The patch titled
Subject: mm: meminit: minimise number of pfn->page lookups during initialisation
has been added to the -mm tree. Its filename is
mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: mm: meminit: minimise number of pfn->page lookups during initialisation
Deferred struct page initialisation is using pfn_to_page() on every PFN
unnecessarily. This patch minimises the number of lookups and scheduler
checks.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Daniel J Blueman <daniel@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Nathan Zimmer <nzimmer@xxxxxxx>
Cc: Robin Holt <holt@xxxxxxx>
Cc: Scott Norton <scott.norton@xxxxxx>
Cc: Waiman Long <waiman.long@xxxxxx>
Cc: "Luck, Tony" <tony.luck@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)
diff -puN mm/page_alloc.c~mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation mm/page_alloc.c
--- a/mm/page_alloc.c~mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation
+++ a/mm/page_alloc.c
@@ -1080,6 +1080,7 @@ void __defermem_init deferred_init_memma
for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) {
unsigned long pfn, end_pfn;
+ struct page *page = NULL;
end_pfn = min(walk_end, zone_end_pfn(zone));
pfn = first_init_pfn;
@@ -1089,13 +1090,32 @@ void __defermem_init deferred_init_memma
pfn = zone->zone_start_pfn;
for (; pfn < end_pfn; pfn++) {
- struct page *page;
-
- if (!pfn_valid(pfn))
+ if (!pfn_valid_within(pfn))
continue;
- if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state))
+ /*
+ * Ensure pfn_valid is checked every
+ * MAX_ORDER_NR_PAGES for memory holes
+ */
+ if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+ if (!pfn_valid(pfn)) {
+ page = NULL;
+ continue;
+ }
+ }
+
+ if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) {
+ page = NULL;
continue;
+ }
+
+ /* Minimise pfn page lookups and scheduler checks */
+ if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) {
+ page++;
+ } else {
+ page = pfn_to_page(pfn);
+ cond_resched();
+ }
if (page->flags) {
VM_BUG_ON(page_zone(page) != zone);
@@ -1104,7 +1124,6 @@ void __defermem_init deferred_init_memma
__init_single_page(page, pfn, zid, nid);
__free_pages_boot_core(page, pfn, 0);
- cond_resched();
}
first_init_pfn = max(end_pfn, first_init_pfn);
}
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
jbd2-revert-must-not-fail-allocation-loops-back-to-gfp_nofail.patch
thp-cleanup-how-khugepaged-enters-freezer.patch
mm-new-mm-hook-framework.patch
mm-new-arch_remap-hook.patch
powerpc-mm-tracking-vdso-remap.patch
memblock-introduce-a-for_each_reserved_mem_region-iterator.patch
mm-meminit-move-page-initialization-into-a-separate-function.patch
mm-meminit-only-set-page-reserved-in-the-memblock-region.patch
mm-page_alloc-pass-pfn-to-__free_pages_bootmem.patch
mm-meminit-make-__early_pfn_to_nid-smp-safe-and-introduce-meminit_pfn_in_nid.patch
mm-meminit-inline-some-helper-functions.patch
mm-meminit-initialise-a-subset-of-struct-pages-if-config_deferred_struct_page_init-is-set.patch
mm-meminit-initialise-a-subset-of-struct-pages-if-config_deferred_struct_page_init-is-set-fix.patch
mm-meminit-initialise-remaining-struct-pages-in-parallel-with-kswapd.patch
mm-meminit-initialise-remaining-struct-pages-in-parallel-with-kswapd-fix.patch
mm-meminit-minimise-number-of-pfn-page-lookups-during-initialisation.patch
x86-mm-enable-deferred-struct-page-initialisation-on-x86-64.patch
mm-meminit-free-pages-in-large-chunks-where-possible.patch
mm-meminit-reduce-number-of-times-pageblocks-are-set-during-struct-page-init.patch
mm-meminit-remove-mminit_verify_page_links.patch
page-flags-trivial-cleanup-for-pagetrans-helpers.patch
page-flags-introduce-page-flags-policies-wrt-compound-pages.patch
page-flags-define-pg_locked-behavior-on-compound-pages.patch
page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch
page-flags-define-behavior-slb-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch
page-flags-define-pg_reserved-behavior-on-compound-pages.patch
page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch
page-flags-define-pg_swapcache-behavior-on-compound-pages.patch
page-flags-define-pg_mlocked-behavior-on-compound-pages.patch
page-flags-define-pg_uncached-behavior-on-compound-pages.patch
page-flags-define-pg_uptodate-behavior-on-compound-pages.patch
page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch
mm-sanitize-page-mapping-for-tail-pages.patch
mm-vmscan-do-not-throttle-based-on-pfmemalloc-reserves-if-node-has-no-reclaimable-pages.patch
mm-vmscan-fix-the-page-state-calculation-in-too_many_isolated.patch
mm-move-lazy-free-pages-to-inactive-list.patch
mm-move-lazy-free-pages-to-inactive-list-fix.patch
mm-move-lazy-free-pages-to-inactive-list-fix-fix.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
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