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Diffstat (limited to 'mm/swap_state.c')
-rw-r--r--mm/swap_state.c96
1 files changed, 53 insertions, 43 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 39ae7cfad90f..db5da2baafb1 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -332,32 +332,43 @@ struct page *lookup_swap_cache(swp_entry_t entry, struct vm_area_struct *vma,
unsigned long addr)
{
struct page *page;
- unsigned long ra_info;
- int win, hits, readahead;
page = find_get_page(swap_address_space(entry), swp_offset(entry));
INC_CACHE_INFO(find_total);
if (page) {
+ bool vma_ra = swap_use_vma_readahead();
+ bool readahead;
+
INC_CACHE_INFO(find_success);
+ /*
+ * At the moment, we don't support PG_readahead for anon THP
+ * so let's bail out rather than confusing the readahead stat.
+ */
if (unlikely(PageTransCompound(page)))
return page;
+
readahead = TestClearPageReadahead(page);
- if (vma) {
- ra_info = GET_SWAP_RA_VAL(vma);
- win = SWAP_RA_WIN(ra_info);
- hits = SWAP_RA_HITS(ra_info);
+ if (vma && vma_ra) {
+ unsigned long ra_val;
+ int win, hits;
+
+ ra_val = GET_SWAP_RA_VAL(vma);
+ win = SWAP_RA_WIN(ra_val);
+ hits = SWAP_RA_HITS(ra_val);
if (readahead)
hits = min_t(int, hits + 1, SWAP_RA_HITS_MAX);
atomic_long_set(&vma->swap_readahead_info,
SWAP_RA_VAL(addr, win, hits));
}
+
if (readahead) {
count_vm_event(SWAP_RA_HIT);
- if (!vma)
+ if (!vma || !vma_ra)
atomic_inc(&swapin_readahead_hits);
}
}
+
return page;
}
@@ -586,8 +597,7 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
continue;
if (page_allocated) {
swap_readpage(page, false);
- if (offset != entry_offset &&
- likely(!PageTransCompound(page))) {
+ if (offset != entry_offset) {
SetPageReadahead(page);
count_vm_event(SWAP_RA);
}
@@ -649,16 +659,15 @@ static inline void swap_ra_clamp_pfn(struct vm_area_struct *vma,
PFN_DOWN((faddr & PMD_MASK) + PMD_SIZE));
}
-struct page *swap_readahead_detect(struct vm_fault *vmf,
- struct vma_swap_readahead *swap_ra)
+static void swap_ra_info(struct vm_fault *vmf,
+ struct vma_swap_readahead *ra_info)
{
struct vm_area_struct *vma = vmf->vma;
- unsigned long swap_ra_info;
- struct page *page;
+ unsigned long ra_val;
swp_entry_t entry;
unsigned long faddr, pfn, fpfn;
unsigned long start, end;
- pte_t *pte;
+ pte_t *pte, *orig_pte;
unsigned int max_win, hits, prev_win, win, left;
#ifndef CONFIG_64BIT
pte_t *tpte;
@@ -667,30 +676,32 @@ struct page *swap_readahead_detect(struct vm_fault *vmf,
max_win = 1 << min_t(unsigned int, READ_ONCE(page_cluster),
SWAP_RA_ORDER_CEILING);
if (max_win == 1) {
- swap_ra->win = 1;
- return NULL;
+ ra_info->win = 1;
+ return;
}
faddr = vmf->address;
- entry = pte_to_swp_entry(vmf->orig_pte);
- if ((unlikely(non_swap_entry(entry))))
- return NULL;
- page = lookup_swap_cache(entry, vma, faddr);
- if (page)
- return page;
+ orig_pte = pte = pte_offset_map(vmf->pmd, faddr);
+ entry = pte_to_swp_entry(*pte);
+ if ((unlikely(non_swap_entry(entry)))) {
+ pte_unmap(orig_pte);
+ return;
+ }
fpfn = PFN_DOWN(faddr);
- swap_ra_info = GET_SWAP_RA_VAL(vma);
- pfn = PFN_DOWN(SWAP_RA_ADDR(swap_ra_info));
- prev_win = SWAP_RA_WIN(swap_ra_info);
- hits = SWAP_RA_HITS(swap_ra_info);
- swap_ra->win = win = __swapin_nr_pages(pfn, fpfn, hits,
+ ra_val = GET_SWAP_RA_VAL(vma);
+ pfn = PFN_DOWN(SWAP_RA_ADDR(ra_val));
+ prev_win = SWAP_RA_WIN(ra_val);
+ hits = SWAP_RA_HITS(ra_val);
+ ra_info->win = win = __swapin_nr_pages(pfn, fpfn, hits,
max_win, prev_win);
atomic_long_set(&vma->swap_readahead_info,
SWAP_RA_VAL(faddr, win, 0));
- if (win == 1)
- return NULL;
+ if (win == 1) {
+ pte_unmap(orig_pte);
+ return;
+ }
/* Copy the PTEs because the page table may be unmapped */
if (fpfn == pfn + 1)
@@ -703,23 +714,21 @@ struct page *swap_readahead_detect(struct vm_fault *vmf,
swap_ra_clamp_pfn(vma, faddr, fpfn - left, fpfn + win - left,
&start, &end);
}
- swap_ra->nr_pte = end - start;
- swap_ra->offset = fpfn - start;
- pte = vmf->pte - swap_ra->offset;
+ ra_info->nr_pte = end - start;
+ ra_info->offset = fpfn - start;
+ pte -= ra_info->offset;
#ifdef CONFIG_64BIT
- swap_ra->ptes = pte;
+ ra_info->ptes = pte;
#else
- tpte = swap_ra->ptes;
+ tpte = ra_info->ptes;
for (pfn = start; pfn != end; pfn++)
*tpte++ = *pte++;
#endif
-
- return NULL;
+ pte_unmap(orig_pte);
}
struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
- struct vm_fault *vmf,
- struct vma_swap_readahead *swap_ra)
+ struct vm_fault *vmf)
{
struct blk_plug plug;
struct vm_area_struct *vma = vmf->vma;
@@ -728,12 +737,14 @@ struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
swp_entry_t entry;
unsigned int i;
bool page_allocated;
+ struct vma_swap_readahead ra_info = {0,};
- if (swap_ra->win == 1)
+ swap_ra_info(vmf, &ra_info);
+ if (ra_info.win == 1)
goto skip;
blk_start_plug(&plug);
- for (i = 0, pte = swap_ra->ptes; i < swap_ra->nr_pte;
+ for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte;
i++, pte++) {
pentry = *pte;
if (pte_none(pentry))
@@ -749,8 +760,7 @@ struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
continue;
if (page_allocated) {
swap_readpage(page, false);
- if (i != swap_ra->offset &&
- likely(!PageTransCompound(page))) {
+ if (i != ra_info.offset) {
SetPageReadahead(page);
count_vm_event(SWAP_RA);
}
@@ -761,7 +771,7 @@ struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
lru_add_drain();
skip:
return read_swap_cache_async(fentry, gfp_mask, vma, vmf->address,
- swap_ra->win == 1);
+ ra_info.win == 1);
}
#ifdef CONFIG_SYSFS
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 18:18:43 +0000