pid: reduce code size by using a pointer to iterate over array

[safe/jmp/linux-2.6] / kernel / pid.c

diff --git a/kernel/pid.c b/kernel/pid.c
index 5fa1db4..2e17c9c 100644 (file)
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -36,12 +36,11 @@
 #include <linux/pid_namespace.h>
 #include <linux/init_task.h>
 #include <linux/syscalls.h>
-#include <linux/kmemleak.h>
 
 #define pid_hashfn(nr, ns)     \
        hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
 static struct hlist_head *pid_hash;
-static int pidhash_shift;
+static unsigned int pidhash_shift = 4;
 struct pid init_struct_pid = INIT_STRUCT_PID;
 
 int pid_max = PID_MAX_DEFAULT;
@@ -142,11 +141,12 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
                         * installing it:
                         */
                        spin_lock_irq(&pidmap_lock);
-                       if (map->page)
-                               kfree(page);
-                       else
+                       if (!map->page) {
                                map->page = page;
+                               page = NULL;
+                       }
                        spin_unlock_irq(&pidmap_lock);
+                       kfree(page);
                        if (unlikely(!map->page))
                                break;
                }
@@ -269,12 +269,11 @@ struct pid *alloc_pid(struct pid_namespace *ns)
        for (type = 0; type < PIDTYPE_MAX; ++type)
                INIT_HLIST_HEAD(&pid->tasks[type]);
 
+       upid = pid->numbers + ns->level;
        spin_lock_irq(&pidmap_lock);
-       for (i = ns->level; i >= 0; i--) {
-               upid = &pid->numbers[i];
+       for ( ; upid >= pid->numbers; --upid)
                hlist_add_head_rcu(&upid->pid_chain,
                                &pid_hash[pid_hashfn(upid->nr, upid->ns)]);
-       }
        spin_unlock_irq(&pidmap_lock);
 
 out:
@@ -500,25 +499,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
 void __init pidhash_init(void)
 {
        int i, pidhash_size;
-       unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT);
 
-       pidhash_shift = max(4, fls(megabytes * 4));
-       pidhash_shift = min(12, pidhash_shift);
+       pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18,
+                                          HASH_EARLY | HASH_SMALL,
+                                          &pidhash_shift, NULL, 4096);
        pidhash_size = 1 << pidhash_shift;
 
-       printk("PID hash table entries: %d (order: %d, %Zd bytes)\n",
-               pidhash_size, pidhash_shift,
-               pidhash_size * sizeof(struct hlist_head));
-
-       pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash)));
-       if (!pid_hash)
-               panic("Could not alloc pidhash!\n");
-       /*
-        * pid_hash contains references to allocated struct pid objects and it
-        * must be scanned by kmemleak to avoid false positives.
-        */
-       kmemleak_alloc(pid_hash, pidhash_size * sizeof(*(pid_hash)), 0,
-                      GFP_KERNEL);
        for (i = 0; i < pidhash_size; i++)
                INIT_HLIST_HEAD(&pid_hash[i]);
 }