@@ -6926,6 +6926,13 @@
See Documentation/admin-guide/mm/transhuge.rst
for more details.
+ transparent_hugepage_shmem= [KNL]
+ Format: [always|within_size|advise|never|deny|force]
+ Can be used to control the hugepage allocation policy for
+ the internal shmem mount.
+ See Documentation/admin-guide/mm/transhuge.rst
+ for more details.
+
trusted.source= [KEYS]
Format: <string>
This parameter identifies the trust source as a backend
@@ -326,6 +326,12 @@ 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``.
+Similarly to ``transparent_hugepage``, you can control the hugepage
+allocation policy for the internal shmem mount by using the kernel parameter
+``transparent_hugepage_shmem=<policy>``, where ``<policy>`` is one of the
+seven valid policies for shmem (``always``, ``within_size``, ``advise``,
+``never``, ``deny``, and ``force``).
+
Hugepages in tmpfs/shmem
========================
@@ -582,24 +582,39 @@ static bool shmem_huge_global_enabled(struct inode *inode, pgoff_t index,
}
}
-#if defined(CONFIG_SYSFS)
static int shmem_parse_huge(const char *str)
{
+ int huge;
+
+ if (!str)
+ return -EINVAL;
+
if (!strcmp(str, "never"))
- return SHMEM_HUGE_NEVER;
- if (!strcmp(str, "always"))
- return SHMEM_HUGE_ALWAYS;
- if (!strcmp(str, "within_size"))
- return SHMEM_HUGE_WITHIN_SIZE;
- if (!strcmp(str, "advise"))
- return SHMEM_HUGE_ADVISE;
- if (!strcmp(str, "deny"))
- return SHMEM_HUGE_DENY;
- if (!strcmp(str, "force"))
- return SHMEM_HUGE_FORCE;
- return -EINVAL;
+ huge = SHMEM_HUGE_NEVER;
+ else if (!strcmp(str, "always"))
+ huge = SHMEM_HUGE_ALWAYS;
+ else if (!strcmp(str, "within_size"))
+ huge = SHMEM_HUGE_WITHIN_SIZE;
+ else if (!strcmp(str, "advise"))
+ huge = SHMEM_HUGE_ADVISE;
+ else if (!strcmp(str, "deny"))
+ huge = SHMEM_HUGE_DENY;
+ else if (!strcmp(str, "force"))
+ huge = SHMEM_HUGE_FORCE;
+ else
+ return -EINVAL;
+
+ if (!has_transparent_hugepage() &&
+ huge != SHMEM_HUGE_NEVER && huge != SHMEM_HUGE_DENY)
+ return -EINVAL;
+
+ /* Do not override huge allocation policy with non-PMD sized mTHP */
+ if (huge == SHMEM_HUGE_FORCE &&
+ huge_shmem_orders_inherit != BIT(HPAGE_PMD_ORDER))
+ return -EINVAL;
+
+ return huge;
}
-#endif
#if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS)
static const char *shmem_format_huge(int huge)
@@ -5066,15 +5081,7 @@ static ssize_t shmem_enabled_store(struct kobject *kobj,
huge = shmem_parse_huge(tmp);
if (huge == -EINVAL)
- return -EINVAL;
- if (!has_transparent_hugepage() &&
- huge != SHMEM_HUGE_NEVER && huge != SHMEM_HUGE_DENY)
- return -EINVAL;
-
- /* Do not override huge allocation policy with non-PMD sized mTHP */
- if (huge == SHMEM_HUGE_FORCE &&
- huge_shmem_orders_inherit != BIT(HPAGE_PMD_ORDER))
- return -EINVAL;
+ return huge;
shmem_huge = huge;
if (shmem_huge > SHMEM_HUGE_DENY)
@@ -5171,6 +5178,25 @@ struct kobj_attribute thpsize_shmem_enabled_attr =
__ATTR(shmem_enabled, 0644, thpsize_shmem_enabled_show, thpsize_shmem_enabled_store);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE && CONFIG_SYSFS */
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
+
+static int __init setup_transparent_hugepage_shmem(char *str)
+{
+ int huge;
+
+ huge = shmem_parse_huge(str);
+ if (huge == -EINVAL) {
+ pr_warn("transparent_hugepage_shmem= cannot parse, ignored\n");
+ return huge;
+ }
+
+ shmem_huge = huge;
+ return 1;
+}
+__setup("transparent_hugepage_shmem=", setup_transparent_hugepage_shmem);
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
#else /* !CONFIG_SHMEM */
/*
Add a new kernel command line to control the hugepage allocation policy for the internal shmem mount, ``transparent_hugepage_shmem``. The parameter is similar to ``transparent_hugepage`` and has the following format: transparent_hugepage_shmem=<policy> where ``<policy>`` is one of the seven valid policies available for shmem. By configuring the default hugepage allocation policy for the internal shmem mount, applications that use shmem, such as the DRM GEM objects, can take advantage of mTHP before it's been configured through sysfs. Signed-off-by: Maíra Canal <mcanal@igalia.com> --- .../admin-guide/kernel-parameters.txt | 7 ++ Documentation/admin-guide/mm/transhuge.rst | 6 ++ mm/shmem.c | 72 +++++++++++++------ 3 files changed, 62 insertions(+), 23 deletions(-)