mm: also use alloc_large_system_hash() for the PID hash table
This is being done by allowing boot time allocations to specify that they
may want a sub-page sized amount of memory.
Overall this seems more consistent with the other hash table allocations,
and allows making two supposedly mm-only variables really mm-only
(nr_{kernel,all}_pages).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/pid.c b/kernel/pid.c
index 31310b5..d3f722d 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -40,7 +40,7 @@
#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;
@@ -499,19 +499,12 @@
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");
for (i = 0; i < pidhash_size; i++)
INIT_HLIST_HEAD(&pid_hash[i]);
}