Make reserved be an option when mounting a hugetlbfs. reserved
option is only possible if size option is also specified. On mount,
reserve size hugepages and note in subpool. Unreserve pages when
fs is unmounted.
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 15 +++++++++++++--
include/linux/hugetlb.h | 1 +
mm/hugetlb.c | 15 ++++++++++++++-
3 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 5eba47f..99d0cec 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -50,6 +50,7 @@ struct hugetlbfs_config {
long nr_blocks;
long nr_inodes;
struct hstate *hstate;
+ bool reserved;
};
struct hugetlbfs_inode_info {
@@ -73,7 +74,7 @@ int sysctl_hugetlb_shm_group;
enum {
Opt_size, Opt_nr_inodes,
Opt_mode, Opt_uid, Opt_gid,
- Opt_pagesize,
+ Opt_pagesize, Opt_reserved,
Opt_err,
};
@@ -84,6 +85,7 @@ static const match_table_t tokens = {
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_pagesize, "pagesize=%s"},
+ {Opt_reserved, "reserved"},
{Opt_err, NULL},
};
@@ -832,6 +834,10 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
break;
}
+ case Opt_reserved:
+ pconfig->reserved = true;
+ break;
+
default:
pr_err("Bad mount option: \"%s\"\n", p);
return -EINVAL;
@@ -872,6 +878,7 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
config.gid = current_fsgid();
config.mode = 0755;
config.hstate = &default_hstate;
+ config.reserved = false;
ret = hugetlbfs_parse_options(data, &config);
if (ret)
return ret;
@@ -889,7 +896,11 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
sbinfo->spool = hugepage_new_subpool(config.nr_blocks);
if (!sbinfo->spool)
goto out_free;
- }
+ sbinfo->spool->hstate = config.hstate;
+ if (config.reserved && !reserve_hugepage_subpool(sbinfo->spool))
+ goto out_free;
+ } else if (config.reserved)
+ goto out_free;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = huge_page_size(config.hstate);
sb->s_blocksize_bits = huge_page_shift(config.hstate);
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 605c648..117e1bd 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -45,6 +45,7 @@ static inline bool subpool_reserved(struct hugepage_subpool *spool)
return spool && spool->reserved;
}
struct hugepage_subpool *hugepage_new_subpool(long nr_blocks);
+bool reserve_hugepage_subpool(struct hugepage_subpool *spool);
void hugepage_put_subpool(struct hugepage_subpool *spool);
int PageHuge(struct page *page);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4ef8379..3ae3596 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -61,6 +61,8 @@ DEFINE_SPINLOCK(hugetlb_lock);
static int num_fault_mutexes;
static struct mutex *htlb_fault_mutex_table ____cacheline_aligned_in_smp;
+/* Forward declaration */
+static int hugetlb_acct_memory(struct hstate *h, long delta);
static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
{
bool free = (spool->count == 0) && (spool->used_hpages == 0);
@@ -69,8 +71,11 @@ static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
/* If no pages are used, and no other handles to the subpool
* remain, free the subpool the subpool remain */
- if (free)
+ if (free) {
+ if (spool->reserved)
+ hugetlb_acct_memory(spool->hstate, -spool->max_hpages);
kfree(spool);
+ }
}
struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
@@ -91,6 +96,14 @@ struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
return spool;
}
+bool reserve_hugepage_subpool(struct hugepage_subpool *spool)
+{
+ if (hugetlb_acct_memory(spool->hstate, spool->max_hpages))
+ return false;
+ spool->reserved = true;
+ return true;
+}
+
void hugepage_put_subpool(struct hugepage_subpool *spool)
{
spin_lock(&spool->lock);
--
2.1.0
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