diff options
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 11 | ||||
| -rw-r--r-- | include/linux/huge_mm.h | 12 | ||||
| -rw-r--r-- | mm/huge_memory.c | 7 | ||||
| -rw-r--r-- | mm/khugepaged.c | 33 |
4 files changed, 38 insertions, 25 deletions
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index a1bc9b24e29a..fe237825b95c 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -202,12 +202,11 @@ PMD-mappable transparent hugepage:: cat /sys/kernel/mm/transparent_hugepage/hpage_pmd_size -khugepaged will be automatically started when one or more hugepage -sizes are enabled (either by directly setting "always" or "madvise", -or by setting "inherit" while the top-level enabled is set to "always" -or "madvise"), and it'll be automatically shutdown when the last -hugepage size is disabled (either by directly setting "never", or by -setting "inherit" while the top-level enabled is set to "never"). +khugepaged will be automatically started when PMD-sized THP is enabled +(either of the per-size anon control or the top-level control are set +to "always" or "madvise"), and it'll be automatically shutdown when +PMD-sized THP is disabled (when both the per-size anon control and the +top-level control are "never") Khugepaged controls ------------------- diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index cee3c5da8f0e..acb6ac24a07e 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -128,18 +128,6 @@ static inline bool hugepage_global_always(void) (1<<TRANSPARENT_HUGEPAGE_FLAG); } -static inline bool hugepage_flags_enabled(void) -{ - /* - * We cover both the anon and the file-backed case here; we must return - * true if globally enabled, even when all anon sizes are set to never. - * So we don't need to look at huge_anon_orders_inherit. - */ - return hugepage_global_enabled() || - READ_ONCE(huge_anon_orders_always) || - READ_ONCE(huge_anon_orders_madvise); -} - static inline int highest_order(unsigned long orders) { return fls_long(orders) - 1; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 17fb072a0ca1..f8b5cbd4dd71 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -502,6 +502,13 @@ static ssize_t thpsize_enabled_store(struct kobject *kobj, } else ret = -EINVAL; + if (ret > 0) { + int err; + + err = start_stop_khugepaged(); + if (err) + ret = err; + } return ret; } diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 409f67a817f1..a5ec03ef8722 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -413,6 +413,26 @@ static inline int hpage_collapse_test_exit_or_disable(struct mm_struct *mm) test_bit(MMF_DISABLE_THP, &mm->flags); } +static bool hugepage_pmd_enabled(void) +{ + /* + * We cover both the anon and the file-backed case here; file-backed + * hugepages, when configured in, are determined by the global control. + * Anon pmd-sized hugepages are determined by the pmd-size control. + */ + if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && + hugepage_global_enabled()) + return true; + if (test_bit(PMD_ORDER, &huge_anon_orders_always)) + return true; + if (test_bit(PMD_ORDER, &huge_anon_orders_madvise)) + return true; + if (test_bit(PMD_ORDER, &huge_anon_orders_inherit) && + hugepage_global_enabled()) + return true; + return false; +} + void __khugepaged_enter(struct mm_struct *mm) { struct khugepaged_mm_slot *mm_slot; @@ -449,7 +469,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma, unsigned long vm_flags) { if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) && - hugepage_flags_enabled()) { + hugepage_pmd_enabled()) { if (thp_vma_allowable_order(vma, vm_flags, TVA_ENFORCE_SYSFS, PMD_ORDER)) __khugepaged_enter(vma->vm_mm); @@ -2462,8 +2482,7 @@ breakouterloop_mmap_lock: static int khugepaged_has_work(void) { - return !list_empty(&khugepaged_scan.mm_head) && - hugepage_flags_enabled(); + return !list_empty(&khugepaged_scan.mm_head) && hugepage_pmd_enabled(); } static int khugepaged_wait_event(void) @@ -2536,7 +2555,7 @@ static void khugepaged_wait_work(void) return; } - if (hugepage_flags_enabled()) + if (hugepage_pmd_enabled()) wait_event_freezable(khugepaged_wait, khugepaged_wait_event()); } @@ -2567,7 +2586,7 @@ static void set_recommended_min_free_kbytes(void) int nr_zones = 0; unsigned long recommended_min; - if (!hugepage_flags_enabled()) { + if (!hugepage_pmd_enabled()) { calculate_min_free_kbytes(); goto update_wmarks; } @@ -2617,7 +2636,7 @@ int start_stop_khugepaged(void) int err = 0; mutex_lock(&khugepaged_mutex); - if (hugepage_flags_enabled()) { + if (hugepage_pmd_enabled()) { if (!khugepaged_thread) khugepaged_thread = kthread_run(khugepaged, NULL, "khugepaged"); @@ -2643,7 +2662,7 @@ fail: void khugepaged_min_free_kbytes_update(void) { mutex_lock(&khugepaged_mutex); - if (hugepage_flags_enabled() && khugepaged_thread) + if (hugepage_pmd_enabled() && khugepaged_thread) set_recommended_min_free_kbytes(); mutex_unlock(&khugepaged_mutex); } |