From: Frank Ch. Eigler <fche@redhat.com>
Date: Wed, 21 May 2014 17:43:48 +0000 (-0400)
Subject: linux runtime: switch to vmalloc for context[] element allocation
X-Git-Tag: release-2.6~107^2~43
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=681120bbf7f233317c9372e3c43abdde7b31e22c;p=systemtap.git

linux runtime: switch to vmalloc for context[] element allocation

The new eventcount.stp changes can result in relatively large context
structures (33712 bytes each on f19/x86-64), which the stp_kmalloc
widget can sometimes fail to allocate.  Switching to the numa-aware
vmalloc front-end lets these allocations succeed.

TBD: those contexts shouldn't be that large.
---

diff --git a/runtime/linux/runtime_context.h b/runtime/linux/runtime_context.h
index 4789bfbde..a23638143 100644
--- a/runtime/linux/runtime_context.h
+++ b/runtime/linux/runtime_context.h
@@ -20,10 +20,10 @@ static int _stp_runtime_contexts_alloc(void)
 	for_each_possible_cpu(cpu) {
 		/* Module init, so in user context, safe to use
 		 * "sleeping" allocation. */
-		contexts[cpu] = _stp_kzalloc_gfp(sizeof(struct context),
-						 STP_ALLOC_SLEEP_FLAGS);
+                contexts[cpu] = _stp_vzalloc_node(sizeof (struct context),
+                                                  cpu_to_node(cpu));
 		if (contexts[cpu] == NULL) {
-			_stp_error ("context (size %lu) allocation failed",
+			_stp_error ("context (size %lu per cpu) allocation failed",
 				    (unsigned long) sizeof (struct context));
 			return -ENOMEM;
 		}
@@ -37,7 +37,7 @@ static void _stp_runtime_contexts_free(void)
 
 	for_each_possible_cpu(cpu) {
 		if (contexts[cpu] != NULL) {
-			_stp_kfree(contexts[cpu]);
+			_stp_vfree(contexts[cpu]);
 			contexts[cpu] = NULL;
 		}
 	}