Commit 92a0eb9b authored by Liu Shixin's avatar Liu Shixin Committed by Jinjiang Tu
Browse files

memcg: introduce per-memcg swapin interface 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8QK6Q


CVE: NA

--------------------------------

Add a new per-memcg swapin interface to load data into memory in advance
to improve access efficiency.
Usage:
	# echo 0 > memory.force_swapin

Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
Signed-off-by: default avatarJinjiang Tu <tujinjiang@huawei.com>
parent 65b18684

Documentation/admin-guide/cgroup-v1/memory.rst

+1 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ Brief summary of control files. 
                                     This knob is deprecated and shouldn't be

                                     used.

 memory.force_empty		     trigger forced page reclaim

 memory.force_swapin		     trigger forced swapin anon page

 memory.pressure_level		     set memory pressure notifications

 memory.swappiness		     set/show swappiness parameter of vmscan

				     (See sysctl's vm.swappiness)

include/linux/mm.h

+4 −0
Original line number Diff line number Diff line
@@ -3313,6 +3313,10 @@ extern int do_munmap(struct mm_struct *, unsigned long, size_t, 
		     struct list_head *uf);

extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior);



#ifdef CONFIG_MEMCG_SWAP_QOS

extern void force_swapin_vma(struct vm_area_struct *vma);

#endif



#ifdef CONFIG_MMU

extern int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,

			 unsigned long start, unsigned long end,

mm/madvise.c

+26 −5
Original line number Diff line number Diff line
@@ -185,6 +185,11 @@ static int madvise_update_vma(struct vm_area_struct *vma, 
	return 0;

}



static inline bool can_madv_lru_vma(struct vm_area_struct *vma)

{

	return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP|VM_HUGETLB));

}



#ifdef CONFIG_SWAP

static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,

		unsigned long end, struct mm_walk *walk)
@@ -273,6 +278,27 @@ static void shmem_swapin_range(struct vm_area_struct *vma, 
}

#endif		/* CONFIG_SWAP */



#ifdef CONFIG_MEMCG_SWAP_QOS

void force_swapin_vma(struct vm_area_struct *vma)

{

	struct file *file = vma->vm_file;



	if (!can_madv_lru_vma(vma))

		return;



	if (!file) {

		walk_page_vma(vma, &swapin_walk_ops, vma);

		lru_add_drain();

	} else if (shmem_mapping(file->f_mapping))

		shmem_swapin_range(vma, vma->vm_start,

			vma->vm_end, file->f_mapping);

}

#else

void force_swapin_vma(struct vm_area_struct *vma)

{

}

#endif



/*

 * Schedule all required I/O operations.  Do not wait for completion.

 */
@@ -555,11 +581,6 @@ static void madvise_cold_page_range(struct mmu_gather *tlb, 
	tlb_end_vma(tlb, vma);

}



static inline bool can_madv_lru_vma(struct vm_area_struct *vma)

{

	return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP|VM_HUGETLB));

}



static long madvise_cold(struct vm_area_struct *vma,

			struct vm_area_struct **prev,

			unsigned long start_addr, unsigned long end_addr)

mm/memcontrol.c

+45 −0
Original line number Diff line number Diff line
@@ -66,6 +66,11 @@ 
#include <linux/memcg_memfs_info.h>

#include <linux/sched/isolation.h>

#include <linux/parser.h>



#ifdef CONFIG_MEMCG_SWAP_QOS

#include <linux/blkdev.h>

#endif



#include "internal.h"

#include <net/sock.h>

#include <net/ip.h>
@@ -4271,6 +4276,39 @@ static int sysctl_memcg_swap_qos_handler(struct ctl_table *table, int write, 
	return 0;

}

#endif



static int mem_cgroup_task_swapin(struct task_struct *task, void *arg)

{

	struct mm_struct *mm = task->mm;

	struct vm_area_struct *vma;

	struct blk_plug plug;

	VMA_ITERATOR(vmi, mm, 0);



	if (__task_is_dying(task))

		return 0;

	if (!mm || !mmget_not_zero(mm))

		return 0;



	mmap_read_lock(mm);

	blk_start_plug(&plug);

	for_each_vma(vmi, vma)

		force_swapin_vma(vma);

	blk_finish_plug(&plug);

	mmap_read_unlock(mm);

	mmput(mm);



	return 0;

}



static ssize_t memory_swapin(struct kernfs_open_file *of, char *buf,

			      size_t nbytes, loff_t off)

{

	struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));



	mem_cgroup_scan_tasks(memcg, mem_cgroup_task_swapin, NULL);



	return nbytes;

}

#endif



#ifdef CONFIG_NUMA
@@ -5762,6 +5800,13 @@ static struct cftype mem_cgroup_legacy_files[] = { 
		.write = memory_ksm_write,

		.seq_show = memory_ksm_show,

	},

#endif

#ifdef CONFIG_MEMCG_SWAP_QOS

	{

		.name = "force_swapin",

		.flags = CFTYPE_NOT_ON_ROOT,

		.write = memory_swapin,

	},

#endif

	{ },	/* terminate */

};