diff options
| author | Srikar Dronamraju <srikar@linux.vnet.ibm.com> | 2020-01-29 19:22:59 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-03-04 22:44:30 +1100 |
| commit | 413e40550c5cfdba7e062aa6350a0d2448014519 (patch) | |
| tree | f82e46295ae732e0ae8f7974a34842fd8edd9409 /arch/powerpc/mm/numa.c | |
| parent | 76b7bfb1732d139dc20a2f0c19ec32e09c8891cf (diff) | |
powerpc/numa: Use cpu node map of first sibling thread
All the sibling threads of a core have to be part of the same node.
To ensure that all the sibling threads map to the same node, always
lookup/update the cpu-to-node map of the first thread in the core.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200129135301.24739-4-srikar@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/mm/numa.c')
| -rw-r--r-- | arch/powerpc/mm/numa.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 2cb87c9a0544..518c6dbbccbe 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -467,15 +467,20 @@ static int of_drconf_to_nid_single(struct drmem_lmb *lmb) */ static int numa_setup_cpu(unsigned long lcpu) { - int nid = NUMA_NO_NODE; struct device_node *cpu; + int fcpu = cpu_first_thread_sibling(lcpu); + int nid = NUMA_NO_NODE; /* * If a valid cpu-to-node mapping is already available, use it * directly instead of querying the firmware, since it represents * the most recent mapping notified to us by the platform (eg: VPHN). + * Since cpu_to_node binding remains the same for all threads in the + * core. If a valid cpu-to-node mapping is already available, for + * the first thread in the core, use it. */ - if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) { + nid = numa_cpu_lookup_table[fcpu]; + if (nid >= 0) { map_cpu_to_node(lcpu, nid); return nid; } @@ -496,6 +501,19 @@ out_present: if (nid < 0 || !node_possible(nid)) nid = first_online_node; + /* + * Update for the first thread of the core. All threads of a core + * have to be part of the same node. This not only avoids querying + * for every other thread in the core, but always avoids a case + * where virtual node associativity change causes subsequent threads + * of a core to be associated with different nid. However if first + * thread is already online, expect it to have a valid mapping. + */ + if (fcpu != lcpu) { + WARN_ON(cpu_online(fcpu)); + map_cpu_to_node(fcpu, nid); + } + map_cpu_to_node(lcpu, nid); of_node_put(cpu); out: |