postgresql/postgresql-oom_score_adj.patch

53 lines
2.1 KiB
Diff

Back-patch upstream's 9.2 patch to add support for setting oom_score_adj.
diff -Naur postgresql-9.1.4.orig/src/backend/postmaster/fork_process.c postgresql-9.1.4/src/backend/postmaster/fork_process.c
--- postgresql-9.1.4.orig/src/backend/postmaster/fork_process.c 2012-05-31 19:07:09.000000000 -0400
+++ postgresql-9.1.4/src/backend/postmaster/fork_process.c 2012-07-14 17:55:42.911859485 -0400
@@ -68,12 +68,40 @@
* process sizes *including shared memory*. (This is unbelievably
* stupid, but the kernel hackers seem uninterested in improving it.)
* Therefore it's often a good idea to protect the postmaster by
- * setting its oom_adj value negative (which has to be done in a
- * root-owned startup script). If you just do that much, all child
+ * setting its oom_score_adj value negative (which has to be done in a
+ * root-owned startup script). If you just do that much, all child
* processes will also be protected against OOM kill, which might not
- * be desirable. You can then choose to build with LINUX_OOM_ADJ
- * #defined to 0, or some other value that you want child processes to
- * adopt here.
+ * be desirable. You can then choose to build with
+ * LINUX_OOM_SCORE_ADJ #defined to 0, or to some other value that you
+ * want child processes to adopt here.
+ */
+#ifdef LINUX_OOM_SCORE_ADJ
+ {
+ /*
+ * Use open() not stdio, to ensure we control the open flags. Some
+ * Linux security environments reject anything but O_WRONLY.
+ */
+ int fd = open("/proc/self/oom_score_adj", O_WRONLY, 0);
+
+ /* We ignore all errors */
+ if (fd >= 0)
+ {
+ char buf[16];
+ int rc;
+
+ snprintf(buf, sizeof(buf), "%d\n", LINUX_OOM_SCORE_ADJ);
+ rc = write(fd, buf, strlen(buf));
+ (void) rc;
+ close(fd);
+ }
+ }
+#endif /* LINUX_OOM_SCORE_ADJ */
+
+ /*
+ * Older Linux kernels have oom_adj not oom_score_adj. This works
+ * similarly except with a different scale of adjustment values.
+ * If it's necessary to build Postgres to work with either API,
+ * you can define both LINUX_OOM_SCORE_ADJ and LINUX_OOM_ADJ.
*/
#ifdef LINUX_OOM_ADJ
{