| Message ID | 20200428093836.27190-3-srikar@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Offline memoryless cpuless node 0 | expand |
Hello Srikar, On Tue, Apr 28, 2020 at 03:08:35PM +0530, Srikar Dronamraju wrote: > Node id queried from the static device tree may not > be correct. For example: it may always show 0 on a shared processor. > Hence prefer the node id queried from vphn and fallback on the device tree > based node id if vphn query fails. > > Cc: linuxppc-dev@lists.ozlabs.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Cc: Michal Hocko <mhocko@suse.com> > Cc: Mel Gorman <mgorman@suse.de> > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: "Kirill A. Shutemov" <kirill@shutemov.name> > Cc: Christopher Lameter <cl@linux.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > --- > Changelog v1:->v2: > - Rebased to v5.7-rc3 > > arch/powerpc/mm/numa.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c > index b3615b7fdbdf..281531340230 100644 > --- a/arch/powerpc/mm/numa.c > +++ b/arch/powerpc/mm/numa.c > @@ -719,20 +719,20 @@ static int __init parse_numa_properties(void) > */ > for_each_present_cpu(i) { > struct device_node *cpu; > - int nid; > - > - cpu = of_get_cpu_node(i, NULL); > - BUG_ON(!cpu); > - nid = of_node_to_nid_single(cpu); > - of_node_put(cpu); > + int nid = vphn_get_nid(i); > > /* > * Don't fall back to default_nid yet -- we will plug > * cpus into nodes once the memory scan has discovered > * the topology. > */ > - if (nid < 0) > - continue; > + if (nid == NUMA_NO_NODE) { > + cpu = of_get_cpu_node(i, NULL); > + if (cpu) { Why are we not retaining the BUG_ON(!cpu) assert here ? > + nid = of_node_to_nid_single(cpu); > + of_node_put(cpu); > + } > + } Is it possible at this point that both vphn_get_nid(i) and of_node_to_nid_single(cpu) returns NUMA_NO_NODE ? If so, should we still call node_set_online() below ? > node_set_online(nid); > } > > -- > 2.20.1 > -- Thanks and Regards gautham.
* Gautham R Shenoy <ego@linux.vnet.ibm.com> [2020-04-29 12:22:29]: > Hello Srikar, > > > > + if (nid == NUMA_NO_NODE) { > > + cpu = of_get_cpu_node(i, NULL); > > + if (cpu) { > > Why are we not retaining the BUG_ON(!cpu) assert here ? > > > + nid = of_node_to_nid_single(cpu); > > + of_node_put(cpu); > > + } > > + } > > Is it possible at this point that both vphn_get_nid(i) and > of_node_to_nid_single(cpu) returns NUMA_NO_NODE ? If so, > should we still call node_set_online() below ? Yeah, I think It makes sense to retain the BUG_ON and if check. Will incorporate both of them in the next version. > > > > node_set_online(nid); > > } > > > > -- > > 2.20.1 > > > -- > Thanks and Regards > gautham.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index b3615b7fdbdf..281531340230 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -719,20 +719,20 @@ static int __init parse_numa_properties(void) */ for_each_present_cpu(i) { struct device_node *cpu; - int nid; - - cpu = of_get_cpu_node(i, NULL); - BUG_ON(!cpu); - nid = of_node_to_nid_single(cpu); - of_node_put(cpu); + int nid = vphn_get_nid(i); /* * Don't fall back to default_nid yet -- we will plug * cpus into nodes once the memory scan has discovered * the topology. */ - if (nid < 0) - continue; + if (nid == NUMA_NO_NODE) { + cpu = of_get_cpu_node(i, NULL); + if (cpu) { + nid = of_node_to_nid_single(cpu); + of_node_put(cpu); + } + } node_set_online(nid); }
Node id queried from the static device tree may not be correct. For example: it may always show 0 on a shared processor. Hence prefer the node id queried from vphn and fallback on the device tree based node id if vphn query fails. Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Christopher Lameter <cl@linux.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> --- Changelog v1:->v2: - Rebased to v5.7-rc3 arch/powerpc/mm/numa.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)