diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 38 | ||||
| -rw-r--r-- | mm/huge_memory.c | 98 |
3 files changed, 137 insertions, 8 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 09126bb8cc9f..998076fd4882 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6614,6 +6614,15 @@ <deci-seconds>: poll all this frequency 0: no polling (default) + thp_anon= [KNL] + Format: <size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state> + state is one of "always", "madvise", "never" or "inherit". + Control the default behavior of the system with respect + to anonymous transparent hugepages. + Can be used multiple times for multiple anon THP sizes. + See Documentation/admin-guide/mm/transhuge.rst for more + details. + threadirqs [KNL,EARLY] Force threading of all interrupt handlers except those marked explicitly IRQF_NO_THREAD. diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 058485daf186..79435c537e21 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -284,13 +284,37 @@ that THP is shared. Exceeding the number would block the collapse:: A higher value may increase memory footprint for some workloads. -Boot parameter -============== - -You can change the sysfs boot time defaults of Transparent Hugepage -Support by passing the parameter ``transparent_hugepage=always`` or -``transparent_hugepage=madvise`` or ``transparent_hugepage=never`` -to the kernel command line. +Boot parameters +=============== + +You can change the sysfs boot time default for the top-level "enabled" +control by passing the parameter ``transparent_hugepage=always`` or +``transparent_hugepage=madvise`` or ``transparent_hugepage=never`` to the +kernel command line. + +Alternatively, each supported anonymous THP size can be controlled by +passing ``thp_anon=<size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>``, +where ``<size>`` is the THP size (must be a power of 2 of PAGE_SIZE and +supported anonymous THP) and ``<state>`` is one of ``always``, ``madvise``, +``never`` or ``inherit``. + +For example, the following will set 16K, 32K, 64K THP to ``always``, +set 128K, 512K to ``inherit``, set 256K to ``madvise`` and 1M, 2M +to ``never``:: + + thp_anon=16K-64K:always;128K,512K:inherit;256K:madvise;1M-2M:never + +``thp_anon=`` may be specified multiple times to configure all THP sizes as +required. If ``thp_anon=`` is specified at least once, any anon THP sizes +not explicitly configured on the command line are implicitly set to +``never``. + +``transparent_hugepage`` setting only affects the global toggle. If +``thp_anon`` is not specified, PMD_ORDER THP will default to ``inherit``. +However, if a valid ``thp_anon`` setting is provided by the user, the +PMD_ORDER THP policy will be overridden. If the policy for PMD_ORDER +is not defined within a valid ``thp_anon``, its policy will default to +``never``. Hugepages in tmpfs/shmem ======================== diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ac9e8a77059d..ef6d4f617c4a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -81,6 +81,7 @@ unsigned long huge_zero_pfn __read_mostly = ~0UL; unsigned long huge_anon_orders_always __read_mostly; unsigned long huge_anon_orders_madvise __read_mostly; unsigned long huge_anon_orders_inherit __read_mostly; +static bool anon_orders_configured __initdata; unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, unsigned long vm_flags, @@ -649,7 +650,8 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) * disable all other sizes. powerpc's PMD_ORDER isn't a compile-time * constant so we have to do this here. */ - huge_anon_orders_inherit = BIT(PMD_ORDER); + if (!anon_orders_configured) + huge_anon_orders_inherit = BIT(PMD_ORDER); *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj); if (unlikely(!*hugepage_kobj)) { @@ -834,6 +836,100 @@ out: } __setup("transparent_hugepage=", setup_transparent_hugepage); +static inline int get_order_from_str(const char *size_str) +{ + unsigned long size; + char *endptr; + int order; + + size = memparse(size_str, &endptr); + + if (!is_power_of_2(size)) + goto err; + order = get_order(size); + if (BIT(order) & ~THP_ORDERS_ALL_ANON) + goto err; + + return order; +err: + pr_err("invalid size %s in thp_anon boot parameter\n", size_str); + return -EINVAL; +} + +static char str_dup[PAGE_SIZE] __initdata; +static int __init setup_thp_anon(char *str) +{ + char *token, *range, *policy, *subtoken; + unsigned long always, inherit, madvise; + char *start_size, *end_size; + int start, end, nr; + char *p; + + if (!str || strlen(str) + 1 > PAGE_SIZE) + goto err; + strcpy(str_dup, str); + + always = huge_anon_orders_always; + madvise = huge_anon_orders_madvise; + inherit = huge_anon_orders_inherit; + p = str_dup; + while ((token = strsep(&p, ";")) != NULL) { + range = strsep(&token, ":"); + policy = token; + + if (!policy) + goto err; + + while ((subtoken = strsep(&range, ",")) != NULL) { + if (strchr(subtoken, '-')) { + start_size = strsep(&subtoken, "-"); + end_size = subtoken; + + start = get_order_from_str(start_size); + end = get_order_from_str(end_size); + } else { + start = end = get_order_from_str(subtoken); + } + + if (start < 0 || end < 0 || start > end) + goto err; + + nr = end - start + 1; + if (!strcmp(policy, "always")) { + bitmap_set(&always, start, nr); + bitmap_clear(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + } else if (!strcmp(policy, "madvise")) { + bitmap_set(&madvise, start, nr); + bitmap_clear(&inherit, start, nr); + bitmap_clear(&always, start, nr); + } else if (!strcmp(policy, "inherit")) { + bitmap_set(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&always, start, nr); + } else if (!strcmp(policy, "never")) { + bitmap_clear(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&always, start, nr); + } else { + pr_err("invalid policy %s in thp_anon boot parameter\n", policy); + goto err; + } + } + } + + huge_anon_orders_always = always; + huge_anon_orders_madvise = madvise; + huge_anon_orders_inherit = inherit; + anon_orders_configured = true; + return 1; + +err: + pr_warn("thp_anon=%s: error parsing string, ignoring setting\n", str); + return 0; +} +__setup("thp_anon=", setup_thp_anon); + pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) |