Functionally, no change. This is a preparation for migrc mechanism that requires to recognize read-only TLB entries and makes use of them to batch more aggressively. Plus, the newly introduced API, fold_ubc() will be used by migrc mechanism when manipulating tlb batch data. Signed-off-by: Byungchul Park <byungchul@xxxxxx> --- include/linux/sched.h | 1 + mm/internal.h | 4 ++++ mm/rmap.c | 31 ++++++++++++++++++++++++++++++- 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 292c31697248..0317e7a65151 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1328,6 +1328,7 @@ struct task_struct { #endif struct tlbflush_unmap_batch tlb_ubc; + struct tlbflush_unmap_batch tlb_ubc_ro; /* Cache last used pipe for splice(): */ struct pipe_inode_info *splice_pipe; diff --git a/mm/internal.h b/mm/internal.h index b61034bd50f5..b880f1e78700 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -923,6 +923,7 @@ extern struct workqueue_struct *mm_percpu_wq; void try_to_unmap_flush(void); void try_to_unmap_flush_dirty(void); void flush_tlb_batched_pending(struct mm_struct *mm); +void fold_ubc(struct tlbflush_unmap_batch *dst, struct tlbflush_unmap_batch *src); #else static inline void try_to_unmap_flush(void) { @@ -933,6 +934,9 @@ static inline void try_to_unmap_flush_dirty(void) static inline void flush_tlb_batched_pending(struct mm_struct *mm) { } +static inline void fold_ubc(struct tlbflush_unmap_batch *dst, struct tlbflush_unmap_batch *src) +{ +} #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */ extern const struct trace_print_flags pageflag_names[]; diff --git a/mm/rmap.c b/mm/rmap.c index 7a27a2b41802..da36f23ff7b0 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -605,6 +605,28 @@ struct anon_vma *folio_lock_anon_vma_read(struct folio *folio, } #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH + +void fold_ubc(struct tlbflush_unmap_batch *dst, + struct tlbflush_unmap_batch *src) +{ + if (!src->flush_required) + return; + + /* + * Fold src to dst. + */ + arch_tlbbatch_fold(&dst->arch, &src->arch); + dst->writable = dst->writable || src->writable; + dst->flush_required = true; + + /* + * Reset src. + */ + arch_tlbbatch_clear(&src->arch); + src->flush_required = false; + src->writable = false; +} + /* * Flush TLB entries for recently unmapped pages from remote CPUs. It is * important if a PTE was dirty when it was unmapped that it's flushed @@ -614,7 +636,9 @@ struct anon_vma *folio_lock_anon_vma_read(struct folio *folio, void try_to_unmap_flush(void) { struct tlbflush_unmap_batch *tlb_ubc = ¤t->tlb_ubc; + struct tlbflush_unmap_batch *tlb_ubc_ro = ¤t->tlb_ubc_ro; + fold_ubc(tlb_ubc, tlb_ubc_ro); if (!tlb_ubc->flush_required) return; @@ -645,13 +669,18 @@ void try_to_unmap_flush_dirty(void) static void set_tlb_ubc_flush_pending(struct mm_struct *mm, pte_t pteval, unsigned long uaddr) { - struct tlbflush_unmap_batch *tlb_ubc = ¤t->tlb_ubc; + struct tlbflush_unmap_batch *tlb_ubc; int batch; bool writable = pte_dirty(pteval); if (!pte_accessible(mm, pteval)) return; + if (pte_write(pteval) || writable) + tlb_ubc = ¤t->tlb_ubc; + else + tlb_ubc = ¤t->tlb_ubc_ro; + arch_tlbbatch_add_pending(&tlb_ubc->arch, mm, uaddr); tlb_ubc->flush_required = true; -- 2.17.1