Commit 10a9c496 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

mm: simplify try_to_unuse 

Remove the unused frontswap and pages_to_unuse arguments, and mark the
function static now that the caller in frontswap is gone.

[akpm@linux-foundation.org: fix shmem_unuse() stub, per Matthew]

Link: https://lkml.kernel.org/r/20211224062246.1258487-9-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 360be5da

include/linux/frontswap.h

+0 −7
Original line number Diff line number Diff line
@@ -7,13 +7,6 @@ 
#include <linux/bitops.h>

#include <linux/jump_label.h>



/*

 * Return code to denote that requested number of

 * frontswap pages are unused(moved to page cache).

 * Used in shmem_unuse and try_to_unuse.

 */

#define FRONTSWAP_PAGES_UNUSED	2



struct frontswap_ops {

	void (*init)(unsigned); /* this swap type was just swapon'ed */

	int (*store)(unsigned, pgoff_t, struct page *); /* store a page */

include/linux/shmem_fs.h

+1 −2
Original line number Diff line number Diff line
@@ -83,8 +83,7 @@ extern void shmem_unlock_mapping(struct address_space *mapping); 
extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,

					pgoff_t index, gfp_t gfp_mask);

extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);

extern int shmem_unuse(unsigned int type, bool frontswap,

		       unsigned long *fs_pages_to_unuse);

int shmem_unuse(unsigned int type);



extern bool shmem_is_huge(struct vm_area_struct *vma,

			  struct inode *inode, pgoff_t index);

include/linux/swapfile.h

+0 −1
Original line number Diff line number Diff line
@@ -9,7 +9,6 @@ 
extern spinlock_t swap_lock;

extern struct plist_head swap_active_head;

extern struct swap_info_struct *swap_info[];

extern int try_to_unuse(unsigned int, bool, unsigned long);

extern unsigned long generic_max_swapfile_size(void);

extern unsigned long max_swapfile_size(void);

mm/shmem.c

+6 −27
Original line number Diff line number Diff line
@@ -36,7 +36,6 @@ 
#include <linux/uio.h>

#include <linux/khugepaged.h>

#include <linux/hugetlb.h>

#include <linux/frontswap.h>

#include <linux/fs_parser.h>

#include <linux/swapfile.h>
@@ -1152,7 +1151,7 @@ static void shmem_evict_inode(struct inode *inode) 
static int shmem_find_swap_entries(struct address_space *mapping,

				   pgoff_t start, unsigned int nr_entries,

				   struct page **entries, pgoff_t *indices,

				   unsigned int type, bool frontswap)

				   unsigned int type)

{

	XA_STATE(xas, &mapping->i_pages, start);

	struct page *page;
@@ -1173,9 +1172,6 @@ static int shmem_find_swap_entries(struct address_space *mapping, 
		entry = radix_to_swp_entry(page);

		if (swp_type(entry) != type)

			continue;

		if (frontswap &&

		    !frontswap_test(swap_info[type], swp_offset(entry)))

			continue;



		indices[ret] = xas.xa_index;

		entries[ret] = page;
@@ -1228,26 +1224,20 @@ static int shmem_unuse_swap_entries(struct inode *inode, struct pagevec pvec, 
/*

 * If swap found in inode, free it and move page from swapcache to filecache.

 */

static int shmem_unuse_inode(struct inode *inode, unsigned int type,

			     bool frontswap, unsigned long *fs_pages_to_unuse)

static int shmem_unuse_inode(struct inode *inode, unsigned int type)

{

	struct address_space *mapping = inode->i_mapping;

	pgoff_t start = 0;

	struct pagevec pvec;

	pgoff_t indices[PAGEVEC_SIZE];

	bool frontswap_partial = (frontswap && *fs_pages_to_unuse > 0);

	int ret = 0;



	pagevec_init(&pvec);

	do {

		unsigned int nr_entries = PAGEVEC_SIZE;



		if (frontswap_partial && *fs_pages_to_unuse < PAGEVEC_SIZE)

			nr_entries = *fs_pages_to_unuse;



		pvec.nr = shmem_find_swap_entries(mapping, start, nr_entries,

						  pvec.pages, indices,

						  type, frontswap);

						  pvec.pages, indices, type);

		if (pvec.nr == 0) {

			ret = 0;

			break;
@@ -1257,14 +1247,6 @@ static int shmem_unuse_inode(struct inode *inode, unsigned int type, 
		if (ret < 0)

			break;



		if (frontswap_partial) {

			*fs_pages_to_unuse -= ret;

			if (*fs_pages_to_unuse == 0) {

				ret = FRONTSWAP_PAGES_UNUSED;

				break;

			}

		}



		start = indices[pvec.nr - 1];

	} while (true);
@@ -1276,8 +1258,7 @@ static int shmem_unuse_inode(struct inode *inode, unsigned int type, 
 * device 'type' back into memory, so the swap device can be

 * unused.

 */

int shmem_unuse(unsigned int type, bool frontswap,

		unsigned long *fs_pages_to_unuse)

int shmem_unuse(unsigned int type)

{

	struct shmem_inode_info *info, *next;

	int error = 0;
@@ -1300,8 +1281,7 @@ int shmem_unuse(unsigned int type, bool frontswap, 
		atomic_inc(&info->stop_eviction);

		mutex_unlock(&shmem_swaplist_mutex);



		error = shmem_unuse_inode(&info->vfs_inode, type, frontswap,

					  fs_pages_to_unuse);

		error = shmem_unuse_inode(&info->vfs_inode, type);

		cond_resched();



		mutex_lock(&shmem_swaplist_mutex);
@@ -4015,8 +3995,7 @@ int __init shmem_init(void) 
	return 0;

}



int shmem_unuse(unsigned int type, bool frontswap,

		unsigned long *fs_pages_to_unuse)

int shmem_unuse(unsigned int type)

{

	return 0;

}

mm/swapfile.c

+23 −60
Original line number Diff line number Diff line
@@ -1923,8 +1923,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, 


static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,

			unsigned long addr, unsigned long end,

			unsigned int type, bool frontswap,

			unsigned long *fs_pages_to_unuse)

			unsigned int type)

{

	struct page *page;

	swp_entry_t entry;
@@ -1945,9 +1944,6 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 
			continue;



		offset = swp_offset(entry);

		if (frontswap && !frontswap_test(si, offset))

			continue;



		pte_unmap(pte);

		swap_map = &si->swap_map[offset];

		page = lookup_swap_cache(entry, vma, addr);
@@ -1979,11 +1975,6 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 
		try_to_free_swap(page);

		unlock_page(page);

		put_page(page);



		if (*fs_pages_to_unuse && !--(*fs_pages_to_unuse)) {

			ret = FRONTSWAP_PAGES_UNUSED;

			goto out;

		}

try_next:

		pte = pte_offset_map(pmd, addr);

	} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1996,8 +1987,7 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 


static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,

				unsigned long addr, unsigned long end,

				unsigned int type, bool frontswap,

				unsigned long *fs_pages_to_unuse)

				unsigned int type)

{

	pmd_t *pmd;

	unsigned long next;
@@ -2009,8 +1999,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, 
		next = pmd_addr_end(addr, end);

		if (pmd_none_or_trans_huge_or_clear_bad(pmd))

			continue;

		ret = unuse_pte_range(vma, pmd, addr, next, type,

				      frontswap, fs_pages_to_unuse);

		ret = unuse_pte_range(vma, pmd, addr, next, type);

		if (ret)

			return ret;

	} while (pmd++, addr = next, addr != end);
@@ -2019,8 +2008,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud, 


static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d,

				unsigned long addr, unsigned long end,

				unsigned int type, bool frontswap,

				unsigned long *fs_pages_to_unuse)

				unsigned int type)

{

	pud_t *pud;

	unsigned long next;
@@ -2031,8 +2019,7 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d, 
		next = pud_addr_end(addr, end);

		if (pud_none_or_clear_bad(pud))

			continue;

		ret = unuse_pmd_range(vma, pud, addr, next, type,

				      frontswap, fs_pages_to_unuse);

		ret = unuse_pmd_range(vma, pud, addr, next, type);

		if (ret)

			return ret;

	} while (pud++, addr = next, addr != end);
@@ -2041,8 +2028,7 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d, 


static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd,

				unsigned long addr, unsigned long end,

				unsigned int type, bool frontswap,

				unsigned long *fs_pages_to_unuse)

				unsigned int type)

{

	p4d_t *p4d;

	unsigned long next;
@@ -2053,16 +2039,14 @@ static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd, 
		next = p4d_addr_end(addr, end);

		if (p4d_none_or_clear_bad(p4d))

			continue;

		ret = unuse_pud_range(vma, p4d, addr, next, type,

				      frontswap, fs_pages_to_unuse);

		ret = unuse_pud_range(vma, p4d, addr, next, type);

		if (ret)

			return ret;

	} while (p4d++, addr = next, addr != end);

	return 0;

}



static int unuse_vma(struct vm_area_struct *vma, unsigned int type,

		     bool frontswap, unsigned long *fs_pages_to_unuse)

static int unuse_vma(struct vm_area_struct *vma, unsigned int type)

{

	pgd_t *pgd;

	unsigned long addr, end, next;
@@ -2076,16 +2060,14 @@ static int unuse_vma(struct vm_area_struct *vma, unsigned int type, 
		next = pgd_addr_end(addr, end);

		if (pgd_none_or_clear_bad(pgd))

			continue;

		ret = unuse_p4d_range(vma, pgd, addr, next, type,

				      frontswap, fs_pages_to_unuse);

		ret = unuse_p4d_range(vma, pgd, addr, next, type);

		if (ret)

			return ret;

	} while (pgd++, addr = next, addr != end);

	return 0;

}



static int unuse_mm(struct mm_struct *mm, unsigned int type,

		    bool frontswap, unsigned long *fs_pages_to_unuse)

static int unuse_mm(struct mm_struct *mm, unsigned int type)

{

	struct vm_area_struct *vma;

	int ret = 0;
@@ -2093,8 +2075,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type, 
	mmap_read_lock(mm);

	for (vma = mm->mmap; vma; vma = vma->vm_next) {

		if (vma->anon_vma) {

			ret = unuse_vma(vma, type, frontswap,

					fs_pages_to_unuse);

			ret = unuse_vma(vma, type);

			if (ret)

				break;

		}
@@ -2110,7 +2091,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type, 
 * if there are no inuse entries after prev till end of the map.

 */

static unsigned int find_next_to_unuse(struct swap_info_struct *si,

					unsigned int prev, bool frontswap)

					unsigned int prev)

{

	unsigned int i;

	unsigned char count;
@@ -2124,7 +2105,6 @@ static unsigned int find_next_to_unuse(struct swap_info_struct *si, 
	for (i = prev + 1; i < si->max; i++) {

		count = READ_ONCE(si->swap_map[i]);

		if (count && swap_count(count) != SWAP_MAP_BAD)

			if (!frontswap || frontswap_test(si, i))

			break;

		if ((i % LATENCY_LIMIT) == 0)

			cond_resched();
@@ -2136,12 +2116,7 @@ static unsigned int find_next_to_unuse(struct swap_info_struct *si, 
	return i;

}



/*

 * If the boolean frontswap is true, only unuse pages_to_unuse pages;

 * pages_to_unuse==0 means all pages; ignored if frontswap is false

 */

int try_to_unuse(unsigned int type, bool frontswap,

		 unsigned long pages_to_unuse)

static int try_to_unuse(unsigned int type)

{

	struct mm_struct *prev_mm;

	struct mm_struct *mm;
@@ -2155,13 +2130,10 @@ int try_to_unuse(unsigned int type, bool frontswap, 
	if (!READ_ONCE(si->inuse_pages))

		return 0;



	if (!frontswap)

		pages_to_unuse = 0;



retry:

	retval = shmem_unuse(type, frontswap, &pages_to_unuse);

	retval = shmem_unuse(type);

	if (retval)

		goto out;

		return retval;



	prev_mm = &init_mm;

	mmget(prev_mm);
@@ -2178,11 +2150,10 @@ int try_to_unuse(unsigned int type, bool frontswap, 
		spin_unlock(&mmlist_lock);

		mmput(prev_mm);

		prev_mm = mm;

		retval = unuse_mm(mm, type, frontswap, &pages_to_unuse);



		retval = unuse_mm(mm, type);

		if (retval) {

			mmput(prev_mm);

			goto out;

			return retval;

		}



		/*
@@ -2199,7 +2170,7 @@ int try_to_unuse(unsigned int type, bool frontswap, 
	i = 0;

	while (READ_ONCE(si->inuse_pages) &&

	       !signal_pending(current) &&

	       (i = find_next_to_unuse(si, i, frontswap)) != 0) {

	       (i = find_next_to_unuse(si, i)) != 0) {



		entry = swp_entry(type, i);

		page = find_get_page(swap_address_space(entry), i);
@@ -2217,14 +2188,6 @@ int try_to_unuse(unsigned int type, bool frontswap, 
		try_to_free_swap(page);

		unlock_page(page);

		put_page(page);



		/*

		 * For frontswap, we just need to unuse pages_to_unuse, if

		 * it was specified. Need not check frontswap again here as

		 * we already zeroed out pages_to_unuse if not frontswap.

		 */

		if (pages_to_unuse && --pages_to_unuse == 0)

			goto out;

	}



	/*
@@ -2242,10 +2205,10 @@ int try_to_unuse(unsigned int type, bool frontswap, 
	if (READ_ONCE(si->inuse_pages)) {

		if (!signal_pending(current))

			goto retry;

		retval = -EINTR;

		return -EINTR;

	}

out:

	return (retval == FRONTSWAP_PAGES_UNUSED) ? 0 : retval;



	return 0;

}



/*
@@ -2577,7 +2540,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) 
	disable_swap_slots_cache_lock();



	set_current_oom_origin();

	err = try_to_unuse(p->type, false, 0); /* force unuse all pages */

	err = try_to_unuse(p->type);

	clear_current_oom_origin();



	if (err) {