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Message-Id: <20211224062246.1258487-9-hch@lst.de>
Date: Fri, 24 Dec 2021 07:22:41 +0100
From: Christoph Hellwig <hch@....de>
To: Andrew Morton <akpm@...ux-foundation.org>,
Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: Hugh Dickins <hughd@...gle.com>,
Seth Jennings <sjenning@...hat.com>,
Dan Streetman <ddstreet@...e.org>,
Vitaly Wool <vitaly.wool@...sulko.com>,
Matthew Wilcox <willy@...radead.org>,
linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-mm@...ck.org
Subject: [PATCH 08/13] 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.
Signed-off-by: Christoph Hellwig <hch@....de>
---
include/linux/frontswap.h | 7 ----
include/linux/shmem_fs.h | 3 +-
include/linux/swapfile.h | 1 -
mm/shmem.c | 33 +++-------------
mm/swapfile.c | 83 +++++++++++----------------------------
5 files changed, 30 insertions(+), 97 deletions(-)
diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h
index 73d7beb44f2b7..a9817d4fa74c1 100644
--- a/include/linux/frontswap.h
+++ b/include/linux/frontswap.h
@@ -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 */
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 166158b6e917a..e65b80ed09e77 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -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);
diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h
index e06febf629788..809cd01ef2c57 100644
--- a/include/linux/swapfile.h
+++ b/include/linux/swapfile.h
@@ -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);
diff --git a/mm/shmem.c b/mm/shmem.c
index eb0fd90011308..421b2459929a2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -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>
@@ -1146,7 +1145,7 @@ 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;
@@ -1167,9 +1166,6 @@ 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;
@@ -1222,26 +1218,20 @@ 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;
@@ -1251,14 +1241,6 @@ 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);
@@ -1270,8 +1252,7 @@ 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;
@@ -1294,8 +1275,7 @@ 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);
@@ -4009,8 +3989,7 @@ 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, unsigned long *fs_pages_to_unuse)
{
return 0;
}
diff --git a/mm/swapfile.c b/mm/swapfile.c
index df5930ccd93dd..82342c77791bb 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -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;
@@ -2124,8 +2105,7 @@ 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;
+ 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) {
--
2.30.2
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