On Wed, 2023-06-21 at 11:02 -0700, Nadav Amit wrote:

quoted

On Jun 20, 2023, at 7:46 AM, Yair Podemsky [off-list ref]
wrote:

@@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct

mm_struct *mm, struct vm_area_struct *v
				addr + HPAGE_PMD_SIZE);
	mmu_notifier_invalidate_range_start(&range);
	pmd = pmdp_collapse_flush(vma, addr, pmdp);
-	tlb_remove_table_sync_one();
+	tlb_remove_table_sync_one(mm);

Can’t pmdp_collapse_flush() have one additional argument
“freed_tables”
that it would propagate, for instance on x86 to flush_tlb_mm_range()
?
Then you would not need tlb_remove_table_sync_one() to issue an
additional
IPI, no?

It just seems that you might still have 2 IPIs in many cases instead
of
one, and unless I am missing something, I don’t see why.

Hi Nadav,
Thanks for your comment.
I think you are right and in some configurations 2 IPIs might occur.
However I a am not really dealing with the thp code at the moment,
This patch is about the mmu_gatherer and mostly dealing with IPIs sent
via the other code path.
Thanks,
Yair