+ mm-bootmem-drop-superfluous-range-check-when-freeing-pages-in-bulk.patch added to -mm tree

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The patch titled
     Subject: mm: bootmem: drop superfluous range check when freeing pages in bulk
has been added to the -mm tree.  Its filename is
     mm-bootmem-drop-superfluous-range-check-when-freeing-pages-in-bulk.patch

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*** Remember to use Documentation/SubmitChecklist when testing your code ***

See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this

The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: mm: bootmem: drop superfluous range check when freeing pages in bulk

The area node_bootmem_map represents is aligned to BITS_PER_LONG, and all
bits in any aligned word of that map valid.  When the represented area
extends beyond the end of the node, the non-existant pages will be marked
as reserved.

As a result, when freeing a page block, doing an explicit range check for
whether that block is within the node's range is redundant as the bitmap
is consulted anyway to see whether all pages in the block are unreserved.

Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reported-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/bootmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/bootmem.c~mm-bootmem-drop-superfluous-range-check-when-freeing-pages-in-bulk mm/bootmem.c
--- a/mm/bootmem.c~mm-bootmem-drop-superfluous-range-check-when-freeing-pages-in-bulk
+++ a/mm/bootmem.c
@@ -197,7 +197,7 @@ static unsigned long __init free_all_boo
 		idx = start - bdata->node_min_pfn;
 		vec = ~map[idx / BITS_PER_LONG];
 
-		if (aligned && vec == ~0UL && start + BITS_PER_LONG <= end) {
+		if (aligned && vec == ~0UL) {
 			int order = ilog2(BITS_PER_LONG);
 
 			__free_pages_bootmem(pfn_to_page(start), order);
_
Subject: Subject: mm: bootmem: drop superfluous range check when freeing pages in bulk

Patches currently in -mm which might be from hannes@xxxxxxxxxxx are

linux-next.patch
memcg-add-mem_cgroup_replace_page_cache-to-fix-lru-issue.patch
mm-page-writebackc-make-determine_dirtyable_memory-static-again.patch
vmscan-promote-shared-file-mapped-pages.patch
vmscan-activate-executable-pages-after-first-usage.patch
mm-do-not-stall-in-synchronous-compaction-for-thp-allocations.patch
mm-do-not-stall-in-synchronous-compaction-for-thp-allocations-v3.patch
vmscan-add-task-name-to-warn_scan_unevictable-messages.patch
mm-page_alloc-remove-order-assumption-from-__free_pages_bootmem.patch
mm-page_alloc-generalize-order-handling-in-__free_pages_bootmem.patch
mm-bootmem-drop-superfluous-range-check-when-freeing-pages-in-bulk.patch
mm-bootmem-try-harder-to-free-pages-in-bulk.patch
cgroups-add-res_counter_write_u64-api.patch
cgroups-new-resource-counter-inheritance-api.patch
cgroups-add-previous-cgroup-in-can_attach_task-attach_task-callbacks.patch
cgroups-new-cancel_attach_task-subsystem-callback.patch
cgroups-ability-to-stop-res-charge-propagation-on-bounded-ancestor.patch
cgroups-add-res-counter-common-ancestor-searching.patch
res_counter-allow-charge-failure-pointer-to-be-null.patch
cgroups-pull-up-res-counter-charge-failure-interpretation-to-caller.patch
cgroups-allow-subsystems-to-cancel-a-fork.patch
cgroups-add-a-task-counter-subsystem.patch
memcg-make-mem_cgroup_split_huge_fixup-more-efficient.patch
memcg-fix-pgpgin-pgpgout-documentation.patch
mm-page_cgroup-check-page_cgroup-arrays-in-lookup_page_cgroup-only-when-necessary.patch

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