lkml.org 
[lkml]   [2020]   [Sep]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 04/10] mm: allow a NULL fn callback in apply_to_page_range
Date
Besides calling the callback on each page, apply_to_page_range also has
the effect of pre-faulting all PTEs for the range. To support callers
that only need the pre-faulting, make the callback optional.

Based on a patch from Minchan Kim <minchan@kernel.org>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
mm/memory.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index fcfc4ca36eba80..dcf2bb69fbf847 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2420,13 +2420,15 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,

arch_enter_lazy_mmu_mode();

- do {
- if (create || !pte_none(*pte)) {
- err = fn(pte++, addr, data);
- if (err)
- break;
- }
- } while (addr += PAGE_SIZE, addr != end);
+ if (fn) {
+ do {
+ if (create || !pte_none(*pte)) {
+ err = fn(pte++, addr, data);
+ if (err)
+ break;
+ }
+ } while (addr += PAGE_SIZE, addr != end);
+ }
*mask |= PGTBL_PTE_MODIFIED;

arch_leave_lazy_mmu_mode();
--
2.28.0
\
 
 \ /
  Last update: 2020-09-30 19:52    [W:0.057 / U:5.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site