)
  

+{

• char *p, *data, *data_ptr_res;
• unsigned long vaddr;
• struct mm_struct *mm = file->private_data;
• struct page *page;
• LIST_HEAD(pagelist);
• int ret = 0;
• if (!mm || !mmget_not_zero(mm)) {

• ret = -ESRCH;
  

• goto out;
  

• }
• if (count < 0) {

• ret = -EOPNOTSUPP;
  

• goto out_mm;
  

• }
• data = memdup_user_nul(buf, count);
• if (IS_ERR(data)) {

• ret = PTR_ERR(data);
  

• goto out_mm;
  

• }
• data_ptr_res = data;
• while ((p = strsep(&data, "\n")) != NULL) {

• if (!*p)
  

• 	continue;
  

• ret = kstrtoul(p, 16, &vaddr);
  

• if (ret != 0)
  

• 	continue;
  

• /* If get page struct failed, ignore it, get next page */
  

• page = get_page_from_vaddr(mm, vaddr);
  

• if (!page)
  

• 	continue;
  

• add_page_for_swap(page, &pagelist);
  

• }
• if (!list_empty(&pagelist))

• reclaim_pages(&pagelist);
  

• ret = count;
• kfree(data_ptr_res);

+out_mm:

• mmput(mm);

+out:

• return ret;

+}

+static int swap_pages_open(struct inode *inode, struct file *file) +{

• if (!try_module_get(THIS_MODULE))

• return -EBUSY;
  

• return 0;

+}

+static int swap_pages_release(struct inode *inode, struct file *file) +{

• module_put(THIS_MODULE);
• return 0;

+}

+extern struct file_operations proc_swap_pages_operations;

+static int swap_pages_entry(void) +{

• proc_swap_pages_operations.flock(NULL, 1, NULL);
• proc_swap_pages_operations.owner = THIS_MODULE;
• proc_swap_pages_operations.write = swap_pages_write;
• proc_swap_pages_operations.open = swap_pages_open;
• proc_swap_pages_operations.release = swap_pages_release;
• proc_swap_pages_operations.flock(NULL, 0, NULL);
• return 0;

+}

+static void swap_pages_exit(void) +{

• proc_swap_pages_operations.flock(NULL, 1, NULL);
• proc_swap_pages_operations.owner = NULL;
• proc_swap_pages_operations.write = NULL;
• proc_swap_pages_operations.open = NULL;
• proc_swap_pages_operations.release = NULL;
• proc_swap_pages_operations.flock(NULL, 0, NULL);

+}

+MODULE_LICENSE("GPL"); +module_init(swap_pages_entry); +module_exit(swap_pages_exit); diff --git a/fs/proc/internal.h b/fs/proc/internal.h index a9615455b709..be6d5dfc330c 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -305,6 +305,7 @@ extern const struct file_operations proc_clear_refs_operations; extern const struct file_operations proc_pagemap_operations; #ifdef CONFIG_ETMEM extern const struct file_operations proc_mm_idle_operations; +extern const struct file_operations proc_mm_swap_operations; #endif

extern unsigned long task_vsize(struct mm_struct *); diff --git a/include/linux/etmem.h b/include/linux/etmem.h index e8a2585f3891..5ebd1c3274b7 100644 --- a/include/linux/etmem.h +++ b/include/linux/etmem.h @@ -22,6 +22,19 @@ static inline struct kvm *mm_kvm(struct mm_struct *mm) } #endif

+extern int add_page_for_swap(struct page *page, struct list_head *pagelist); +extern struct page *get_page_from_vaddr(struct mm_struct *mm,

• 			unsigned long vaddr);
  

+#else /* !CONFIG_ETMEM */ +static inline int add_page_for_swap(struct page *page, struct list_head *pagelist) +{

• return 0;

+}

+static inline struct page *get_page_from_vaddr(struct mm_struct *mm,

• 			unsigned long vaddr)
  

+{

• return NULL;

+} #endif /* #ifdef CONFIG_ETMEM */ #endif /* define __MM_ETMEM_H_ */ diff --git a/mm/Kconfig b/mm/Kconfig index 980eaf75d87b..57818763e3c7 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1359,6 +1359,16 @@ config ETMEM_SCAN scan results back to user space. etmem scan also supports virtual machine

+config ETMEM_SWAP

• tristate "module: etmem page swap for etmem support"
• depends on ETMEM
• help

•  etmem swap is a critical component of the etmem feature.
  

•  When using etmem slide engine, etmem_swap.ko will add appointed pages
  

•  (ideally all of which are all rarely used, "cold" pages) to swapcache
  

•  proactively, which will later be reclaimed and added to swap space,
  

•  making room for more frequently used, "hot" pages.
  

• config ETMEM bool "Enable etmem feature" depends on MMU

diff --git a/mm/Makefile b/mm/Makefile index 6759053ed782..3d15ba814dd7 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -142,5 +142,6 @@ obj-$(CONFIG_GENERIC_IOREMAP) += ioremap.o obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o obj-$(CONFIG_SHARE_POOL) += share_pool.o obj-$(CONFIG_MEMCG_MEMFS_INFO) += memcg_memfs_info.o +obj-$(CONFIG_ETMEM) += etmem.o obj-$(CONFIG_PAGE_CACHE_LIMIT) += page_cache_limit.o obj-$(CONFIG_CLEAR_FREELIST_PAGE) += clear_freelist_page.o diff --git a/mm/etmem.c b/mm/etmem.c new file mode 100644 index 000000000000..9a89bfcc1058 --- /dev/null +++ b/mm/etmem.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/pagemap.h> +#include <linux/memcontrol.h> +#include <linux/gfp.h> +#include <linux/mm_inline.h> +#include <linux/sysctl.h> +#include <linux/etmem.h> +#include "internal.h"

+int add_page_for_swap(struct page *page, struct list_head *pagelist) +{

• int err = -EBUSY;
• struct page *head;

struct folio *folio;

• /* If the page is mapped by more than one process, do not swap it */
• if (page_mapcount(page) > 1)

• return -EACCES;
  

folio = page_folio(page); if (folio_test_hugetlb) return xx; if (!folio_isolate_lru(folio)) { folio_put(); } xxx包括下面的page函数或者api

这个函数应该都转成folio的；不过随你们了；

• if (PageHuge(page))

• return -EACCES;
  

• head = compound_head(page);
• if (!folio_isolate_lru(page_folio(head))) {

• put_page(page);
  

• return err;
  

• }
• put_page(page);
• if (PageUnevictable(page))

• putback_lru_page(page);
  

• else

• list_add_tail(&head->lru, pagelist);
  

• err = 0;
• return err;

+} +EXPORT_SYMBOL_GPL(add_page_for_swap);

+struct page *get_page_from_vaddr(struct mm_struct *mm, unsigned long vaddr) +{

• struct page *page;
• struct vm_area_struct *vma;
• unsigned int follflags;
• mmap_read_lock(mm);
• vma = find_vma(mm, vaddr);
• if (!vma || vaddr < vma->vm_start || vma->vm_flags & VM_LOCKED) {

• mmap_read_unlock(mm);
  

• return NULL;
  

• }
• follflags = FOLL_GET | FOLL_DUMP;
• page = follow_page(vma, vaddr, follflags);
• if (IS_ERR(page) || !page) {

• mmap_read_unlock(mm);
  

• return NULL;
  

• }
• mmap_read_unlock(mm);
• return page;

+} +EXPORT_SYMBOL_GPL(get_page_from_vaddr);