path: root/arch
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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-03 12:26:04 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-06 19:19:40 -0700
commit0c335d55cee6c632008a1b0cf34c2d12d3ee14e7 (patch)
tree97f7d3d63675bef2f290697eb32401c92819784b /arch
parentfcd35f5a3f850a5644bf1759e85d0811dfe4d6d2 (diff)
Revert "powerpc/numa: Fix percpu allocations to be NUMA aware"
This reverts commit 8c92870bdbf20b5fa5150a2c8bf53ab498516b24 which is commit ba4a648f12f4cd0a8003dd229b6ca8a53348ee4b upstream. Michal Hocko writes: JFYI. We have encountered a regression after applying this patch on a large ppc machine. While the patch is the right thing to do it doesn't work well with the current vmalloc area size on ppc and large machines where NUMA nodes are very far from each other. Just for the reference the boot fails on such a machine with bunch of warning preceeding it. See http://lkml.kernel.org/r/20170724134240.GL25221@dhcp22.suse.cz It seems the right thing to do is to enlarge the vmalloc space on ppc but this is not the case in the upstream kernel yet AFAIK. It is also questionable whether that is a stable material but I will decision on you here. We have reverted this patch from our 4.4 based kernel. Newer kernels do not have enlarged vmalloc space yet AFAIK so they won't work properly eiter. This bug is quite rare though because you need a specific HW configuration to trigger the issue - namely NUMA nodes have to be far away from each other in the physical memory space. Cc: Michal Hocko <mhocko@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
2 files changed, 2 insertions, 16 deletions
diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index 329771559cbb..8b3b46b7b0f2 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -44,22 +44,8 @@ extern void __init dump_numa_cpu_topology(void);
extern int sysfs_add_device_to_node(struct device *dev, int nid);
extern void sysfs_remove_device_from_node(struct device *dev, int nid);
-static inline int early_cpu_to_node(int cpu)
- int nid;
- nid = numa_cpu_lookup_table[cpu];
- /*
- * Fall back to node 0 if nid is unset (it should be, except bugs).
- * This allows callers to safely do NODE_DATA(early_cpu_to_node(cpu)).
- */
- return (nid < 0) ? 0 : nid;
-static inline int early_cpu_to_node(int cpu) { return 0; }
static inline void dump_numa_cpu_topology(void) {}
static inline int sysfs_add_device_to_node(struct device *dev, int nid)
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index fe6e800c1357..a20823210ac0 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -751,7 +751,7 @@ void __init setup_arch(char **cmdline_p)
static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
- return __alloc_bootmem_node(NODE_DATA(early_cpu_to_node(cpu)), size, align,
+ return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
@@ -762,7 +762,7 @@ static void __init pcpu_fc_free(void *ptr, size_t size)
static int pcpu_cpu_distance(unsigned int from, unsigned int to)
- if (early_cpu_to_node(from) == early_cpu_to_node(to))
+ if (cpu_to_node(from) == cpu_to_node(to))