The patch titled
Subject: swap: fold swap_ra_clamp_pfn into swap_ra_info
has been added to the -mm mm-unstable branch. Its filename is
swap-fold-swap_ra_clamp_pfn-into-swap_ra_info.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/swap-fold-swap_ra_clamp_pfn-into-swap_ra_info.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kairui Song <kasong@xxxxxxxxxxx>
Subject: swap: fold swap_ra_clamp_pfn into swap_ra_info
Date: Tue, 20 Dec 2022 02:58:39 +0800
This makes the code cleaner. This helper is made of only two line of self
explanational code and not reused anywhere else.
And this actually make the compiled object smaller by a bit.
bloat-o-meter results on x86_64 of mm/swap_state.o:
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-35 (-35)
Function old new delta
swap_ra_info.constprop 512 477 -35
Total: Before=8388, After=8353, chg -0.42%
Link: https://lkml.kernel.org/r/20221219185840.25441-4-ryncsn@xxxxxxxxx
Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swap_state.c | 44 +++++++++++++++++++-------------------------
1 file changed, 19 insertions(+), 25 deletions(-)
--- a/mm/swap_state.c~swap-fold-swap_ra_clamp_pfn-into-swap_ra_info
+++ a/mm/swap_state.c
@@ -693,28 +693,15 @@ void exit_swap_address_space(unsigned in
swapper_spaces[type] = NULL;
}
-static inline void swap_ra_clamp_pfn(struct vm_area_struct *vma,
- unsigned long faddr,
- unsigned long lpfn,
- unsigned long rpfn,
- unsigned long *start,
- unsigned long *end)
-{
- *start = max3(lpfn, PFN_DOWN(vma->vm_start),
- PFN_DOWN(faddr & PMD_MASK));
- *end = min3(rpfn, PFN_DOWN(vma->vm_end),
- PFN_DOWN((faddr & PMD_MASK) + PMD_SIZE));
-}
-
static void swap_ra_info(struct vm_fault *vmf,
- struct vma_swap_readahead *ra_info)
+ struct vma_swap_readahead *ra_info)
{
struct vm_area_struct *vma = vmf->vma;
unsigned long ra_val;
- unsigned long faddr, pfn, fpfn;
+ unsigned long faddr, pfn, fpfn, lpfn, rpfn;
unsigned long start, end;
pte_t *pte, *orig_pte;
- unsigned int max_win, hits, prev_win, win, left;
+ unsigned int max_win, hits, prev_win, win;
#ifndef CONFIG_64BIT
pte_t *tpte;
#endif
@@ -742,16 +729,23 @@ static void swap_ra_info(struct vm_fault
/* Copy the PTEs because the page table may be unmapped */
orig_pte = pte = pte_offset_map(vmf->pmd, faddr);
- if (fpfn == pfn + 1)
- swap_ra_clamp_pfn(vma, faddr, fpfn, fpfn + win, &start, &end);
- else if (pfn == fpfn + 1)
- swap_ra_clamp_pfn(vma, faddr, fpfn - win + 1, fpfn + 1,
- &start, &end);
- else {
- left = (win - 1) / 2;
- swap_ra_clamp_pfn(vma, faddr, fpfn - left, fpfn + win - left,
- &start, &end);
+ if (fpfn == pfn + 1) {
+ lpfn = fpfn;
+ rpfn = fpfn + win;
+ } else if (pfn == fpfn + 1) {
+ lpfn = fpfn - win + 1;
+ rpfn = fpfn + 1;
+ } else {
+ unsigned int left = (win - 1) / 2;
+
+ lpfn = fpfn - left;
+ rpfn = fpfn + win - left;
}
+ start = max3(lpfn, PFN_DOWN(vma->vm_start),
+ PFN_DOWN(faddr & PMD_MASK));
+ end = min3(rpfn, PFN_DOWN(vma->vm_end),
+ PFN_DOWN((faddr & PMD_MASK) + PMD_SIZE));
+
ra_info->nr_pte = end - start;
ra_info->offset = fpfn - start;
pte -= ra_info->offset;
_
Patches currently in -mm which might be from kasong@xxxxxxxxxxx are
swapfile-get-rid-of-volatile-and-avoid-redundant-read.patch
swap-avoid-a-redundant-pte-map-if-ra-window-is-1.patch
swap-fold-swap_ra_clamp_pfn-into-swap_ra_info.patch
swap-avoid-holding-swap-reference-in-swap_cache_get_folio.patch
