X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=wrapper%2Fvmalloc.h;h=e117584f37b6ae66a7ccae65dced8c061444d58e;hb=ecda9325cd5ad6b69600fd4d88c46095d22f95e1;hp=dad8d4e34498426762a1d195ed0510f47248c26a;hpb=5a2f5e92e422d87a28581ba97e6b1789ff743bc6;p=lttng-modules.git

diff --git a/wrapper/vmalloc.h b/wrapper/vmalloc.h
index dad8d4e3..e117584f 100644
--- a/wrapper/vmalloc.h
+++ b/wrapper/vmalloc.h
@@ -25,6 +25,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <linux/version.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
 #ifdef CONFIG_KALLSYMS
 
 #include <linux/kallsyms.h>
@@ -44,15 +48,13 @@ void wrapper_vmalloc_sync_all(void)
 		 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
 		 * trigger recursive page faults.
 		 */
-		printk(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
-		printk(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
+		printk_once(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
+		printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
 #endif
 	}
 }
 #else
 
-#include <linux/vmalloc.h>
-
 static inline
 void wrapper_vmalloc_sync_all(void)
 {
@@ -60,4 +62,167 @@ void wrapper_vmalloc_sync_all(void)
 }
 #endif
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
+static inline
+void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
+{
+	void *ret;
+
+	ret = kvmalloc_node(size, flags, node);
+	if (is_vmalloc_addr(ret)) {
+		/*
+		 * Make sure we don't trigger recursive page faults in the
+		 * tracing fast path.
+		 */
+		wrapper_vmalloc_sync_all();
+	}
+	return ret;
+}
+
+static inline
+void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
+{
+	return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
+}
+
+static inline
+void *lttng_kvmalloc(unsigned long size, gfp_t flags)
+{
+	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
+}
+
+static inline
+void *lttng_kvzalloc(unsigned long size, gfp_t flags)
+{
+	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
+}
+
+static inline
+void lttng_kvfree(const void *addr)
+{
+	kvfree(addr);
+}
+
+#else
+
+#include <linux/slab.h>
+
+/*
+ * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
+ */
+static inline
+void *__lttng_vmalloc_node_fallback(unsigned long size, unsigned long align,
+                         gfp_t gfp_mask, pgprot_t prot, int node, void *caller)
+{
+	void *ret;
+
+#ifdef CONFIG_KALLSYMS
+	/*
+	 * If we have KALLSYMS, get * __vmalloc_node which is not exported.
+	 */
+	void *(*lttng__vmalloc_node)(unsigned long size, unsigned long align,
+			gfp_t gfp_mask, pgprot_t prot, int node, void *caller);
+
+	lttng__vmalloc_node = (void *) kallsyms_lookup_funcptr("__vmalloc_node");
+	ret = lttng__vmalloc_node(size, align, gfp_mask, prot, node, caller);
+#else
+	/*
+	 * If we don't have KALLSYMS, fallback to kmalloc_node.
+	 */
+	ret = kmalloc_node(size, flags, node);
+#endif
+
+	return ret;
+}
+
+/**
+ * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
+ * failure, fall back to non-contiguous (vmalloc) allocation.
+ * @size: size of the request.
+ * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
+ *
+ * Uses kmalloc to get the memory but if the allocation fails then falls back
+ * to the vmalloc allocator. Use lttng_kvfree to free the memory.
+ *
+ * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
+ */
+static inline
+void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
+{
+	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);
+
+	/*
+	 * If the allocation fits in a single page, do not fallback.
+	 */
+	if (size <= PAGE_SIZE) {
+		return kmalloc_node(size, flags, node);
+	}
+
+	/*
+	 * Make sure that larger requests are not too disruptive - no OOM
+	 * killer and no allocation failure warnings as we have a fallback
+	 */
+	ret = kmalloc_node(size, flags | __GFP_NOWARN | __GFP_NORETRY, node);
+	if (!ret) {
+		if (node == NUMA_NO_NODE) {
+			/*
+			 * If no node was specified, use __vmalloc which is
+			 * always exported.
+			 */
+			ret = __vmalloc(size, flags | __GFP_HIGHMEM, PAGE_KERNEL);
+		} else {
+			/*
+			 * Otherwise, we need to select a node but __vmalloc_node
+			 * is not exported, use this fallback wrapper which uses
+			 * kallsyms if available or falls back to kmalloc_node.
+			 */
+			ret = __lttng_vmalloc_node_fallback(size, 1,
+					flags | __GFP_HIGHMEM, PAGE_KERNEL, node,
+					__builtin_return_address(0));
+		}
+
+		/*
+		 * Make sure we don't trigger recursive page faults in the
+		 * tracing fast path.
+		 */
+		wrapper_vmalloc_sync_all();
+	}
+	return ret;
+}
+
+static inline
+void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
+{
+	return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
+}
+
+static inline
+void *lttng_kvmalloc(unsigned long size, gfp_t flags)
+{
+	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
+}
+
+static inline
+void *lttng_kvzalloc(unsigned long size, gfp_t flags)
+{
+	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
+}
+
+static inline
+void lttng_kvfree(const void *addr)
+{
+	if (is_vmalloc_addr(addr)) {
+		vfree(addr);
+	} else {
+		kfree(addr);
+	}
+}
+#endif
+
 #endif /* _LTTNG_WRAPPER_VMALLOC_H */