- (dtucker) [openbsd-compat/port-linux.c] Bug #1838: Add support for the new

   Linux OOM-killer magic values that changed in 2.6.36 kernels, with fallback
   to the old values.  Feedback from vapier at gentoo org and djm, ok djm.

2 files changed, 39 insertions, 19 deletions

diff --git a/ChangeLog b/ChangeLog
index 7dda03e0..e64a550f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,9 @@
    its unique snowflake of a gdb error to the ones we look for.
  - (djm) [regress/agent-getpeereid.sh] leave stdout attached when running
    ssh-add to avoid $SUDO failures on Linux
+ - (dtucker) [openbsd-compat/port-linux.c] Bug #1838: Add support for the new
+   Linux OOM-killer magic values that changed in 2.6.36 kernels, with fallback
+   to the old values.  Feedback from vapier at gentoo org and djm, ok djm.
 
 20110116
  - (dtucker) [Makefile.in configure.ac regress/kextype.sh] Skip sha256-based
diff --git a/openbsd-compat/port-linux.c b/openbsd-compat/port-linux.c
index 86d16dc6..d89101d1 100644
--- a/openbsd-compat/port-linux.c
+++ b/openbsd-compat/port-linux.c
@@ -1,4 +1,4 @@
-/* $Id: port-linux.c,v 1.9 2010/09/10 00:30:25 dtucker Exp $ */
+/* $Id: port-linux.c,v 1.10 2011/01/17 00:56:00 dtucker Exp $ */
 
 /*
  * Copyright (c) 2005 Daniel Walsh <dwalsh@redhat.com>
@@ -208,14 +208,22 @@ ssh_selinux_change_context(const char *newname)
 #endif /* WITH_SELINUX */
 
 #ifdef LINUX_OOM_ADJUST
-#define OOM_ADJ_PATH	"/proc/self/oom_adj"
 /*
- * The magic "don't kill me", as documented in eg:
+ * The magic "don't kill me" values, old and new, as documented in eg:
  * http://lxr.linux.no/#linux+v2.6.32/Documentation/filesystems/proc.txt
+ * http://lxr.linux.no/#linux+v2.6.36/Documentation/filesystems/proc.txt
  */
-#define OOM_ADJ_NOKILL	-17
 
 static int oom_adj_save = INT_MIN;
+static char *oom_adj_path = NULL;
+struct {
+	char *path;
+	int value;
+} oom_adjust[] = {
+	{"/proc/self/oom_score_adj", -1000},	/* kernels >= 2.6.36 */
+	{"/proc/self/oom_adj", -17},		/* kernels <= 2.6.35 */
+	{NULL, 0},
+};
 
 /*
  * Tell the kernel's out-of-memory killer to avoid sshd.
@@ -224,23 +232,31 @@ static int oom_adj_save = INT_MIN;
 void
 oom_adjust_setup(void)
 {
+	int i, value;
 	FILE *fp;
 
 	debug3("%s", __func__);
-	if ((fp = fopen(OOM_ADJ_PATH, "r+")) != NULL) {
-		if (fscanf(fp, "%d", &oom_adj_save) != 1)
-			verbose("error reading %s: %s", OOM_ADJ_PATH, strerror(errno));
-		else {
-			rewind(fp);
-			if (fprintf(fp, "%d\n", OOM_ADJ_NOKILL) <= 0)
-				verbose("error writing %s: %s",
-				    OOM_ADJ_PATH, strerror(errno));
-			else
-				verbose("Set %s from %d to %d",
-				    OOM_ADJ_PATH, oom_adj_save, OOM_ADJ_NOKILL);
+	 for (i = 0; oom_adjust[i].path != NULL; i++) {
+		oom_adj_path = oom_adjust[i].path;
+		value = oom_adjust[i].value;
+		if ((fp = fopen(oom_adj_path, "r+")) != NULL) {
+			if (fscanf(fp, "%d", &oom_adj_save) != 1)
+				verbose("error reading %s: %s", oom_adj_path,
+				    strerror(errno));
+			else {
+				rewind(fp);
+				if (fprintf(fp, "%d\n", value) <= 0)
+					verbose("error writing %s: %s",
+					   oom_adj_path, strerror(errno));
+				else
+					verbose("Set %s from %d to %d",
+					   oom_adj_path, oom_adj_save, value);
+			}
+			fclose(fp);
+			return;
 		}
-		fclose(fp);
 	}
+	oom_adj_path = NULL;
 }
 
 /* Restore the saved OOM adjustment */
@@ -250,13 +266,14 @@ oom_adjust_restore(void)
 	FILE *fp;
 
 	debug3("%s", __func__);
-	if (oom_adj_save == INT_MIN || (fp = fopen(OOM_ADJ_PATH, "w")) == NULL)
+	if (oom_adj_save == INT_MIN || oom_adj_save == NULL ||
+	    (fp = fopen(oom_adj_path, "w")) == NULL)
 		return;
 
 	if (fprintf(fp, "%d\n", oom_adj_save) <= 0)
-		verbose("error writing %s: %s", OOM_ADJ_PATH, strerror(errno));
+		verbose("error writing %s: %s", oom_adj_path, strerror(errno));
 	else
-		verbose("Set %s to %d", OOM_ADJ_PATH, oom_adj_save);
+		verbose("Set %s to %d", oom_adj_path, oom_adj_save);
 
 	fclose(fp);
 	return;