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authorMel Gorman <mgorman@suse.de>2015-06-30 14:56:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-30 19:44:56 -0700
commit8a942fdea560d4ac0e9d9fabcd5201ad20e0c382 (patch)
tree452c0f5acccf96ffc54748a44ab5bc788f7dbffc /include/linux/mmzone.h
parentd70ddd7a5d9aa335f9b4b0c3d879e1e70ee1e4e3 (diff)
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mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nid
__early_pfn_to_nid() use static variables to cache recent lookups as memblock lookups are very expensive but it assumes that memory initialisation is single-threaded. Parallel initialisation of struct pages will break that assumption so this patch makes __early_pfn_to_nid() SMP-safe by requiring the caller to cache recent search information. early_pfn_to_nid() keeps the same interface but is only safe to use early in boot due to the use of a global static variable. meminit_pfn_in_nid() is an SMP-safe version that callers must maintain their own state for. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h16
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 54d74f6eb233..b2473d822549 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1216,10 +1216,24 @@ void sparse_init(void);
#define sparse_index_init(_sec, _nid) do {} while (0)
#endif /* CONFIG_SPARSEMEM */
+/*
+ * During memory init memblocks map pfns to nids. The search is expensive and
+ * this caches recent lookups. The implementation of __early_pfn_to_nid
+ * may treat start/end as pfns or sections.
+ */
+struct mminit_pfnnid_cache {
+ unsigned long last_start;
+ unsigned long last_end;
+ int last_nid;
+};
+
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
bool early_pfn_in_nid(unsigned long pfn, int nid);
+bool meminit_pfn_in_nid(unsigned long pfn, int node,
+ struct mminit_pfnnid_cache *state);
#else
-#define early_pfn_in_nid(pfn, nid) (1)
+#define early_pfn_in_nid(pfn, nid) (1)
+#define meminit_pfn_in_nid(pfn, nid, state) (1)
#endif
#ifndef early_pfn_valid