readahead: make candidate for early OOM kill

src/readahead-collect.c

@@ -57,7 +57,6 @@
  * - read ahead directories
  * - sd_readahead_cancel
  * - gzip?
- * - oom adjust
  * - remount rw
  * - are filenames from anotify normalized regards /../ and // and /./?
  * - does ioprio_set work with fadvise()?
@@ -216,6 +215,8 @@ static int collect(const char *root) {
 
         assert(root);
 
+        write_one_line_file("/proc/self/oom_score_adj", "1000");
+
         if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)) < 0)
                 log_warning("Failed to set IDLE IO priority class: %m");
 

src/readahead-replay.c

@@ -119,6 +119,8 @@ static int replay(const char *root) {
 
         assert(root);
 
+        write_one_line_file("/proc/self/oom_score_adj", "1000");
+
         if (asprintf(&pack_fn, "%s/.readahead", root) < 0) {
                 log_error("Out of memory");
                 r = -ENOMEM;