Merge tag 'x86-mm-2025-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 mm updates from Ingo Molnar:

 - The biggest changes are the TLB flushing scalability optimizations,
   to update the mm_cpumask lazily and related changes.

   This feature has both a track record and a continued risk of
   performance regressions, so it was already delayed by a cycle - but
   it's all 100% perfect now™ (Rik van Riel)

 - Also miscellaneous fixes and cleanups. (Gautam Somani, Kirill
   Shutemov, Sebastian Andrzej Siewior)

* tag 'x86-mm-2025-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Remove unnecessary include of <linux/extable.h>
  x86/mtrr: Rename mtrr_overwrite_state() to guest_force_mtrr_state()
  x86/mm/selftests: Fix typo in lam.c
  x86/mm/tlb: Only trim the mm_cpumask once a second
  x86/mm/tlb: Also remove local CPU from mm_cpumask if stale
  x86/mm/tlb: Add tracepoint for TLB flush IPI to stale CPU
  x86/mm/tlb: Update mm_cpumask lazily

1 files changed, 7 insertions, 3 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 243843e44e89..c71b575bf229 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1854,11 +1854,18 @@ static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm)
 	return temp_state;
 }
 
+__ro_after_init struct mm_struct *poking_mm;
+__ro_after_init unsigned long poking_addr;
+
 static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
 {
 	lockdep_assert_irqs_disabled();
+
 	switch_mm_irqs_off(NULL, prev_state.mm, current);
 
+	/* Clear the cpumask, to indicate no TLB flushing is needed anywhere */
+	cpumask_clear_cpu(raw_smp_processor_id(), mm_cpumask(poking_mm));
+
 	/*
 	 * Restore the breakpoints if they were disabled before the temporary mm
 	 * was loaded.
@@ -1867,9 +1874,6 @@ static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
 		hw_breakpoint_restore();
 }
 
-__ro_after_init struct mm_struct *poking_mm;
-__ro_after_init unsigned long poking_addr;
-
 static void text_poke_memcpy(void *dst, const void *src, size_t len)
 {
 	memcpy(dst, src, len);