diff options
| author | Robin Holt <robin.m.holt@gmail.com> | 2013-11-12 15:07:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-13 12:09:04 +0900 |
| commit | 309d0b3917387b48d1fa1a15aa6762de489c9123 (patch) | |
| tree | 7b541eb4d6e4ca104b7b4323776113028ee9f9a7 | |
| parent | b9921ecdee66984b00c38c00a358ef3f611d2b50 (diff) | |
mm/nobootmem.c: have __free_pages_memory() free in larger chunks.
On large memory machines it can take a few minutes to get through
free_all_bootmem().
Currently, when free_all_bootmem() calls __free_pages_memory(), the number
of contiguous pages that __free_pages_memory() passes to the buddy
allocator is limited to BITS_PER_LONG. BITS_PER_LONG was originally
chosen to keep things similar to mm/nobootmem.c. But it is more efficient
to limit it to MAX_ORDER.
base new change
8TB 202s 172s 30s
16TB 401s 351s 50s
That is around 1%-3% improvement on total boot time.
This patch was spun off from the boot time rfc Robin and I had been
working on.
Signed-off-by: Robin Holt <robin.m.holt@gmail.com>
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Robin Holt <robinmholt@linux.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/nobootmem.c | 25 |
1 files changed, 8 insertions, 17 deletions
diff --git a/mm/nobootmem.c b/mm/nobootmem.c index 61107cf55bb3..2c254d374655 100644 --- a/mm/nobootmem.c +++ b/mm/nobootmem.c @@ -82,27 +82,18 @@ void __init free_bootmem_late(unsigned long addr, unsigned long size) static void __init __free_pages_memory(unsigned long start, unsigned long end) { - unsigned long i, start_aligned, end_aligned; - int order = ilog2(BITS_PER_LONG); + int order; - start_aligned = (start + (BITS_PER_LONG - 1)) & ~(BITS_PER_LONG - 1); - end_aligned = end & ~(BITS_PER_LONG - 1); + while (start < end) { + order = min(MAX_ORDER - 1UL, __ffs(start)); - if (end_aligned <= start_aligned) { - for (i = start; i < end; i++) - __free_pages_bootmem(pfn_to_page(i), 0); + while (start + (1UL << order) > end) + order--; - return; - } - - for (i = start; i < start_aligned; i++) - __free_pages_bootmem(pfn_to_page(i), 0); + __free_pages_bootmem(pfn_to_page(start), order); - for (i = start_aligned; i < end_aligned; i += BITS_PER_LONG) - __free_pages_bootmem(pfn_to_page(i), order); - - for (i = end_aligned; i < end; i++) - __free_pages_bootmem(pfn_to_page(i), 0); + start += (1UL << order); + } } static unsigned long __init __free_memory_core(phys_addr_t start, |