The patch titled
Subject: swap: turn get_swap_page() into folio_alloc_swap()
has been added to the -mm mm-unstable branch. Its filename is
swap-turn-get_swap_page-into-folio_alloc_swap.patch
This patch should soon appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: swap: turn get_swap_page() into folio_alloc_swap()
This removes an assumption that a large folio is HPAGE_PMD_NR pages in
size.
Link: https://lkml.kernel.org/r/20220429192329.3034378-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 13 +++++++------
mm/memcontrol.c | 16 ++++++++--------
mm/shmem.c | 3 ++-
mm/swap_slots.c | 14 +++++++-------
mm/swap_state.c | 3 ++-
mm/swapfile.c | 17 +++++++++--------
6 files changed, 35 insertions(+), 31 deletions(-)
--- a/include/linux/swap.h~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/include/linux/swap.h
@@ -475,7 +475,7 @@ static inline long get_nr_swap_pages(voi
}
extern void si_swapinfo(struct sysinfo *);
-extern swp_entry_t get_swap_page(struct page *page);
+swp_entry_t folio_alloc_swap(struct folio *folio);
extern void put_swap_page(struct page *page, swp_entry_t entry);
extern swp_entry_t get_swap_page_of_type(int);
extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
@@ -588,7 +588,7 @@ static inline int try_to_free_swap(struc
return 0;
}
-static inline swp_entry_t get_swap_page(struct page *page)
+static inline swp_entry_t folio_alloc_swap(struct folio *folio)
{
swp_entry_t entry;
entry.val = 0;
@@ -648,12 +648,13 @@ static inline void cgroup_throttle_swapr
#ifdef CONFIG_MEMCG_SWAP
void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry);
-extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
-static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry);
+static inline int mem_cgroup_try_charge_swap(struct folio *folio,
+ swp_entry_t entry)
{
if (mem_cgroup_disabled())
return 0;
- return __mem_cgroup_try_charge_swap(page, entry);
+ return __mem_cgroup_try_charge_swap(folio, entry);
}
extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
@@ -671,7 +672,7 @@ static inline void mem_cgroup_swapout(st
{
}
-static inline int mem_cgroup_try_charge_swap(struct page *page,
+static inline int mem_cgroup_try_charge_swap(struct folio *folio,
swp_entry_t entry)
{
return 0;
--- a/mm/memcontrol.c~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/mm/memcontrol.c
@@ -7162,17 +7162,17 @@ void mem_cgroup_swapout(struct folio *fo
}
/**
- * __mem_cgroup_try_charge_swap - try charging swap space for a page
- * @page: page being added to swap
+ * __mem_cgroup_try_charge_swap - try charging swap space for a folio
+ * @folio: folio being added to swap
* @entry: swap entry to charge
*
- * Try to charge @page's memcg for the swap space at @entry.
+ * Try to charge @folio's memcg for the swap space at @entry.
*
* Returns 0 on success, -ENOMEM on failure.
*/
-int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry)
{
- unsigned int nr_pages = thp_nr_pages(page);
+ unsigned int nr_pages = folio_nr_pages(folio);
struct page_counter *counter;
struct mem_cgroup *memcg;
unsigned short oldid;
@@ -7180,9 +7180,9 @@ int __mem_cgroup_try_charge_swap(struct
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
return 0;
- memcg = page_memcg(page);
+ memcg = folio_memcg(folio);
- VM_WARN_ON_ONCE_PAGE(!memcg, page);
+ VM_WARN_ON_ONCE_FOLIO(!memcg, folio);
if (!memcg)
return 0;
@@ -7205,7 +7205,7 @@ int __mem_cgroup_try_charge_swap(struct
if (nr_pages > 1)
mem_cgroup_id_get_many(memcg, nr_pages - 1);
oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages);
- VM_BUG_ON_PAGE(oldid, page);
+ VM_BUG_ON_FOLIO(oldid, folio);
mod_memcg_state(memcg, MEMCG_SWAP, nr_pages);
return 0;
--- a/mm/shmem.c~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/mm/shmem.c
@@ -1313,6 +1313,7 @@ int shmem_unuse(unsigned int type)
*/
static int shmem_writepage(struct page *page, struct writeback_control *wbc)
{
+ struct folio *folio = page_folio(page);
struct shmem_inode_info *info;
struct address_space *mapping;
struct inode *inode;
@@ -1386,7 +1387,7 @@ static int shmem_writepage(struct page *
SetPageUptodate(page);
}
- swap = get_swap_page(page);
+ swap = folio_alloc_swap(folio);
if (!swap.val)
goto redirty;
--- a/mm/swapfile.c~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/mm/swapfile.c
@@ -77,9 +77,9 @@ static PLIST_HEAD(swap_active_head);
/*
* all available (active, not full) swap_info_structs
* protected with swap_avail_lock, ordered by priority.
- * This is used by get_swap_page() instead of swap_active_head
+ * This is used by folio_alloc_swap() instead of swap_active_head
* because swap_active_head includes all swap_info_structs,
- * but get_swap_page() doesn't need to look at full ones.
+ * but folio_alloc_swap() doesn't need to look at full ones.
* This uses its own lock instead of swap_lock because when a
* swap_info_struct changes between not-full/full, it needs to
* add/remove itself to/from this list, but the swap_info_struct->lock
@@ -2124,11 +2124,12 @@ retry:
* Under global memory pressure, swap entries can be reinserted back
* into process space after the mmlist loop above passes over them.
*
- * Limit the number of retries? No: when mmget_not_zero() above fails,
- * that mm is likely to be freeing swap from exit_mmap(), which proceeds
- * at its own independent pace; and even shmem_writepage() could have
- * been preempted after get_swap_page(), temporarily hiding that swap.
- * It's easy and robust (though cpu-intensive) just to keep retrying.
+ * Limit the number of retries? No: when mmget_not_zero()
+ * above fails, that mm is likely to be freeing swap from
+ * exit_mmap(), which proceeds at its own independent pace;
+ * and even shmem_writepage() could have been preempted after
+ * folio_alloc_swap(), temporarily hiding that swap. It's easy
+ * and robust (though cpu-intensive) just to keep retrying.
*/
if (READ_ONCE(si->inuse_pages)) {
if (!signal_pending(current))
@@ -2342,7 +2343,7 @@ static void _enable_swap_info(struct swa
* which on removal of any swap_info_struct with an auto-assigned
* (i.e. negative) priority increments the auto-assigned priority
* of any lower-priority swap_info_structs.
- * swap_avail_head needs to be priority ordered for get_swap_page(),
+ * swap_avail_head needs to be priority ordered for folio_alloc_swap(),
* which allocates swap pages from the highest available priority
* swap_info_struct.
*/
--- a/mm/swap_slots.c~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/mm/swap_slots.c
@@ -117,7 +117,7 @@ static int alloc_swap_slot_cache(unsigne
/*
* Do allocation outside swap_slots_cache_mutex
- * as kvzalloc could trigger reclaim and get_swap_page,
+ * as kvzalloc could trigger reclaim and folio_alloc_swap,
* which can lock swap_slots_cache_mutex.
*/
slots = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t),
@@ -213,7 +213,7 @@ static void __drain_swap_slots_cache(uns
* this function can be invoked in the cpu
* hot plug path:
* cpu_up -> lock cpu_hotplug -> cpu hotplug state callback
- * -> memory allocation -> direct reclaim -> get_swap_page
+ * -> memory allocation -> direct reclaim -> folio_alloc_swap
* -> drain_swap_slots_cache
*
* Hence the loop over current online cpu below could miss cpu that
@@ -301,16 +301,16 @@ direct_free:
return 0;
}
-swp_entry_t get_swap_page(struct page *page)
+swp_entry_t folio_alloc_swap(struct folio *folio)
{
swp_entry_t entry;
struct swap_slots_cache *cache;
entry.val = 0;
- if (PageTransHuge(page)) {
+ if (folio_test_large(folio)) {
if (IS_ENABLED(CONFIG_THP_SWAP))
- get_swap_pages(1, &entry, HPAGE_PMD_NR);
+ get_swap_pages(1, &entry, folio_nr_pages(folio));
goto out;
}
@@ -344,8 +344,8 @@ repeat:
get_swap_pages(1, &entry, 1);
out:
- if (mem_cgroup_try_charge_swap(page, entry)) {
- put_swap_page(page, entry);
+ if (mem_cgroup_try_charge_swap(folio, entry)) {
+ put_swap_page(&folio->page, entry);
entry.val = 0;
}
return entry;
--- a/mm/swap_state.c~swap-turn-get_swap_page-into-folio_alloc_swap
+++ a/mm/swap_state.c
@@ -184,13 +184,14 @@ void __delete_from_swap_cache(struct pag
*/
int add_to_swap(struct page *page)
{
+ struct folio *folio = page_folio(page);
swp_entry_t entry;
int err;
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(!PageUptodate(page), page);
- entry = get_swap_page(page);
+ entry = folio_alloc_swap(folio);
if (!entry.val)
return 0;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
shmem-convert-shmem_alloc_hugepage-to-use-vma_alloc_folio.patch
mm-huge_memory-convert-do_huge_pmd_anonymous_page-to-use-vma_alloc_folio.patch
mm-remove-alloc_pages_vma.patch
vmscan-use-folio_mapped-in-shrink_page_list.patch
vmscan-convert-the-writeback-handling-in-shrink_page_list-to-folios.patch
swap-turn-get_swap_page-into-folio_alloc_swap.patch
swap-convert-add_to_swap-to-take-a-folio.patch
vmscan-convert-dirty-page-handling-to-folios.patch
vmscan-convert-page-buffer-handling-to-use-folios.patch
vmscan-convert-lazy-freeing-to-folios.patch
vmscan-move-initialisation-of-mapping-down.patch
vmscan-convert-the-activate_locked-portion-of-shrink_page_list-to-folios.patch
vmscan-remove-remaining-uses-of-page-in-shrink_page_list.patch
mm-shmem-use-a-folio-in-shmem_unused_huge_shrink.patch
mm-swap-add-folio_throttle_swaprate.patch
mm-shmem-convert-shmem_add_to_page_cache-to-take-a-folio.patch
mm-shmem-turn-shmem_should_replace_page-into-shmem_should_replace_folio.patch
mm-shmem-turn-shmem_alloc_page-into-shmem_alloc_folio.patch
mm-shmem-convert-shmem_alloc_and_acct_page-to-use-a-folio.patch
mm-shmem-convert-shmem_getpage_gfp-to-use-a-folio.patch
mm-shmem-convert-shmem_swapin_page-to-shmem_swapin_folio.patch
vmcore-convert-copy_oldmem_page-to-take-an-iov_iter.patch
vmcore-convert-__read_vmcore-to-use-an-iov_iter.patch
vmcore-convert-read_from_oldmem-to-take-an-iov_iter.patch
