From: Zi Yan <ziy@xxxxxxxxxx>
This prepares for the following patches to provide a user API to
manipulate pages in two memory nodes with the help of memcg.
missing memcg_max_size_node()
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
include/linux/sched/coredump.h | 1 +
include/linux/syscalls.h | 5 ++
include/uapi/linux/mempolicy.h | 1 +
mm/Makefile | 1 +
mm/internal.h | 2 +
mm/memory_manage.c | 109 +++++++++++++++++++++++++++++++++
mm/mempolicy.c | 2 +-
8 files changed, 121 insertions(+), 1 deletion(-)
create mode 100644 mm/memory_manage.c
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 863a21e..fa8def3 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -344,6 +344,7 @@
333 common io_pgetevents __x64_sys_io_pgetevents
334 common rseq __x64_sys_rseq
335 common exchange_pages __x64_sys_exchange_pages
+336 common mm_manage __x64_sys_mm_manage
# don't use numbers 387 through 423, add new calls after the last
# 'common' entry
424 common pidfd_send_signal __x64_sys_pidfd_send_signal
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index ecdc654..9aa9d94b 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -73,6 +73,7 @@ static inline int get_dumpable(struct mm_struct *mm)
#define MMF_OOM_VICTIM 25 /* mm is the oom victim */
#define MMF_OOM_REAP_QUEUED 26 /* mm was queued for oom_reaper */
#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP)
+#define MMF_MM_MANAGE 27
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
MMF_DISABLE_THP_MASK)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 2c1eb49..47d56c5 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -1208,6 +1208,11 @@ asmlinkage long sys_exchange_pages(pid_t pid, unsigned long nr_pages,
const void __user * __user *to_pages,
int __user *status,
int flags);
+asmlinkage long sys_mm_manage(pid_t pid, unsigned long nr_pages,
+ unsigned long maxnode,
+ const unsigned long __user *old_nodes,
+ const unsigned long __user *new_nodes,
+ int flags);
/*
* Not a real system call, but a placeholder for syscalls which are
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index a9d03e5..4722bb7 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -52,6 +52,7 @@ enum {
#define MPOL_MF_MOVE_DMA (1<<5) /* Use DMA page copy routine */
#define MPOL_MF_MOVE_MT (1<<6) /* Use multi-threaded page copy routine */
#define MPOL_MF_MOVE_CONCUR (1<<7) /* Move pages in a batch */
+#define MPOL_MF_EXCHANGE (1<<8) /* Exchange pages */
#define MPOL_MF_VALID (MPOL_MF_STRICT | \
MPOL_MF_MOVE | \
diff --git a/mm/Makefile b/mm/Makefile
index 2f1f1ad..5302d79 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -47,6 +47,7 @@ obj-y += memblock.o
obj-y += copy_page.o
obj-y += exchange.o
obj-y += exchange_page.o
+obj-y += memory_manage.o
ifdef CONFIG_MMU
obj-$(CONFIG_ADVISE_SYSCALLS) += madvise.o
diff --git a/mm/internal.h b/mm/internal.h
index cf63bf6..94feb14 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -574,5 +574,7 @@ bool buffer_migrate_lock_buffers(struct buffer_head *head,
int writeout(struct address_space *mapping, struct page *page);
int expected_page_refs(struct address_space *mapping, struct page *page);
+int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
+ unsigned long maxnode);
#endif /* __MM_INTERNAL_H */
diff --git a/mm/memory_manage.c b/mm/memory_manage.c
new file mode 100644
index 0000000..b8f3654
--- /dev/null
+++ b/mm/memory_manage.c
@@ -0,0 +1,109 @@
+/*
+ * A syscall used to move pages between two nodes.
+ */
+
+#include <linux/sched/mm.h>
+#include <linux/cpuset.h>
+#include <linux/mempolicy.h>
+#include <linux/nodemask.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+
+#include "internal.h"
+
+
+SYSCALL_DEFINE6(mm_manage, pid_t, pid, unsigned long, nr_pages,
+ unsigned long, maxnode,
+ const unsigned long __user *, slow_nodes,
+ const unsigned long __user *, fast_nodes,
+ int, flags)
+{
+ const struct cred *cred = current_cred(), *tcred;
+ struct task_struct *task;
+ struct mm_struct *mm = NULL;
+ int err;
+ nodemask_t task_nodes;
+ nodemask_t *slow;
+ nodemask_t *fast;
+ NODEMASK_SCRATCH(scratch);
+
+ if (!scratch)
+ return -ENOMEM;
+
+ slow = &scratch->mask1;
+ fast = &scratch->mask2;
+
+ err = get_nodes(slow, slow_nodes, maxnode);
+ if (err)
+ goto out;
+
+ err = get_nodes(fast, fast_nodes, maxnode);
+ if (err)
+ goto out;
+
+ /* Check flags */
+ if (flags & ~(MPOL_MF_MOVE_MT|
+ MPOL_MF_MOVE_DMA|
+ MPOL_MF_MOVE_CONCUR|
+ MPOL_MF_EXCHANGE))
+ return -EINVAL;
+
+ /* Find the mm_struct */
+ rcu_read_lock();
+ task = pid ? find_task_by_vpid(pid) : current;
+ if (!task) {
+ rcu_read_unlock();
+ err = -ESRCH;
+ goto out;
+ }
+ get_task_struct(task);
+
+ err = -EINVAL;
+ /*
+ * Check if this process has the right to modify the specified
+ * process. The right exists if the process has administrative
+ * capabilities, superuser privileges or the same
+ * userid as the target process.
+ */
+ tcred = __task_cred(task);
+ if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
+ !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) &&
+ !capable(CAP_SYS_NICE)) {
+ rcu_read_unlock();
+ err = -EPERM;
+ goto out_put;
+ }
+ rcu_read_unlock();
+
+ err = security_task_movememory(task);
+ if (err)
+ goto out_put;
+
+ task_nodes = cpuset_mems_allowed(task);
+ mm = get_task_mm(task);
+ put_task_struct(task);
+
+ if (!mm) {
+ err = -EINVAL;
+ goto out;
+ }
+ if (test_bit(MMF_MM_MANAGE, &mm->flags)) {
+ mmput(mm);
+ goto out;
+ } else {
+ set_bit(MMF_MM_MANAGE, &mm->flags);
+ }
+
+
+ clear_bit(MMF_MM_MANAGE, &mm->flags);
+ mmput(mm);
+out:
+ NODEMASK_SCRATCH_FREE(scratch);
+
+ return err;
+
+out_put:
+ put_task_struct(task);
+ goto out;
+
+}
\ No newline at end of file
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0e30049..168d17f8 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1249,7 +1249,7 @@ static long do_mbind(unsigned long start, unsigned long len,
*/
/* Copy a node mask from user space. */
-static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
+int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
unsigned long maxnode)
{
unsigned long k;
--
2.7.4
