x86: fix trim mtrr not to setup_memory two times

we could call find_max_pfn() directly instead of setup_memory() to get
max_pfn needed for mtrr trimming.

otherwise setup_memory() is called two times... that is duplicated...

[ mingo@elte.hu: both Thomas and me simulated a double call to
  setup_bootmem_allocator() and can confirm that it is a real bug
  which can hang in certain configs. It's not been reported yet but
  that is probably due to the relatively scarce nature of
  MTRR-trimming systems. ]

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index a1d7071..2b3e5d4 100644 (file)
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -406,8 +406,6 @@ static unsigned long __init setup_memory(void)
         */
        min_low_pfn = PFN_UP(init_pg_tables_end);
 
-       find_max_pfn();
-
        max_low_pfn = find_max_low_pfn();
 
 #ifdef CONFIG_HIGHMEM
@@ -764,12 +762,13 @@ void __init setup_arch(char **cmdline_p)
        if (efi_enabled)
                efi_init();
 
-       max_low_pfn = setup_memory();
-
        /* update e820 for memory not covered by WB MTRRs */
+       find_max_pfn();
        mtrr_bp_init();
        if (mtrr_trim_uncached_memory(max_pfn))
-               max_low_pfn = setup_memory();
+               find_max_pfn();
+
+       max_low_pfn = setup_memory();
 
 #ifdef CONFIG_VMI
        /*

diff --git a/arch/x86/mm/discontig_32.c b/arch/x86/mm/discontig_32.c
index c394ca0..8e25e06 100644 (file)
--- a/arch/x86/mm/discontig_32.c
+++ b/arch/x86/mm/discontig_32.c
@@ -324,7 +324,6 @@ unsigned long __init setup_memory(void)
         * this space and use it to adjust the boundary between ZONE_NORMAL
         * and ZONE_HIGHMEM.
         */
-       find_max_pfn();
        get_memcfg_numa();
 
        kva_pages = calculate_numa_remap_pages();