On 2023/8/26 03:04, Mike Kravetz wrote:
From: Joao Martins <joao.m.martins@xxxxxxxxxx>
Now that a list of pages is deduplicated at once, the TLB
flush can be batched for all vmemmap pages that got remapped.
Add a flags field and pass whether it's a bulk allocation or
just a single page to decide to remap.
The TLB flush is global as we don't have guarantees from caller
that the set of folios is contiguous, or to add complexity in
composing a list of kVAs to flush.
Modified by Mike Kravetz to perform TLB flush on single folio if an
error is encountered.
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
mm/hugetlb_vmemmap.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index 904a64fe5669..a2fc7b03ac6b 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -36,6 +36,7 @@ struct vmemmap_remap_walk {
unsigned long reuse_addr;
struct list_head *vmemmap_pages;
#define VMEMMAP_REMAP_ONLY_SPLIT BIT(0)
+#define VMEMMAP_REMAP_BULK_PAGES BIT(1)
We could reuse the flag (as I suggest VMEMMAP_SPLIT_WITHOUT_FLUSH)
proposed in the patch 10. When I saw this patch, I think the name
is not suitable, maybe VMEMMAP_WITHOUT_TLB_FLUSH is better.
Thanks.
unsigned long flags;
};
@@ -211,7 +212,8 @@ static int vmemmap_remap_range(unsigned long start, unsigned long end,
return ret;
} while (pgd++, addr = next, addr != end);
- if (!(walk->flags & VMEMMAP_REMAP_ONLY_SPLIT))
+ if (!(walk->flags &
+ (VMEMMAP_REMAP_ONLY_SPLIT | VMEMMAP_REMAP_BULK_PAGES)))
flush_tlb_kernel_range(start, end);
return 0;
@@ -377,7 +379,7 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
.remap_pte = vmemmap_remap_pte,
.reuse_addr = reuse,
.vmemmap_pages = &vmemmap_pages,
- .flags = 0,
+ .flags = !bulk_pages ? 0 : VMEMMAP_REMAP_BULK_PAGES,
};
int nid = page_to_nid((struct page *)start);
gfp_t gfp_mask = GFP_KERNEL | __GFP_THISNODE | __GFP_NORETRY |
@@ -427,6 +429,7 @@ static int vmemmap_remap_free(unsigned long start, unsigned long end,
.remap_pte = vmemmap_restore_pte,
.reuse_addr = reuse,
.vmemmap_pages = &vmemmap_pages,
+ .flags = 0,
};
vmemmap_remap_range(reuse, end, &walk);
@@ -700,6 +703,8 @@ void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_l
list_for_each_entry(folio, folio_list, lru)
hugetlb_vmemmap_optimize_bulk(h, &folio->page, &vmemmap_pages);
+ flush_tlb_kernel_range(0, TLB_FLUSH_ALL);
+
free_vmemmap_page_list(&vmemmap_pages);
}
