On 2024/8/14 10:02, Barry Song wrote:
From: Ryan Roberts <ryan.roberts@xxxxxxx> Add thp_anon= cmdline parameter to allow specifying the default enablement of each supported anon THP size. The parameter accepts the following format and can be provided multiple times to configure each size: thp_anon=<size>,<size>[KMG]:<value>;<size>-<size>[KMG]:<value> An example: thp_anon=16K-64K:always;128K,512K:inherit;256K:madvise;1M-2M:never See Documentation/admin-guide/mm/transhuge.rst for more details. Configuring the defaults at boot time is useful to allow early user space to take advantage of mTHP before its been configured through sysfs. Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> Co-developed-by: Barry Song <v-songbaohua@xxxxxxxx> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
LGTM. Feel free to add: Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Just a small nit as below.
--- -v4: * use bitmap APIs to set and clear bits. thanks very much for David's comment! .../admin-guide/kernel-parameters.txt | 9 ++ Documentation/admin-guide/mm/transhuge.rst | 37 +++++-- mm/huge_memory.c | 96 ++++++++++++++++++- 3 files changed, 134 insertions(+), 8 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f0057bac20fb..d0d141d50638 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6629,6 +6629,15 @@ <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". + Can be used to 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 7072469de8a8..528e1a19d63f 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -284,13 +284,36 @@ 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 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 1a12c011e2df..c5f4e97b49de 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;unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,unsigned long vm_flags, @@ -737,7 +738,10 @@ 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); + anon_orders_configured = true; + }*hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);if (unlikely(!*hugepage_kobj)) { @@ -922,6 +926,96 @@ static int __init setup_transparent_hugepage(char *str) } __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); + order = fls(size >> PAGE_SHIFT) - 1;
Nit: using get_order() seems more robust?
+ if ((1 << order) & ~THP_ORDERS_ALL_ANON) {
+ pr_err("invalid size %s(order %d) in thp_anon boot parameter\n",
+ size_str, order);
+ return -EINVAL;
+ }
+
+ return order;
+}
[snip]
