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authorRobin Holt <robin.m.holt@gmail.com>2013-11-13 03:07:23 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 07:09:04 +0400
commit309d0b3917387b48d1fa1a15aa6762de489c9123 (patch)
tree7b541eb4d6e4ca104b7b4323776113028ee9f9a7 /mm/nobootmem.c
parentb9921ecdee66984b00c38c00a358ef3f611d2b50 (diff)
downloadlinux-309d0b3917387b48d1fa1a15aa6762de489c9123.tar.xz
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>
Diffstat (limited to 'mm/nobootmem.c')
-rw-r--r--mm/nobootmem.c25
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,