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authorNathan Fontenot2018-01-26 20:41:59 +0100
committerMichael Ellerman2018-02-08 13:56:10 +0100
commit1d9a090783bef19fe8cdec878620d22f05191316 (patch)
treeafb105639d72a44289bfc1111d37a6dbe915c0be /arch/powerpc/mm
parentMerge tag 'modules-for-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff)
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powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
When DLPAR removing a CPU, the unmapping of the cpu from a node in unmap_cpu_from_node() should also invalidate the CPUs entry in the numa_cpu_lookup_table. There is not a guarantee that on a subsequent DLPAR add of the CPU the associativity will be the same and thus could be in a different node. Invalidating the entry in the numa_cpu_lookup_table causes the associativity to be read from the device tree at the time of the add. The current behavior of not invalidating the CPUs entry in the numa_cpu_lookup_table can result in scenarios where the the topology layout of CPUs in the partition does not match the device tree or the topology reported by the HMC. This bug looks like it was introduced in 2004 in the commit titled "ppc64: cpu hotplug notifier for numa", which is 6b15e4e87e32 in the linux-fullhist tree. Hence tag it for all stable releases. Cc: stable@vger.kernel.org Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm')
-rw-r--r--arch/powerpc/mm/numa.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 314d19ab9385..edd8d0bc9364 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -143,11 +143,6 @@ static void reset_numa_cpu_lookup_table(void)
numa_cpu_lookup_table[cpu] = -1;
}
-static void update_numa_cpu_lookup_table(unsigned int cpu, int node)
-{
- numa_cpu_lookup_table[cpu] = node;
-}
-
static void map_cpu_to_node(int cpu, int node)
{
update_numa_cpu_lookup_table(cpu, node);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-20 00:08:10 +0200
href='#n191'>191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 
/* MTD-based superblock management
 *
 * Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved.
 * Copyright © 2001-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Written by:  David Howells <dhowells@redhat.com>
 *              David Woodhouse <dwmw2@infradead.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/mtd/super.h>
#include <linux/namei.h>
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/backing-dev.h>

/*
 * compare superblocks to see if they're equivalent
 * - they are if the underlying MTD device is the same
 */
static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
{
	struct mtd_info *mtd = _mtd;

	if (sb->s_mtd == mtd) {
		pr_debug("MTDSB: Match on device %d (\"%s\")\n",
		      mtd->index, mtd->name);
		return 1;
	}

	pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
	      sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
	return 0;
}

extern struct backing_dev_info *mtd_bdi;

/*
 * mark the superblock by the MTD device it is using
 * - set the device number to be the correct MTD block device for pesuperstence
 *   of NFS exports
 */
static int get_sb_mtd_set(struct super_block *sb, void *_mtd)
{
	struct mtd_info *mtd = _mtd;

	sb->s_mtd = mtd;
	sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
	sb->s_bdi = bdi_get(mtd_bdi);

	return 0;
}

/*
 * get a superblock on an MTD-backed filesystem
 */
static struct dentry *mount_mtd_aux(struct file_system_type *fs_type, int flags,
			  const char *dev_name, void *data,
			  struct mtd_info *mtd,
			  int (*fill_super)(struct super_block *, void *, int))
{
	struct super_block *sb;
	int ret;

	sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, flags, mtd);
	if (IS_ERR(sb))
		goto out_error;

	if (sb->s_root)
		goto already_mounted;