From 7ca02d0ae586fe7df59632966a64f3f1a756ef05 Mon Sep 17 00:00:00 2001 From: Mike Kravetz Date: Wed, 15 Apr 2015 16:13:42 -0700 Subject: hugetlbfs: accept subpool min_size mount option and setup accordingly Make 'min_size=' be an option when mounting a hugetlbfs. This option takes the same value as the 'size' option. min_size can be specified without specifying size. If both are specified, min_size must be less that or equal to size else the mount will fail. If min_size is specified, then at mount time an attempt is made to reserve min_size pages. If the reservation fails, the mount fails. At umount time, the reserved pages are released. Signed-off-by: Mike Kravetz Cc: Davidlohr Bueso Cc: Aneesh Kumar Cc: Joonsoo Kim Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 90 ++++++++++++++++++++++++++++++++++++++----------- include/linux/hugetlb.h | 3 +- mm/hugetlb.c | 25 +++++++++++--- 3 files changed, 94 insertions(+), 24 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index db76cec..3a8f127 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -47,9 +47,10 @@ struct hugetlbfs_config { kuid_t uid; kgid_t gid; umode_t mode; - long nr_blocks; + long max_hpages; long nr_inodes; struct hstate *hstate; + long min_hpages; }; struct hugetlbfs_inode_info { @@ -67,7 +68,7 @@ int sysctl_hugetlb_shm_group; enum { Opt_size, Opt_nr_inodes, Opt_mode, Opt_uid, Opt_gid, - Opt_pagesize, + Opt_pagesize, Opt_min_size, Opt_err, }; @@ -78,6 +79,7 @@ static const match_table_t tokens = { {Opt_uid, "uid=%u"}, {Opt_gid, "gid=%u"}, {Opt_pagesize, "pagesize=%s"}, + {Opt_min_size, "min_size=%s"}, {Opt_err, NULL}, }; @@ -754,14 +756,38 @@ static const struct super_operations hugetlbfs_ops = { .show_options = generic_show_options, }; +enum { NO_SIZE, SIZE_STD, SIZE_PERCENT }; + +/* + * Convert size option passed from command line to number of huge pages + * in the pool specified by hstate. Size option could be in bytes + * (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT). + */ +static long long +hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt, + int val_type) +{ + if (val_type == NO_SIZE) + return -1; + + if (val_type == SIZE_PERCENT) { + size_opt <<= huge_page_shift(h); + size_opt *= h->max_huge_pages; + do_div(size_opt, 100); + } + + size_opt >>= huge_page_shift(h); + return size_opt; +} + static int hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) { char *p, *rest; substring_t args[MAX_OPT_ARGS]; int option; - unsigned long long size = 0; - enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE; + unsigned long long max_size_opt = 0, min_size_opt = 0; + int max_val_type = NO_SIZE, min_val_type = NO_SIZE; if (!options) return 0; @@ -799,10 +825,10 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) /* memparse() will accept a K/M/G without a digit */ if (!isdigit(*args[0].from)) goto bad_val; - size = memparse(args[0].from, &rest); - setsize = SIZE_STD; + max_size_opt = memparse(args[0].from, &rest); + max_val_type = SIZE_STD; if (*rest == '%') - setsize = SIZE_PERCENT; + max_val_type = SIZE_PERCENT; break; } @@ -825,6 +851,17 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) break; } + case Opt_min_size: { + /* memparse() will accept a K/M/G without a digit */ + if (!isdigit(*args[0].from)) + goto bad_val; + min_size_opt = memparse(args[0].from, &rest); + min_val_type = SIZE_STD; + if (*rest == '%') + min_val_type = SIZE_PERCENT; + break; + } + default: pr_err("Bad mount option: \"%s\"\n", p); return -EINVAL; @@ -832,15 +869,22 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) } } - /* Do size after hstate is set up */ - if (setsize > NO_SIZE) { - struct hstate *h = pconfig->hstate; - if (setsize == SIZE_PERCENT) { - size <<= huge_page_shift(h); - size *= h->max_huge_pages; - do_div(size, 100); - } - pconfig->nr_blocks = (size >> huge_page_shift(h)); + /* + * Use huge page pool size (in hstate) to convert the size + * options to number of huge pages. If NO_SIZE, -1 is returned. + */ + pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate, + max_size_opt, max_val_type); + pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate, + min_size_opt, min_val_type); + + /* + * If max_size was specified, then min_size must be smaller + */ + if (max_val_type > NO_SIZE && + pconfig->min_hpages > pconfig->max_hpages) { + pr_err("minimum size can not be greater than maximum size\n"); + return -EINVAL; } return 0; @@ -859,12 +903,13 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) save_mount_options(sb, data); - config.nr_blocks = -1; /* No limit on size by default */ + config.max_hpages = -1; /* No limit on size by default */ config.nr_inodes = -1; /* No limit on number of inodes by default */ config.uid = current_fsuid(); config.gid = current_fsgid(); config.mode = 0755; config.hstate = &default_hstate; + config.min_hpages = -1; /* No default minimum size */ ret = hugetlbfs_parse_options(data, &config); if (ret) return ret; @@ -878,8 +923,15 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) sbinfo->max_inodes = config.nr_inodes; sbinfo->free_inodes = config.nr_inodes; sbinfo->spool = NULL; - if (config.nr_blocks != -1) { - sbinfo->spool = hugepage_new_subpool(config.nr_blocks); + /* + * Allocate and initialize subpool if maximum or minimum size is + * specified. Any needed reservations (for minimim size) are taken + * taken when the subpool is created. + */ + if (config.max_hpages != -1 || config.min_hpages != -1) { + sbinfo->spool = hugepage_new_subpool(config.hstate, + config.max_hpages, + config.min_hpages); if (!sbinfo->spool) goto out_free; } diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index d1a77b8..5713c49 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -44,7 +44,8 @@ extern int hugetlb_max_hstate __read_mostly; #define for_each_hstate(h) \ for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++) -struct hugepage_subpool *hugepage_new_subpool(long nr_blocks); +struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, + long min_hpages); void hugepage_put_subpool(struct hugepage_subpool *spool); void reset_vma_resv_huge_pages(struct vm_area_struct *vma); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 499cb72..995c8d6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -61,6 +61,9 @@ 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); @@ -68,12 +71,18 @@ static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) spin_unlock(&spool->lock); /* If no pages are used, and no other handles to the subpool - * remain, free the subpool the subpool remain */ - if (free) + * remain, give up any reservations mased on minimum size and + * free the subpool */ + if (free) { + if (spool->min_hpages != -1) + hugetlb_acct_memory(spool->hstate, + -spool->min_hpages); kfree(spool); + } } -struct hugepage_subpool *hugepage_new_subpool(long nr_blocks) +struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, + long min_hpages) { struct hugepage_subpool *spool; @@ -83,7 +92,15 @@ struct hugepage_subpool *hugepage_new_subpool(long nr_blocks) spin_lock_init(&spool->lock); spool->count = 1; - spool->max_hpages = nr_blocks; + spool->max_hpages = max_hpages; + spool->hstate = h; + spool->min_hpages = min_hpages; + + if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) { + kfree(spool); + return NULL; + } + spool->rsv_hpages = min_hpages; return spool; } -- cgit v1.1