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mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist 

The kernel currently clamps large system hashes to MAX_ORDER when hashdist
is not set, which is rather arbitrary.

vmalloc space is limited on 32-bit machines, but this shouldn't result in
much more used because of small physical memory limiting system hash
sizes.

Include "vmalloc" or "linear" in the kernel log message.

Link: http://lkml.kernel.org/r/20190605144814.29319-1-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nicholas Piggin 2019-07-11 20:59:09 -07:00 committed by Linus Torvalds
parent d9009d67f4
commit ec11408a16
1 changed files with 9 additions and 7 deletions
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16
mm/page_alloc.c
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@ -7981,6 +7981,7 @@ void *__init alloc_large_system_hash(const char *tablename,
unsigned long log2qty, size;
void *table = NULL;
gfp_t gfp_flags;
bool virt;
/* allow the kernel cmdline to have a say */
if (!numentries) {
@ -8037,6 +8038,7 @@ void *__init alloc_large_system_hash(const char *tablename,
gfp_flags = (flags & HASH_ZERO) ? GFP_ATOMIC | __GFP_ZERO : GFP_ATOMIC;
do {
virt = false;
size = bucketsize << log2qty;
if (flags & HASH_EARLY) {
if (flags & HASH_ZERO)
@ -8044,26 +8046,26 @@ void *__init alloc_large_system_hash(const char *tablename,
else
table = memblock_alloc_raw(size,
SMP_CACHE_BYTES);
} else if (hashdist) {
} else if (get_order(size) >= MAX_ORDER || hashdist) {
table = __vmalloc(size, gfp_flags, PAGE_KERNEL);
virt = true;
} else {
/*
* If bucketsize is not a power-of-two, we may free
* some pages at the end of hash table which
* alloc_pages_exact() automatically does
*/
if (get_order(size) < MAX_ORDER) {
table = alloc_pages_exact(size, gfp_flags);
kmemleak_alloc(table, size, 1, gfp_flags);
}
table = alloc_pages_exact(size, gfp_flags);
kmemleak_alloc(table, size, 1, gfp_flags);
}
} while (!table && size > PAGE_SIZE && --log2qty);
if (!table)
panic("Failed to allocate %s hash table\n", tablename);
pr_info("%s hash table entries: %ld (order: %d, %lu bytes)\n",
tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size);
pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
virt ? "vmalloc" : "linear");
if (_hash_shift)
*_hash_shift = log2qty;