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| author | Usama Arif <usamaarif642@gmail.com> | 2024-08-30 11:03:40 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-09 16:39:04 -0700 |
| commit | 81d3ff3c6f76306b22138d69e980634f53bf17fa (patch) | |
| tree | 18bd4eb7cddb4ebb08321191a03b009f424504e5 /mm/huge_memory.c | |
| parent | dafff3f4c850c98e15501bc6ee20581f9a013dcc (diff) | |
| download | linux-81d3ff3c6f76306b22138d69e980634f53bf17fa.tar.gz linux-81d3ff3c6f76306b22138d69e980634f53bf17fa.tar.bz2 linux-81d3ff3c6f76306b22138d69e980634f53bf17fa.zip | |
mm: add sysfs entry to disable splitting underused THPs
If disabled, THPs faulted in or collapsed will not be added to
_deferred_list, and therefore won't be considered for splitting under
memory pressure if underused.
Link: https://lkml.kernel.org/r/20240830100438.3623486-7-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Cc: Alexander Zhu <alexlzhu@fb.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuang Zhai <zhais@google.com>
Cc: Shuang Zhai <szhai2@cs.rochester.edu>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cec5bce046a0..691702e39f85 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -74,6 +74,7 @@ static unsigned long deferred_split_count(struct shrinker *shrink, struct shrink_control *sc); static unsigned long deferred_split_scan(struct shrinker *shrink, struct shrink_control *sc); +static bool split_underused_thp = true; static atomic_t huge_zero_refcount; struct folio *huge_zero_folio __read_mostly; @@ -440,6 +441,27 @@ static ssize_t hpage_pmd_size_show(struct kobject *kobj, static struct kobj_attribute hpage_pmd_size_attr = __ATTR_RO(hpage_pmd_size); +static ssize_t split_underused_thp_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%d\n", split_underused_thp); +} + +static ssize_t split_underused_thp_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int err = kstrtobool(buf, &split_underused_thp); + + if (err < 0) + return err; + + return count; +} + +static struct kobj_attribute split_underused_thp_attr = __ATTR( + shrink_underused, 0644, split_underused_thp_show, split_underused_thp_store); + static struct attribute *hugepage_attr[] = { &enabled_attr.attr, &defrag_attr.attr, @@ -448,6 +470,7 @@ static struct attribute *hugepage_attr[] = { #ifdef CONFIG_SHMEM &shmem_enabled_attr.attr, #endif + &split_underused_thp_attr.attr, NULL, }; @@ -3557,6 +3580,9 @@ void deferred_split_folio(struct folio *folio, bool partially_mapped) if (folio_order(folio) <= 1) return; + if (!partially_mapped && !split_underused_thp) + return; + /* * The try_to_unmap() in page reclaim path might reach here too, * this may cause a race condition to corrupt deferred split queue. |