mm/hugetlb.c: warn the user when issues arise on boot due to hugepages

[mirror_ubuntu-artful-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 8254e8f6db6b6c534e910770542713a8d1ccdb8c..761a669d0b62d21c7907b3f15c6dfd909674ae01 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -70,6 +70,17 @@ struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp;
 /* Forward declaration */
 static int hugetlb_acct_memory(struct hstate *h, long delta);
 
+static char * __init memfmt(char *buf, unsigned long n)
+{
+       if (n >= (1UL << 30))
+               sprintf(buf, "%lu GB", n >> 30);
+       else if (n >= (1UL << 20))
+               sprintf(buf, "%lu MB", n >> 20);
+       else
+               sprintf(buf, "%lu KB", n >> 10);
+       return buf;
+}
+
 static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
 {
        bool free = (spool->count == 0) && (spool->used_hpages == 0);
@@ -2212,7 +2223,14 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
                                         &node_states[N_MEMORY]))
                        break;
        }
-       h->max_huge_pages = i;
+       if (i < h->max_huge_pages) {
+               char buf[32];
+
+               memfmt(buf, huge_page_size(h)),
+               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;
+       }
 }
 
 static void __init hugetlb_init_hstates(void)
@@ -2230,17 +2248,6 @@ static void __init hugetlb_init_hstates(void)
        VM_BUG_ON(minimum_order == UINT_MAX);
 }
 
-static char * __init memfmt(char *buf, unsigned long n)
-{
-       if (n >= (1UL << 30))
-               sprintf(buf, "%lu GB", n >> 30);
-       else if (n >= (1UL << 20))
-               sprintf(buf, "%lu MB", n >> 20);
-       else
-               sprintf(buf, "%lu KB", n >> 10);
-       return buf;
-}
-
 static void __init report_hugepages(void)
 {
        struct hstate *h;
@@ -2808,6 +2815,11 @@ static int __init hugetlb_init(void)
                return 0;
 
        if (!size_to_hstate(default_hstate_size)) {
+               if (default_hstate_size != 0) {
+                       pr_err("HugeTLB: unsupported default_hugepagesz %lu. Reverting to %lu\n",
+                              default_hstate_size, HPAGE_SIZE);
+               }
+
                default_hstate_size = HPAGE_SIZE;
                if (!size_to_hstate(default_hstate_size))
                        hugetlb_add_hstate(HUGETLB_PAGE_ORDER);