On Tue, 26 Feb 2019, Jing Xiangfeng wrote: > On 2019/2/26 3:17, David Rientjes wrote: > > On Mon, 25 Feb 2019, Mike Kravetz wrote: > > > >> Ok, what about just moving the calculation/check inside the lock as in the > >> untested patch below? > >> > >> Signed-off-by: Mike Kravetz <[email protected]> > >> --- > >> mm/hugetlb.c | 34 ++++++++++++++++++++++++++-------- > >> 1 file changed, 26 insertions(+), 8 deletions(-) > >> > >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c > >> index 1c5219193b9e..5afa77dc7bc8 100644 > >> --- a/mm/hugetlb.c > >> +++ b/mm/hugetlb.c > >> @@ -2274,7 +2274,7 @@ 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, > >> +static int set_max_huge_pages(struct hstate *h, unsigned long count, int > >> nid, > >> nodemask_t *nodes_allowed) > >> { > >> unsigned long min_count, ret; > >> @@ -2289,6 +2289,23 @@ static int set_max_huge_pages(struct hstate *h, > >> unsigned > >> long count, > >> goto decrease_pool; > >> } > >> > >> + spin_lock(&hugetlb_lock); > >> + > >> + /* > >> + * Check for a node specific request. Adjust global count, but > >> + * restrict alloc/free to the specified node. > >> + */ > >> + if (nid != NUMA_NO_NODE) { > >> + unsigned long old_count = count; > >> + count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; > >> + /* > >> + * If user specified count causes overflow, set to > >> + * largest possible value. > >> + */ > >> + if (count < old_count) > >> + count = ULONG_MAX; > >> + } > >> + > >> /* > >> * Increase the pool size > >> * First take pages out of surplus state. Then make up the > >> @@ -2300,7 +2317,6 @@ static int set_max_huge_pages(struct hstate *h, > >> unsigned > >> long count, > >> * pool might be one hugepage larger than it needs to be, but > >> * within all the constraints specified by the sysctls. > >> */ > >> - spin_lock(&hugetlb_lock); > >> while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { > >> if (!adjust_pool_surplus(h, nodes_allowed, -1)) > >> break; > >> @@ -2421,16 +2437,18 @@ static ssize_t __nr_hugepages_store_common(bool > >> obey_mempolicy, > >> nodes_allowed = &node_states[N_MEMORY]; > >> } > >> } else if (nodes_allowed) { > >> + /* Node specific request */ > >> + init_nodemask_of_node(nodes_allowed, nid); > >> + } else { > >> /* > >> - * per node hstate attribute: adjust count to global, > >> - * but restrict alloc/free to the specified node. > >> + * Node specific request, but we could not allocate > >> + * node mask. Pass in ALL nodes, and clear nid. > >> */ > >> - count += h->nr_huge_pages - h->nr_huge_pages_node[nid]; > >> - init_nodemask_of_node(nodes_allowed, nid); > >> - } else > >> + nid = NUMA_NO_NODE; > >> nodes_allowed = &node_states[N_MEMORY]; > >> + } > >> > >> - err = set_max_huge_pages(h, count, nodes_allowed); > >> + err = set_max_huge_pages(h, count, nid, nodes_allowed); > >> if (err) > >> goto out; > >> > > > > Looks good; Jing, could you test that this fixes your case? > > Yes, I have tested this patch, it can also fix my case.
Great! Reported-by: Jing Xiangfeng <[email protected]> Tested-by: Jing Xiangfeng <[email protected]> Acked-by: David Rientjes <[email protected]>
