On 2023/8/26 03:04, Mike Kravetz wrote:
Update the hugetlb_vmemmap_restore path to take a 'batch' parameter that
indicates restoration is happening on a batch of pages. When set, use
the existing mechanism (VMEMMAP_REMAP_BULK_PAGES) to delay TLB flushing.
The routine hugetlb_vmemmap_restore_folios is the only user of this new
batch parameter and it will perform a global flush after all vmemmap is
restored.
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
mm/hugetlb_vmemmap.c | 37 +++++++++++++++++++++++--------------
1 file changed, 23 insertions(+), 14 deletions(-)
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
index a2fc7b03ac6b..d6e7440b9507 100644
--- a/mm/hugetlb_vmemmap.c
+++ b/mm/hugetlb_vmemmap.c
@@ -479,17 +479,19 @@ static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
* @end: end address of the vmemmap virtual address range that we want to
* remap.
* @reuse: reuse address.
+ * @bulk: bulk operation, batch TLB flushes
*
* Return: %0 on success, negative error code otherwise.
*/
static int vmemmap_remap_alloc(unsigned long start, unsigned long end,
- unsigned long reuse)
+ unsigned long reuse, bool bulk)
I'd like to let vmemmap_remap_alloc pass VMEMMAP_REMAP_BULK_PAGES directly,
in which case, we do not need to change this function if we want to
introduce
another flag in the future. I mean that change "bool bulk" to "unsigned
long flags".
{
LIST_HEAD(vmemmap_pages);
struct vmemmap_remap_walk walk = {
.remap_pte = vmemmap_restore_pte,
.reuse_addr = reuse,
.vmemmap_pages = &vmemmap_pages,
+ .flags = !bulk ? 0 : VMEMMAP_REMAP_BULK_PAGES,
};
/* See the comment in the vmemmap_remap_free(). */
@@ -511,17 +513,7 @@ EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key);
static bool vmemmap_optimize_enabled = IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON);
core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0);
-/**
- * hugetlb_vmemmap_restore - restore previously optimized (by
- * hugetlb_vmemmap_optimize()) vmemmap pages which
- * will be reallocated and remapped.
- * @h: struct hstate.
- * @head: the head page whose vmemmap pages will be restored.
- *
- * Return: %0 if @head's vmemmap pages have been reallocated and remapped,
- * negative error code otherwise.
- */
-int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head)
+int __hugetlb_vmemmap_restore(const struct hstate *h, struct page *head, bool bulk)
The same as here.
{
int ret;
unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
@@ -541,7 +533,7 @@ int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head)
* When a HugeTLB page is freed to the buddy allocator, previously
* discarded vmemmap pages must be allocated and remapping.
*/
- ret = vmemmap_remap_alloc(vmemmap_start, vmemmap_end, vmemmap_reuse);
+ ret = vmemmap_remap_alloc(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk);
if (!ret) {
ClearHPageVmemmapOptimized(head);
static_branch_dec(&hugetlb_optimize_vmemmap_key);
@@ -550,12 +542,29 @@ int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head)
return ret;
}
+/**
+ * hugetlb_vmemmap_restore - restore previously optimized (by
+ * hugetlb_vmemmap_optimize()) vmemmap pages which
+ * will be reallocated and remapped.
+ * @h: struct hstate.
+ * @head: the head page whose vmemmap pages will be restored.
+ *
+ * Return: %0 if @head's vmemmap pages have been reallocated and remapped,
+ * negative error code otherwise.
+ */
+int hugetlb_vmemmap_restore(const struct hstate *h, struct page *head)
+{
+ return __hugetlb_vmemmap_restore(h, head, false);
+}
+
void hugetlb_vmemmap_restore_folios(const struct hstate *h, struct list_head *folio_list)
{
struct folio *folio;
list_for_each_entry(folio, folio_list, lru)
- hugetlb_vmemmap_restore(h, &folio->page);
+ (void)__hugetlb_vmemmap_restore(h, &folio->page, true);
Pass VMEMMAP_REMAP_BULK_PAGES directly here.
Thanks.
+
+ flush_tlb_kernel_range(0, TLB_FLUSH_ALL);
}
/* Return true iff a HugeTLB whose vmemmap should and can be optimized. */
