---

yaml
---
r: 198814
b: refs/heads/master
c: 72680a1
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bd4fb654e3a0d83ca8cb138c5e3e6e65407e119c
+refs/heads/master: 72680a191b934377430032f93af15ef50aafb3a8

trunk/include/linux/threads.h

@@ -33,4 +33,13 @@
 #define PID_MAX_LIMIT (CONFIG_BASE_SMALL ? PAGE_SIZE * 8 : \
 	(sizeof(long) > 4 ? 4 * 1024 * 1024 : PID_MAX_DEFAULT))
 
+/*
+ * Define a minimum number of pids per cpu.  Heuristically based
+ * on original pid max of 32k for 32 cpus.  Also, increase the
+ * minimum settable value for pid_max on the running system based
+ * on similar defaults.  See kernel/pid.c:pidmap_init() for details.
+ */
+#define PIDS_PER_CPU_DEFAULT	1024
+#define PIDS_PER_CPU_MIN	8
+
 #endif

trunk/kernel/pid.c

@@ -513,6 +513,13 @@ void __init pidhash_init(void)
 
 void __init pidmap_init(void)
 {
+	/* bump default and minimum pid_max based on number of cpus */
+	pid_max = min(pid_max_max, max_t(int, pid_max,
+				PIDS_PER_CPU_DEFAULT * num_possible_cpus()));
+	pid_max_min = max_t(int, pid_max_min,
+				PIDS_PER_CPU_MIN * num_possible_cpus());
+	pr_info("pid_max: default: %u minimum: %u\n", pid_max, pid_max_min);
+
 	init_pid_ns.pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL);
 	/* Reserve PID 0. We never call free_pidmap(0) */
 	set_bit(0, init_pid_ns.pidmap[0].page);