From 8a942fdea560d4ac0e9d9fabcd5201ad20e0c382 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 30 Jun 2015 14:56:55 -0700 Subject: 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 Tested-by: Nate Zimmer Tested-by: Waiman Long Tested-by: Daniel J Blueman Acked-by: Pekka Enberg Cc: Robin Holt Cc: Nate Zimmer Cc: Dave Hansen Cc: Waiman Long Cc: Scott Norton Cc: "Luck, Tony" Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ia64/mm/numa.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c index ea21d4cad540..aa19b7ac8222 100644 --- a/arch/ia64/mm/numa.c +++ b/arch/ia64/mm/numa.c @@ -58,27 +58,22 @@ paddr_to_nid(unsigned long paddr) * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where * the section resides. */ -int __meminit __early_pfn_to_nid(unsigned long pfn) +int __meminit __early_pfn_to_nid(unsigned long pfn, + struct mminit_pfnnid_cache *state) { int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec; - /* - * NOTE: The following SMP-unsafe globals are only used early in boot - * when the kernel is running single-threaded. - */ - static int __meminitdata last_ssec, last_esec; - static int __meminitdata last_nid; - if (section >= last_ssec && section < last_esec) - return last_nid; + if (section >= state->last_start && section < state->last_end) + return state->last_nid; for (i = 0; i < num_node_memblks; i++) { ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT; esec = (node_memblk[i].start_paddr + node_memblk[i].size + ((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT; if (section >= ssec && section < esec) { - last_ssec = ssec; - last_esec = esec; - last_nid = node_memblk[i].nid; + state->last_start = ssec; + state->last_end = esec; + state->last_nid = node_memblk[i].nid; return node_memblk[i].nid; } } -- cgit v1.2.3-58-ga151