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authorTejun Heo <tj@kernel.org>2011-03-04 10:26:36 +0100
committerTejun Heo <tj@kernel.org>2011-03-04 10:26:36 +0100
commitf89112502805c1f6a6955f90ad158e538edb319d (patch)
treec8fff8bdf2a2297e92e78b8661c9e8b405a7b304 /arch/x86/kernel/setup.c
parenteb8c1e2c830fc25c93bc94e215ed387fe142a98d (diff)
x86-64, NUMA: Revert NUMA affine page table allocation
This patch reverts NUMA affine page table allocation added by commit 1411e0ec31 (x86-64, numa: Put pgtable to local node memory). The commit made an undocumented change where the kernel linear mapping strictly follows intersection of e820 memory map and NUMA configuration. If the physical memory configuration has holes or NUMA nodes are not properly aligned, this leads to using unnecessarily smaller mapping size which leads to increased TLB pressure. For details, http://thread.gmane.org/gmane.linux.kernel/1104672 Patches to fix the problem have been proposed but the underlying code needs more cleanup and the approach itself seems a bit heavy handed and it has been determined to revert the feature for now and come back to it in the next developement cycle. http://thread.gmane.org/gmane.linux.kernel/1105959 As init_memory_mapping_high() callsites have been consolidated since the commit, reverting is done manually. Also, the RED-PEN comment in arch/x86/mm/init.c is not restored as the problem no longer exists with memblock based top-down early memory allocation. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/setup.c')
-rw-r--r--arch/x86/kernel/setup.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 46e684f85b3..c3a606c41ce 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -963,6 +963,14 @@ void __init setup_arch(char **cmdline_p)
max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
max_pfn_mapped = max_low_pfn_mapped;
+#ifdef CONFIG_X86_64
+ if (max_pfn > max_low_pfn) {
+ max_pfn_mapped = init_memory_mapping(1UL<<32,
+ max_pfn<<PAGE_SHIFT);
+ /* can we preseve max_low_pfn ?*/
+ max_low_pfn = max_pfn;
+ }
+#endif
memblock.current_limit = get_max_mapped();
/*