Presently, the sole use case of hstate::max_huge_pages is confined to
hugetlb_sysctl_handler_common() and hugetlbfs_size_to_hpages().
The former has been replaced with hstate::nr_huge_pages, while the latter
can be effortlessly substituted.
After hugeltb subsystem has been initialized, hstate::max_huge_pages
always equals to persistent_huge_pages(). It's a burden to maintain
the equation[1][2].
After this patch, hstate::max_huge_pages is only used in kernel command
line parameter parsing.
Renaming set_max_huge_pages() to set_nr_huge_pages() would enhance the
readability of the code.
[1]: Commit a43a83c79b4f ("mm/hugetlb: fix incorrect update of
max_huge_pages")
[2]: Commit c1470b33bb6e ("mm/hugetlb: fix incorrect hugepages count
during mem hotplug")
Signed-off-by: Xueshi Hu <xueshi.hu@xxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 2 +-
mm/hugetlb.c | 24 +++++-------------------
2 files changed, 6 insertions(+), 20 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 316c4cebd3f3..cd1a3e4bf8fb 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1375,7 +1375,7 @@ hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
if (val_type == SIZE_PERCENT) {
size_opt <<= huge_page_shift(h);
- size_opt *= h->max_huge_pages;
+ size_opt *= (h->nr_huge_pages - h->surplus_huge_pages);
do_div(size_opt, 100);
}
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 76af189053f0..56647235ab21 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2343,14 +2343,13 @@ int dissolve_free_huge_page(struct page *page)
}
remove_hugetlb_folio(h, folio, false);
- h->max_huge_pages--;
spin_unlock_irq(&hugetlb_lock);
/*
* Normally update_and_free_hugtlb_folio will allocate required vmemmmap
* before freeing the page. update_and_free_hugtlb_folio will fail to
* free the page if it can not allocate required vmemmap. We
- * need to adjust max_huge_pages if the page is not freed.
+ * need to adjust nr_huge_pages if the page is not freed.
* Attempt to allocate vmemmmap here so that we can take
* appropriate action on failure.
*/
@@ -2360,7 +2359,6 @@ int dissolve_free_huge_page(struct page *page)
} else {
spin_lock_irq(&hugetlb_lock);
add_hugetlb_folio(h, folio, false);
- h->max_huge_pages++;
spin_unlock_irq(&hugetlb_lock);
}
@@ -3274,8 +3272,6 @@ static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n",
h->max_huge_pages_node[nid], buf, nid, i);
- h->max_huge_pages -= (h->max_huge_pages_node[nid] - i);
- h->max_huge_pages_node[nid] = i;
}
static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
@@ -3336,7 +3332,6 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n",
h->max_huge_pages, buf, i);
- h->max_huge_pages = i;
}
kfree(node_alloc_noretry);
}
@@ -3460,7 +3455,7 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
}
#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
-static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
+static int set_nr_huge_pages(struct hstate *h, unsigned long count, int nid,
nodemask_t *nodes_allowed)
{
unsigned long min_count, ret;
@@ -3601,7 +3596,6 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
break;
}
out:
- h->max_huge_pages = persistent_huge_pages(h);
spin_unlock_irq(&hugetlb_lock);
mutex_unlock(&h->resize_lock);
@@ -3639,7 +3633,7 @@ static int demote_free_hugetlb_folio(struct hstate *h, struct folio *folio)
destroy_compound_hugetlb_folio_for_demote(folio, huge_page_order(h));
/*
- * Taking target hstate mutex synchronizes with set_max_huge_pages.
+ * Taking target hstate mutex synchronizes with set_nr_huge_pages.
* Without the mutex, pages added to target hstate could be marked
* as surplus.
*
@@ -3664,14 +3658,6 @@ static int demote_free_hugetlb_folio(struct hstate *h, struct folio *folio)
spin_lock_irq(&hugetlb_lock);
- /*
- * Not absolutely necessary, but for consistency update max_huge_pages
- * based on pool changes for the demoted page.
- */
- h->max_huge_pages--;
- target_hstate->max_huge_pages +=
- pages_per_huge_page(h) / pages_per_huge_page(target_hstate);
-
return rc;
}
@@ -3770,13 +3756,13 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
} else {
/*
* Node specific request. count adjustment happens in
- * set_max_huge_pages() after acquiring hugetlb_lock.
+ * set_nr_huge_pages() after acquiring hugetlb_lock.
*/
init_nodemask_of_node(&nodes_allowed, nid);
n_mask = &nodes_allowed;
}
- err = set_max_huge_pages(h, count, nid, n_mask);
+ err = set_nr_huge_pages(h, count, nid, n_mask);
return err ? err : len;
}
--
2.40.1
