diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/init-mm.c | 11 | ||||
| -rw-r--r-- | mm/memory.c | 22 |
2 files changed, 25 insertions, 8 deletions
diff --git a/mm/init-mm.c b/mm/init-mm.c index f0179c9c04c2..a787a319211e 100644 --- a/mm/init-mm.c +++ b/mm/init-mm.c @@ -15,6 +15,16 @@ #define INIT_MM_CONTEXT(name) #endif +/* + * For dynamically allocated mm_structs, there is a dynamically sized cpumask + * at the end of the structure, the size of which depends on the maximum CPU + * number the system can see. That way we allocate only as much memory for + * mm_cpumask() as needed for the hundreds, or thousands of processes that + * a system typically runs. + * + * Since there is only one init_mm in the entire system, keep it simple + * and size this cpu_bitmask to NR_CPUS. + */ struct mm_struct init_mm = { .mm_rb = RB_ROOT, .pgd = swapper_pg_dir, @@ -25,5 +35,6 @@ struct mm_struct init_mm = { .arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), .user_ns = &init_user_ns, + .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0}, INIT_MM_CONTEXT(init_mm) }; diff --git a/mm/memory.c b/mm/memory.c index c5e87a3a82ba..3d0a74ab70f2 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -326,16 +326,20 @@ bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_ #ifdef CONFIG_HAVE_RCU_TABLE_FREE -/* - * See the comment near struct mmu_table_batch. - */ - static void tlb_remove_table_smp_sync(void *arg) { - /* Simply deliver the interrupt */ + struct mm_struct __maybe_unused *mm = arg; + /* + * On most architectures this does nothing. Simply delivering the + * interrupt is enough to prevent races with software page table + * walking like that done in get_user_pages_fast. + * + * See the comment near struct mmu_table_batch. + */ + tlb_flush_remove_tables_local(mm); } -static void tlb_remove_table_one(void *table) +static void tlb_remove_table_one(void *table, struct mmu_gather *tlb) { /* * This isn't an RCU grace period and hence the page-tables cannot be @@ -344,7 +348,7 @@ static void tlb_remove_table_one(void *table) * It is however sufficient for software page-table walkers that rely on * IRQ disabling. See the comment near struct mmu_table_batch. */ - smp_call_function(tlb_remove_table_smp_sync, NULL, 1); + smp_call_function(tlb_remove_table_smp_sync, tlb->mm, 1); __tlb_remove_table(table); } @@ -365,6 +369,8 @@ void tlb_table_flush(struct mmu_gather *tlb) { struct mmu_table_batch **batch = &tlb->batch; + tlb_flush_remove_tables(tlb->mm); + if (*batch) { call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); *batch = NULL; @@ -387,7 +393,7 @@ void tlb_remove_table(struct mmu_gather *tlb, void *table) if (*batch == NULL) { *batch = (struct mmu_table_batch *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN); if (*batch == NULL) { - tlb_remove_table_one(table); + tlb_remove_table_one(table, tlb); return; } (*batch)->nr = 0; |