On 17.08.24 06:55, 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>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Lance Yang <ioworker0@xxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Some nits:
---
-v5:
* collect Baolin's reviewed-by and tested-by tags, thanks!
* use get_order and check size is power 2, David, Baolin;
* use proper __initdata
.../admin-guide/kernel-parameters.txt | 9 ++
Documentation/admin-guide/mm/transhuge.rst | 38 +++++--
mm/huge_memory.c | 100 +++++++++++++++++-
3 files changed, 139 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
s/Can be used to control/Control/
+ 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 60522f49178b..4468851b6ecb 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.
[...]
unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
unsigned long vm_flags,
@@ -756,7 +757,10 @@ 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)) {
@@ -941,6 +945,100 @@ 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);
+
+ if (!is_power_of_2(size))
+ goto err;
+ order = get_order(size);
+ if ((1 << order) & ~THP_ORDERS_ALL_ANON)
Could do
"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;
Should we only pickup these values if "anon_orders_configured",
otherwise start with 0? Likely that's implicit right now.
+ 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;
This only works as long as we don't have any "Holes", which is the case
right now.
+ 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: cannot parse, ignored\n", str);
"cannot parse, ignored" -> "error parsing string, ignoring setting" ?
+ 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))
--
Cheers,
David / dhildenb
