Commit 2c85f51d222ccdd8c401d77a36b723a89156810d
Committed by
Linus Torvalds
Linus Torvalds
1 parent
3c1596efe1
Exists in
master
and in
39 other branches
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>
Showing 3 changed files with 16 additions and 17 deletions Side-by-side Diff
include/linux/bootmem.h
| ... | ... | @@ -132,9 +132,6 @@ |
| 132 | 132 | } |
| 133 | 133 | #endif /* CONFIG_HAVE_ARCH_ALLOC_REMAP */ |
| 134 | 134 | |
| 135 | -extern unsigned long __meminitdata nr_kernel_pages; | |
| 136 | -extern unsigned long __meminitdata nr_all_pages; | |
| 137 | - | |
| 138 | 135 | extern void *alloc_large_system_hash(const char *tablename, |
| 139 | 136 | unsigned long bucketsize, |
| 140 | 137 | unsigned long numentries, |
| ... | ... | @@ -145,6 +142,8 @@ |
| 145 | 142 | unsigned long limit); |
| 146 | 143 | |
| 147 | 144 | #define HASH_EARLY 0x00000001 /* Allocating during early boot? */ |
| 145 | +#define HASH_SMALL 0x00000002 /* sub-page allocation allowed, min | |
| 146 | + * shift passed via *_hash_shift */ | |
| 148 | 147 | |
| 149 | 148 | /* Only NUMA needs hash distribution. 64bit NUMA architectures have |
| 150 | 149 | * sufficient vmalloc space. |
kernel/pid.c
| ... | ... | @@ -40,7 +40,7 @@ |
| 40 | 40 | #define pid_hashfn(nr, ns) \ |
| 41 | 41 | hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift) |
| 42 | 42 | static struct hlist_head *pid_hash; |
| 43 | -static int pidhash_shift; | |
| 43 | +static unsigned int pidhash_shift = 4; | |
| 44 | 44 | struct pid init_struct_pid = INIT_STRUCT_PID; |
| 45 | 45 | |
| 46 | 46 | int pid_max = PID_MAX_DEFAULT; |
| 47 | 47 | |
| 48 | 48 | |
| ... | ... | @@ -499,19 +499,12 @@ |
| 499 | 499 | void __init pidhash_init(void) |
| 500 | 500 | { |
| 501 | 501 | int i, pidhash_size; |
| 502 | - unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT); | |
| 503 | 502 | |
| 504 | - pidhash_shift = max(4, fls(megabytes * 4)); | |
| 505 | - pidhash_shift = min(12, pidhash_shift); | |
| 503 | + pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18, | |
| 504 | + HASH_EARLY | HASH_SMALL, | |
| 505 | + &pidhash_shift, NULL, 4096); | |
| 506 | 506 | pidhash_size = 1 << pidhash_shift; |
| 507 | 507 | |
| 508 | - printk("PID hash table entries: %d (order: %d, %Zd bytes)\n", | |
| 509 | - pidhash_size, pidhash_shift, | |
| 510 | - pidhash_size * sizeof(struct hlist_head)); | |
| 511 | - | |
| 512 | - pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash))); | |
| 513 | - if (!pid_hash) | |
| 514 | - panic("Could not alloc pidhash!\n"); | |
| 515 | 508 | for (i = 0; i < pidhash_size; i++) |
| 516 | 509 | INIT_HLIST_HEAD(&pid_hash[i]); |
| 517 | 510 | } |
mm/page_alloc.c
| ... | ... | @@ -124,8 +124,8 @@ |
| 124 | 124 | |
| 125 | 125 | int min_free_kbytes = 1024; |
| 126 | 126 | |
| 127 | -unsigned long __meminitdata nr_kernel_pages; | |
| 128 | -unsigned long __meminitdata nr_all_pages; | |
| 127 | +static unsigned long __meminitdata nr_kernel_pages; | |
| 128 | +static unsigned long __meminitdata nr_all_pages; | |
| 129 | 129 | static unsigned long __meminitdata dma_reserve; |
| 130 | 130 | |
| 131 | 131 | #ifdef CONFIG_ARCH_POPULATES_NODE_MAP |
| ... | ... | @@ -4821,7 +4821,14 @@ |
| 4821 | 4821 | numentries <<= (PAGE_SHIFT - scale); |
| 4822 | 4822 | |
| 4823 | 4823 | /* Make sure we've got at least a 0-order allocation.. */ |
| 4824 | - if (unlikely((numentries * bucketsize) < PAGE_SIZE)) | |
| 4824 | + if (unlikely(flags & HASH_SMALL)) { | |
| 4825 | + /* Makes no sense without HASH_EARLY */ | |
| 4826 | + WARN_ON(!(flags & HASH_EARLY)); | |
| 4827 | + if (!(numentries >> *_hash_shift)) { | |
| 4828 | + numentries = 1UL << *_hash_shift; | |
| 4829 | + BUG_ON(!numentries); | |
| 4830 | + } | |
| 4831 | + } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) | |
| 4825 | 4832 | numentries = PAGE_SIZE / bucketsize; |
| 4826 | 4833 | } |
| 4827 | 4834 | numentries = roundup_pow_of_two(numentries); |