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| author | Nathan Fontenot <nfont@linux.vnet.ibm.com> | 2018-10-29 13:43:36 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-05 22:33:13 +0200 |
| commit | 06af7dda05b33fe7b37bdf95b87e944b2e2de608 (patch) | |
| tree | fff68656c928feeb418515a2ed587c18f5319a7f /arch/powerpc/platforms | |
| parent | 57f03bbd42363b8e6287acc4116c676c99807080 (diff) | |
powerpc/pseries: Perform full re-add of CPU for topology update post-migration
[ Upstream commit 81b61324922c67f73813d8a9c175f3c153f6a1c6 ]
On pseries systems, performing a partition migration can result in
altering the nodes a CPU is assigned to on the destination system. For
exampl, pre-migration on the source system CPUs are in node 1 and 3,
post-migration on the destination system CPUs are in nodes 2 and 3.
Handling the node change for a CPU can cause corruption in the slab
cache if we hit a timing where a CPUs node is changed while cache_reap()
is invoked. The corruption occurs because the slab cache code appears
to rely on the CPU and slab cache pages being on the same node.
The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c
does not prevent us from hitting this scenario.
Changing the device tree property update notification handler that
recognizes an affinity change for a CPU to do a full DLPAR remove and
add of the CPU instead of dynamically changing its node resolves this
issue.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com>
Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/powerpc/platforms')
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 6ef77caf7bcf..1d3f9313c02f 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -802,6 +802,25 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add) return rc; } +int dlpar_cpu_readd(int cpu) +{ + struct device_node *dn; + struct device *dev; + u32 drc_index; + int rc; + + dev = get_cpu_device(cpu); + dn = dev->of_node; + + rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index); + + rc = dlpar_cpu_remove_by_index(drc_index); + if (!rc) + rc = dlpar_cpu_add(drc_index); + + return rc; +} + int dlpar_cpu(struct pseries_hp_errorlog *hp_elog) { u32 count, drc_index; |