On 01/26/2017 01:09 PM, Michal Hocko wrote:
On Thu 12-01-17 16:37:12, Michal Hocko wrote:
[...]
+void *kvmalloc_node(size_t size, gfp_t flags, int node)
+{
+ gfp_t kmalloc_flags = flags;
+ void *ret;
+
+ /*
+ * vmalloc uses GFP_KERNEL for some internal allocations (e.g page
tables)
+ * so the given set of flags has to be compatible.
+ */
+ WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL);
+
+ /*
+ * Make sure that larger requests are not too disruptive - no OOM
+ * killer and no allocation failure warnings as we have a fallback
+ */
+ if (size > PAGE_SIZE)
+ kmalloc_flags |= __GFP_NORETRY | __GFP_NOWARN;
+
+ ret = kmalloc_node(size, kmalloc_flags, node);
+
+ /*
+ * It doesn't really make sense to fallback to vmalloc for sub page
+ * requests
+ */
+ if (ret || size <= PAGE_SIZE)
+ return ret;
+
+ return __vmalloc_node_flags(size, node, flags);
+}
+EXPORT_SYMBOL(kvmalloc_node);
While discussing bpf change I've realized that the vmalloc fallback
doesn't request __GFP_HIGHMEM. So I've updated the patch to do so. All
the current users except for f2fs_kv[zm]alloc which just seemed to
forgot or didn't know about the flag. In the next step, I would like to
check whether we actually have any __vmalloc* user which would strictly
refuse __GFP_HIGHMEM because I do not really see any reason for that and
if there is none then I would simply pull __GFP_HIGHMEM handling into
the vmalloc.
So before I resend the full series again, can I keep acks with the
following?
OK!
Thanks,
Vlastimil