Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On Fri, 12 Mar 2021 09:18:39 -0300 Daniel Henrique Barboza wrote: > > > On 3/12/21 6:53 AM, Cédric Le Goater wrote: > > On 3/12/21 2:55 AM, David Gibson wrote: > >> On Tue, 9 Mar 2021 18:26:35 +0100 > >> Cédric Le Goater wrote: > >> > >>> On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: > > > On 3/9/21 12:33 PM, Cédric Le Goater wrote: > > On 3/8/21 6:13 PM, Greg Kurz wrote: > >> On Wed, 3 Mar 2021 18:48:50 +0100 > >> Cédric Le Goater wrote: > >> > >>> The 'chip_id' field of the XIVE CPU structure is used to choose a > >>> target for a source located on the same chip when possible. This field > >>> is assigned on the PowerNV platform using the "ibm,chip-id" property > >>> on pSeries under KVM when NUMA nodes are defined but it is undefined > >> > >> This sentence seems to have a syntax problem... like it is missing an > >> 'and' before 'on pSeries'. > > > > ah yes, or simply a comma. > > > >>> under PowerVM. The XIVE source structure has a similar field > >>> 'src_chip' which is only assigned on the PowerNV platform. > >>> > >>> cpu_to_node() returns a compatible value on all platforms, 0 being the > >>> default node. It will also give us the opportunity to set the affinity > >>> of a source on pSeries when we can localize them. > >>> > >> > >> IIUC this relies on the fact that the NUMA node id is == to chip id > >> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable > >> with this change. > > > > Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall > > H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel > > in Cc:) > >>> [...] > > > > On PowerNV, Linux uses "ibm,associativity" property of the CPU to find > > the node id. This value is built from the chip id in OPAL, so the > > value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" > > property are unlikely to be different. > > > > cpu_to_node(cpu) is used in many places to allocate the structures > > locally to the owning node. XIVE is not an exception (see below in the > > same patch), it is better to be consistent and get the same information > > (node id) using the same routine. > > > > > > In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : > > LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot > > unifies the controllers of the system to only expose one the OS. This > > is problematic and should be changed but it's another topic. > > > > > >> On the other hand, you have the pSeries case under PowerVM that > >> doesn't xc->chip_id, which isn't passed to any hcall AFAICT. > > > > yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning > > under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid > > chip id. > > > > QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not > > always correct btw) > > > If you have a way to reliably reproduce this, let me know and I'll fix it > up in QEMU. > >>> > >>> with : > >>> > >>> -smp 4,cores=1,maxcpus=8 -object > >>> memory-backend-ram,id=ram-node0,size=2G -numa > >>> node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object > >>> memory-backend-ram,id=ram-node1,size=2G -numa > >>> node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 > >>> > >>> # dmesg | grep numa > >>> [0.013106] numa: Node 0 CPUs: 0-1 > >>> [0.013136] numa: Node 1 CPUs: 2-3 > >>> > >>> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id > >>> ibm,chip-id = <0x01>; > >>> ibm,chip-id = <0x02>; > >>> ibm,chip-id = <0x00>; > >>> ibm,chip-id = <0x03>; > >>> > >>> with : > >>> > >>>-smp 4,cores=4,maxcpus=8,threads=1 -object > >>> memory-backend-ram,id=ram-node0,size=2G -numa > >>> node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object > >>> memory-backend-ram,id=ram-node1,size=2G -numa > >>> node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 > >>> > >>> # dmesg | grep numa > >>> [0.013106] numa: Node 0 CPUs: 0-1 > >>> [0.013136] numa: Node 1 CPUs: 2-3 > >>> > >>> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id > >>> ibm,chip-id = <0x00>; > >>> ibm,chip-id = <0x00>; > >>> ibm,chip-id = <0x00>; > >>> ibm,chip-id = <0x00>; > >>> > >>> I think we should simply remove "ibm,chip-id" since it's not used and > >>> not in the PAPR spec. > >> > >> As I mentioned to Daniel on our call this morning, oddly it *does* > >> appear to be used in the RHEL kernel, even though that's 4.18 based. > >> This patch seems to have caused a minor regression; not in the > >> identification of NUMA nodes, but in the number of sockets shown be > >> lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 > >> for more information. > >
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/12/21 1:18 PM, Daniel Henrique Barboza wrote: > > > On 3/12/21 6:53 AM, Cédric Le Goater wrote: >> On 3/12/21 2:55 AM, David Gibson wrote: >>> On Tue, 9 Mar 2021 18:26:35 +0100 >>> Cédric Le Goater wrote: >>> On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: > > > On 3/9/21 12:33 PM, Cédric Le Goater wrote: >> On 3/8/21 6:13 PM, Greg Kurz wrote: >>> On Wed, 3 Mar 2021 18:48:50 +0100 >>> Cédric Le Goater wrote: >>> The 'chip_id' field of the XIVE CPU structure is used to choose a target for a source located on the same chip when possible. This field is assigned on the PowerNV platform using the "ibm,chip-id" property on pSeries under KVM when NUMA nodes are defined but it is undefined >>> >>> This sentence seems to have a syntax problem... like it is missing an >>> 'and' before 'on pSeries'. >> >> ah yes, or simply a comma. >> under PowerVM. The XIVE source structure has a similar field 'src_chip' which is only assigned on the PowerNV platform. cpu_to_node() returns a compatible value on all platforms, 0 being the default node. It will also give us the opportunity to set the affinity of a source on pSeries when we can localize them. >>> >>> IIUC this relies on the fact that the NUMA node id is == to chip id >>> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable >>> with this change. >> >> Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall >> H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel >> in Cc:) [...] >> >> On PowerNV, Linux uses "ibm,associativity" property of the CPU to find >> the node id. This value is built from the chip id in OPAL, so the >> value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" >> property are unlikely to be different. >> >> cpu_to_node(cpu) is used in many places to allocate the structures >> locally to the owning node. XIVE is not an exception (see below in the >> same patch), it is better to be consistent and get the same information >> (node id) using the same routine. >> >> >> In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : >> LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot >> unifies the controllers of the system to only expose one the OS. This >> is problematic and should be changed but it's another topic. >> >> >>> On the other hand, you have the pSeries case under PowerVM that >>> doesn't xc->chip_id, which isn't passed to any hcall AFAICT. >> >> yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning >> under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid >> chip id. >> >> QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not >> always correct btw) > > > If you have a way to reliably reproduce this, let me know and I'll fix it > up in QEMU. with : -smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [ 0.013106] numa: Node 0 CPUs: 0-1 [ 0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x01>; ibm,chip-id = <0x02>; ibm,chip-id = <0x00>; ibm,chip-id = <0x03>; with : -smp 4,cores=4,maxcpus=8,threads=1 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [ 0.013106] numa: Node 0 CPUs: 0-1 [ 0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; I think we should simply remove "ibm,chip-id" since it's not used and not in the PAPR spec. >>> >>> As I mentioned to Daniel on our call this morning, oddly it *does* >>> appear to be used in the RHEL kernel, even though that's 4.18 based. >>> This patch seems to have caused a minor regression; not in the >>> identification of NUMA nodes, but in the number of sockets shown be >>> lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 >>> for more information. >> >> Yes. The property "ibm,chip-id" is wrongly calculated in QEMU. If we >> remove it, we get with 4.18.0-295.el8.ppc64le or 5.12.0-rc2 : >> >>
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/12/21 6:53 AM, Cédric Le Goater wrote: On 3/12/21 2:55 AM, David Gibson wrote: On Tue, 9 Mar 2021 18:26:35 +0100 Cédric Le Goater wrote: On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: On 3/9/21 12:33 PM, Cédric Le Goater wrote: On 3/8/21 6:13 PM, Greg Kurz wrote: On Wed, 3 Mar 2021 18:48:50 +0100 Cédric Le Goater wrote: The 'chip_id' field of the XIVE CPU structure is used to choose a target for a source located on the same chip when possible. This field is assigned on the PowerNV platform using the "ibm,chip-id" property on pSeries under KVM when NUMA nodes are defined but it is undefined This sentence seems to have a syntax problem... like it is missing an 'and' before 'on pSeries'. ah yes, or simply a comma. under PowerVM. The XIVE source structure has a similar field 'src_chip' which is only assigned on the PowerNV platform. cpu_to_node() returns a compatible value on all platforms, 0 being the default node. It will also give us the opportunity to set the affinity of a source on pSeries when we can localize them. IIUC this relies on the fact that the NUMA node id is == to chip id on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable with this change. Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel in Cc:) [...] On PowerNV, Linux uses "ibm,associativity" property of the CPU to find the node id. This value is built from the chip id in OPAL, so the value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" property are unlikely to be different. cpu_to_node(cpu) is used in many places to allocate the structures locally to the owning node. XIVE is not an exception (see below in the same patch), it is better to be consistent and get the same information (node id) using the same routine. In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot unifies the controllers of the system to only expose one the OS. This is problematic and should be changed but it's another topic. On the other hand, you have the pSeries case under PowerVM that doesn't xc->chip_id, which isn't passed to any hcall AFAICT. yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid chip id. QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not always correct btw) If you have a way to reliably reproduce this, let me know and I'll fix it up in QEMU. with : -smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [0.013106] numa: Node 0 CPUs: 0-1 [0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x01>; ibm,chip-id = <0x02>; ibm,chip-id = <0x00>; ibm,chip-id = <0x03>; with : -smp 4,cores=4,maxcpus=8,threads=1 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [0.013106] numa: Node 0 CPUs: 0-1 [0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; I think we should simply remove "ibm,chip-id" since it's not used and not in the PAPR spec. As I mentioned to Daniel on our call this morning, oddly it *does* appear to be used in the RHEL kernel, even though that's 4.18 based. This patch seems to have caused a minor regression; not in the identification of NUMA nodes, but in the number of sockets shown be lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 for more information. Yes. The property "ibm,chip-id" is wrongly calculated in QEMU. If we remove it, we get with 4.18.0-295.el8.ppc64le or 5.12.0-rc2 : [root@localhost ~]# lscpu Architecture:ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 4 Core(s) per socket: 16 Socket(s): 2 NUMA node(s):2 Model: 2.2 (pvr 004e 1202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: KVM Virtualization type: para L1d cache: 32K L1i cache: 32K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 [root@localhost ~]# grep . /sys/devices/system/cpu/*/topology/physical_package_id
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/12/21 2:55 AM, David Gibson wrote: > On Tue, 9 Mar 2021 18:26:35 +0100 > Cédric Le Goater wrote: > >> On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: >>> >>> >>> On 3/9/21 12:33 PM, Cédric Le Goater wrote: On 3/8/21 6:13 PM, Greg Kurz wrote: > On Wed, 3 Mar 2021 18:48:50 +0100 > Cédric Le Goater wrote: > >> The 'chip_id' field of the XIVE CPU structure is used to choose a >> target for a source located on the same chip when possible. This field >> is assigned on the PowerNV platform using the "ibm,chip-id" property >> on pSeries under KVM when NUMA nodes are defined but it is undefined > > This sentence seems to have a syntax problem... like it is missing an > 'and' before 'on pSeries'. ah yes, or simply a comma. >> under PowerVM. The XIVE source structure has a similar field >> 'src_chip' which is only assigned on the PowerNV platform. >> >> cpu_to_node() returns a compatible value on all platforms, 0 being the >> default node. It will also give us the opportunity to set the affinity >> of a source on pSeries when we can localize them. >> > > IIUC this relies on the fact that the NUMA node id is == to chip id > on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable > with this change. Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel in Cc:) >> [...] On PowerNV, Linux uses "ibm,associativity" property of the CPU to find the node id. This value is built from the chip id in OPAL, so the value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" property are unlikely to be different. cpu_to_node(cpu) is used in many places to allocate the structures locally to the owning node. XIVE is not an exception (see below in the same patch), it is better to be consistent and get the same information (node id) using the same routine. In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot unifies the controllers of the system to only expose one the OS. This is problematic and should be changed but it's another topic. > On the other hand, you have the pSeries case under PowerVM that > doesn't xc->chip_id, which isn't passed to any hcall AFAICT. yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid chip id. QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not always correct btw) >>> >>> >>> If you have a way to reliably reproduce this, let me know and I'll fix it >>> up in QEMU. >> >> with : >> >>-smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G >> -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object >> memory-backend-ram,id=ram-node1,size=2G -numa >> node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 >> >> # dmesg | grep numa >> [0.013106] numa: Node 0 CPUs: 0-1 >> [0.013136] numa: Node 1 CPUs: 2-3 >> >> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id >> ibm,chip-id = <0x01>; >> ibm,chip-id = <0x02>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x03>; >> >> with : >> >> -smp 4,cores=4,maxcpus=8,threads=1 -object >> memory-backend-ram,id=ram-node0,size=2G -numa >> node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object >> memory-backend-ram,id=ram-node1,size=2G -numa >> node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 >> >> # dmesg | grep numa >> [0.013106] numa: Node 0 CPUs: 0-1 >> [0.013136] numa: Node 1 CPUs: 2-3 >> >> # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> ibm,chip-id = <0x00>; >> >> I think we should simply remove "ibm,chip-id" since it's not used and >> not in the PAPR spec. > > As I mentioned to Daniel on our call this morning, oddly it *does* > appear to be used in the RHEL kernel, even though that's 4.18 based. > This patch seems to have caused a minor regression; not in the > identification of NUMA nodes, but in the number of sockets shown be > lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 > for more information. Yes. The property "ibm,chip-id" is wrongly calculated in QEMU. If we remove it, we get with 4.18.0-295.el8.ppc64le or 5.12.0-rc2 : [root@localhost ~]# lscpu Architecture:ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 4 Core(s) per socket: 16 Socket(s): 2 NUMA node(s):2 Model: 2.2 (pvr 004e
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On Tue, 9 Mar 2021 18:26:35 +0100 Cédric Le Goater wrote: > On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: > > > > > > On 3/9/21 12:33 PM, Cédric Le Goater wrote: > >> On 3/8/21 6:13 PM, Greg Kurz wrote: > >>> On Wed, 3 Mar 2021 18:48:50 +0100 > >>> Cédric Le Goater wrote: > >>> > The 'chip_id' field of the XIVE CPU structure is used to choose a > target for a source located on the same chip when possible. This field > is assigned on the PowerNV platform using the "ibm,chip-id" property > on pSeries under KVM when NUMA nodes are defined but it is undefined > >>> > >>> This sentence seems to have a syntax problem... like it is missing an > >>> 'and' before 'on pSeries'. > >> > >> ah yes, or simply a comma. > >> > under PowerVM. The XIVE source structure has a similar field > 'src_chip' which is only assigned on the PowerNV platform. > > cpu_to_node() returns a compatible value on all platforms, 0 being the > default node. It will also give us the opportunity to set the affinity > of a source on pSeries when we can localize them. > > >>> > >>> IIUC this relies on the fact that the NUMA node id is == to chip id > >>> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable > >>> with this change. > >> > >> Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall > >> H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel > >> in Cc:) > [...] > >> > >> On PowerNV, Linux uses "ibm,associativity" property of the CPU to find > >> the node id. This value is built from the chip id in OPAL, so the > >> value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" > >> property are unlikely to be different. > >> > >> cpu_to_node(cpu) is used in many places to allocate the structures > >> locally to the owning node. XIVE is not an exception (see below in the > >> same patch), it is better to be consistent and get the same information > >> (node id) using the same routine. > >> > >> > >> In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : > >> LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot > >> unifies the controllers of the system to only expose one the OS. This > >> is problematic and should be changed but it's another topic. > >> > >> > >>> On the other hand, you have the pSeries case under PowerVM that > >>> doesn't xc->chip_id, which isn't passed to any hcall AFAICT. > >> > >> yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning > >> under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid > >> chip id. > >> > >> QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not > >> always correct btw) > > > > > > If you have a way to reliably reproduce this, let me know and I'll fix it > > up in QEMU. > > with : > >-smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G > -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object > memory-backend-ram,id=ram-node1,size=2G -numa > node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 > > # dmesg | grep numa > [0.013106] numa: Node 0 CPUs: 0-1 > [0.013136] numa: Node 1 CPUs: 2-3 > > # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id > ibm,chip-id = <0x01>; > ibm,chip-id = <0x02>; > ibm,chip-id = <0x00>; > ibm,chip-id = <0x03>; > > with : > > -smp 4,cores=4,maxcpus=8,threads=1 -object > memory-backend-ram,id=ram-node0,size=2G -numa > node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object > memory-backend-ram,id=ram-node1,size=2G -numa > node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 > > # dmesg | grep numa > [0.013106] numa: Node 0 CPUs: 0-1 > [0.013136] numa: Node 1 CPUs: 2-3 > > # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id > ibm,chip-id = <0x00>; > ibm,chip-id = <0x00>; > ibm,chip-id = <0x00>; > ibm,chip-id = <0x00>; > > I think we should simply remove "ibm,chip-id" since it's not used and > not in the PAPR spec. As I mentioned to Daniel on our call this morning, oddly it *does* appear to be used in the RHEL kernel, even though that's 4.18 based. This patch seems to have caused a minor regression; not in the identification of NUMA nodes, but in the number of sockets shown be lscpu, etc. See https://bugzilla.redhat.com/show_bug.cgi?id=1934421 for more information. Since the value was used by some PAPR kernels - even if they shouldn't have - I think we should only remove this for newer machine types. We also need to check what we're not supplying that the guest kernel is showing a different number of sockets than specified on the qemu command line. > > Thanks, > > C. > > > > [...] > [...] > [...] > [...] > [...] > [...] > [...] > [...] > [...] > -- David Gibson Principal Software Engineer, Virtualization, Red Hat
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/9/21 12:33 PM, Cédric Le Goater wrote:
On 3/8/21 6:13 PM, Greg Kurz wrote:
On Wed, 3 Mar 2021 18:48:50 +0100
Cédric Le Goater wrote:
The 'chip_id' field of the XIVE CPU structure is used to choose a
target for a source located on the same chip when possible. This field
is assigned on the PowerNV platform using the "ibm,chip-id" property
on pSeries under KVM when NUMA nodes are defined but it is undefined
This sentence seems to have a syntax problem... like it is missing an
'and' before 'on pSeries'.
ah yes, or simply a comma.
under PowerVM. The XIVE source structure has a similar field
'src_chip' which is only assigned on the PowerNV platform.
cpu_to_node() returns a compatible value on all platforms, 0 being the
default node. It will also give us the opportunity to set the affinity
of a source on pSeries when we can localize them.
IIUC this relies on the fact that the NUMA node id is == to chip id
on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable
with this change.
Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall
H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel
in Cc:)
That's correct. H_HOME_NODE_ASSOCIATIVITY returns not only the node_id, but
a list with the ibm,associativity domains of the CPU that "proc-no" (processor
identifier) is mapped to inside QEMU.
node_id in this case, considering that we're working with a reference-points
of size 4, is the 4th element of the returned list. The last element is
"procno" itself.
On PowerNV, Linux uses "ibm,associativity" property of the CPU to find
the node id. This value is built from the chip id in OPAL, so the
value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id"
property are unlikely to be different.
cpu_to_node(cpu) is used in many places to allocate the structures
locally to the owning node. XIVE is not an exception (see below in the
same patch), it is better to be consistent and get the same information
(node id) using the same routine.
In Linux, "ibm,chip-id" is only used in low level PowerNV drivers :
LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot
unifies the controllers of the system to only expose one the OS. This
is problematic and should be changed but it's another topic.
On the other hand, you have the pSeries case under PowerVM that
doesn't xc->chip_id, which isn't passed to any hcall AFAICT.
yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning
under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid
chip id.
QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not
always correct btw)
If you have a way to reliably reproduce this, let me know and I'll fix it
up in QEMU.
Thanks,
DHB
It looks like the chip id is only used for localization purpose in
this case, right ?
Yes and PAPR sources are not localized. So it's not used. MSI sources
could be if we rewrote the MSI driver.
In this case, what about doing this change for pSeries only,
somewhere in spapr.c ?
The IPI code is common to all platforms and all have the same issue.
I rather not.
Thanks,
C.
Signed-off-by: Cédric Le Goater
---
arch/powerpc/sysdev/xive/common.c | 7 +--
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/powerpc/sysdev/xive/common.c
b/arch/powerpc/sysdev/xive/common.c
index 595310e056f4..b8e456da28aa 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1335,16 +1335,11 @@ static int xive_prepare_cpu(unsigned int cpu)
xc = per_cpu(xive_cpu, cpu);
if (!xc) {
- struct device_node *np;
-
xc = kzalloc_node(sizeof(struct xive_cpu),
GFP_KERNEL, cpu_to_node(cpu));
if (!xc)
return -ENOMEM;
- np = of_get_cpu_node(cpu, NULL);
- if (np)
- xc->chip_id = of_get_ibm_chip_id(np);
- of_node_put(np);
+ xc->chip_id = cpu_to_node(cpu);
xc->hw_ipi = XIVE_BAD_IRQ;
per_cpu(xive_cpu, cpu) = xc;
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/9/21 6:08 PM, Daniel Henrique Barboza wrote: > > > On 3/9/21 12:33 PM, Cédric Le Goater wrote: >> On 3/8/21 6:13 PM, Greg Kurz wrote: >>> On Wed, 3 Mar 2021 18:48:50 +0100 >>> Cédric Le Goater wrote: >>> The 'chip_id' field of the XIVE CPU structure is used to choose a target for a source located on the same chip when possible. This field is assigned on the PowerNV platform using the "ibm,chip-id" property on pSeries under KVM when NUMA nodes are defined but it is undefined >>> >>> This sentence seems to have a syntax problem... like it is missing an >>> 'and' before 'on pSeries'. >> >> ah yes, or simply a comma. >> under PowerVM. The XIVE source structure has a similar field 'src_chip' which is only assigned on the PowerNV platform. cpu_to_node() returns a compatible value on all platforms, 0 being the default node. It will also give us the opportunity to set the affinity of a source on pSeries when we can localize them. >>> >>> IIUC this relies on the fact that the NUMA node id is == to chip id >>> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable >>> with this change. >> >> Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall >> H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel >> in Cc:) > > That's correct. H_HOME_NODE_ASSOCIATIVITY returns not only the node_id, but > a list with the ibm,associativity domains of the CPU that "proc-no" (processor > identifier) is mapped to inside QEMU. > > node_id in this case, considering that we're working with a reference-points > of size 4, is the 4th element of the returned list. The last element is > "procno" itself. > > >> >> On PowerNV, Linux uses "ibm,associativity" property of the CPU to find >> the node id. This value is built from the chip id in OPAL, so the >> value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id" >> property are unlikely to be different. >> >> cpu_to_node(cpu) is used in many places to allocate the structures >> locally to the owning node. XIVE is not an exception (see below in the >> same patch), it is better to be consistent and get the same information >> (node id) using the same routine. >> >> >> In Linux, "ibm,chip-id" is only used in low level PowerNV drivers : >> LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot >> unifies the controllers of the system to only expose one the OS. This >> is problematic and should be changed but it's another topic. >> >> >>> On the other hand, you have the pSeries case under PowerVM that >>> doesn't xc->chip_id, which isn't passed to any hcall AFAICT. >> >> yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning >> under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid >> chip id. >> >> QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not >> always correct btw) > > > If you have a way to reliably reproduce this, let me know and I'll fix it > up in QEMU. with : -smp 4,cores=1,maxcpus=8 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [0.013106] numa: Node 0 CPUs: 0-1 [0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x01>; ibm,chip-id = <0x02>; ibm,chip-id = <0x00>; ibm,chip-id = <0x03>; with : -smp 4,cores=4,maxcpus=8,threads=1 -object memory-backend-ram,id=ram-node0,size=2G -numa node,nodeid=0,cpus=0-1,cpus=4-5,memdev=ram-node0 -object memory-backend-ram,id=ram-node1,size=2G -numa node,nodeid=1,cpus=2-3,cpus=6-7,memdev=ram-node1 # dmesg | grep numa [0.013106] numa: Node 0 CPUs: 0-1 [0.013136] numa: Node 1 CPUs: 2-3 # dtc -I fs /proc/device-tree/cpus/ -f | grep ibm,chip-id ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; ibm,chip-id = <0x00>; I think we should simply remove "ibm,chip-id" since it's not used and not in the PAPR spec. Thanks, C. > > Thanks, > > > DHB > > >> >>> It looks like the chip id is only used for localization purpose in >>> this case, right ? >> >> Yes and PAPR sources are not localized. So it's not used. MSI sources >> could be if we rewrote the MSI driver. >> >>> In this case, what about doing this change for pSeries only, >>> somewhere in spapr.c ? >> >> The IPI code is common to all platforms and all have the same issue. >> I rather not. >> >> Thanks, >> >> C. >> Signed-off-by: Cédric Le Goater --- arch/powerpc/sysdev/xive/common.c | 7 +-- 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c index 595310e056f4..b8e456da28aa
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On 3/8/21 6:13 PM, Greg Kurz wrote:
> On Wed, 3 Mar 2021 18:48:50 +0100
> Cédric Le Goater wrote:
>
>> The 'chip_id' field of the XIVE CPU structure is used to choose a
>> target for a source located on the same chip when possible. This field
>> is assigned on the PowerNV platform using the "ibm,chip-id" property
>> on pSeries under KVM when NUMA nodes are defined but it is undefined
>
> This sentence seems to have a syntax problem... like it is missing an
> 'and' before 'on pSeries'.
ah yes, or simply a comma.
>> under PowerVM. The XIVE source structure has a similar field
>> 'src_chip' which is only assigned on the PowerNV platform.
>>
>> cpu_to_node() returns a compatible value on all platforms, 0 being the
>> default node. It will also give us the opportunity to set the affinity
>> of a source on pSeries when we can localize them.
>>
>
> IIUC this relies on the fact that the NUMA node id is == to chip id
> on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable
> with this change.
Linux sets the NUMA node in numa_setup_cpu(). On pseries, the hcall
H_HOME_NODE_ASSOCIATIVITY returns the node id if I am correct (Daniel
in Cc:)
On PowerNV, Linux uses "ibm,associativity" property of the CPU to find
the node id. This value is built from the chip id in OPAL, so the
value returned by cpu_to_node(cpu) and the value of the "ibm,chip-id"
property are unlikely to be different.
cpu_to_node(cpu) is used in many places to allocate the structures
locally to the owning node. XIVE is not an exception (see below in the
same patch), it is better to be consistent and get the same information
(node id) using the same routine.
In Linux, "ibm,chip-id" is only used in low level PowerNV drivers :
LPC, XSCOM, RNG, VAS, NX. XIVE should be in that list also but skiboot
unifies the controllers of the system to only expose one the OS. This
is problematic and should be changed but it's another topic.
> On the other hand, you have the pSeries case under PowerVM that
> doesn't xc->chip_id, which isn't passed to any hcall AFAICT.
yes "ibm,chip-id" is an OPAL concept unfortunately and it has no meaning
under PAPR. xc->chip_id on pseries (PowerVM) will contains an invalid
chip id.
QEMU/KVM exposes "ibm,chip-id" but it's not used. (its value is not
always correct btw)
> It looks like the chip id is only used for localization purpose in
> this case, right ?
Yes and PAPR sources are not localized. So it's not used. MSI sources
could be if we rewrote the MSI driver.
> In this case, what about doing this change for pSeries only,
> somewhere in spapr.c ?
The IPI code is common to all platforms and all have the same issue.
I rather not.
Thanks,
C.
>> Signed-off-by: Cédric Le Goater
>> ---
>> arch/powerpc/sysdev/xive/common.c | 7 +--
>> 1 file changed, 1 insertion(+), 6 deletions(-)
>>
>> diff --git a/arch/powerpc/sysdev/xive/common.c
>> b/arch/powerpc/sysdev/xive/common.c
>> index 595310e056f4..b8e456da28aa 100644
>> --- a/arch/powerpc/sysdev/xive/common.c
>> +++ b/arch/powerpc/sysdev/xive/common.c
>> @@ -1335,16 +1335,11 @@ static int xive_prepare_cpu(unsigned int cpu)
>>
>> xc = per_cpu(xive_cpu, cpu);
>> if (!xc) {
>> -struct device_node *np;
>> -
>> xc = kzalloc_node(sizeof(struct xive_cpu),
>>GFP_KERNEL, cpu_to_node(cpu));
>> if (!xc)
>> return -ENOMEM;
>> -np = of_get_cpu_node(cpu, NULL);
>> -if (np)
>> -xc->chip_id = of_get_ibm_chip_id(np);
>> -of_node_put(np);
>> +xc->chip_id = cpu_to_node(cpu);
>> xc->hw_ipi = XIVE_BAD_IRQ;
>>
>> per_cpu(xive_cpu, cpu) = xc;
>
Re: [PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm,chip-id property
On Wed, 3 Mar 2021 18:48:50 +0100
Cédric Le Goater wrote:
> The 'chip_id' field of the XIVE CPU structure is used to choose a
> target for a source located on the same chip when possible. This field
> is assigned on the PowerNV platform using the "ibm,chip-id" property
> on pSeries under KVM when NUMA nodes are defined but it is undefined
This sentence seems to have a syntax problem... like it is missing an
'and' before 'on pSeries'.
> under PowerVM. The XIVE source structure has a similar field
> 'src_chip' which is only assigned on the PowerNV platform.
>
> cpu_to_node() returns a compatible value on all platforms, 0 being the
> default node. It will also give us the opportunity to set the affinity
> of a source on pSeries when we can localize them.
>
IIUC this relies on the fact that the NUMA node id is == to chip id
on PowerNV, i.e. xc->chip_id which is passed to OPAL remain stable
with this change.
On the other hand, you have the pSeries case under PowerVM that
doesn't xc->chip_id, which isn't passed to any hcall AFAICT. It
looks like the chip id is only used for localization purpose in
this case, right ?
In this case, what about doing this change for pSeries only,
somewhere in spapr.c ?
> Signed-off-by: Cédric Le Goater
> ---
> arch/powerpc/sysdev/xive/common.c | 7 +--
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/sysdev/xive/common.c
> b/arch/powerpc/sysdev/xive/common.c
> index 595310e056f4..b8e456da28aa 100644
> --- a/arch/powerpc/sysdev/xive/common.c
> +++ b/arch/powerpc/sysdev/xive/common.c
> @@ -1335,16 +1335,11 @@ static int xive_prepare_cpu(unsigned int cpu)
>
> xc = per_cpu(xive_cpu, cpu);
> if (!xc) {
> - struct device_node *np;
> -
> xc = kzalloc_node(sizeof(struct xive_cpu),
> GFP_KERNEL, cpu_to_node(cpu));
> if (!xc)
> return -ENOMEM;
> - np = of_get_cpu_node(cpu, NULL);
> - if (np)
> - xc->chip_id = of_get_ibm_chip_id(np);
> - of_node_put(np);
> + xc->chip_id = cpu_to_node(cpu);
> xc->hw_ipi = XIVE_BAD_IRQ;
>
> per_cpu(xive_cpu, cpu) = xc;
[PATCH v2 1/8] powerpc/xive: Use cpu_to_node() instead of ibm, chip-id property
The 'chip_id' field of the XIVE CPU structure is used to choose a
target for a source located on the same chip when possible. This field
is assigned on the PowerNV platform using the "ibm,chip-id" property
on pSeries under KVM when NUMA nodes are defined but it is undefined
under PowerVM. The XIVE source structure has a similar field
'src_chip' which is only assigned on the PowerNV platform.
cpu_to_node() returns a compatible value on all platforms, 0 being the
default node. It will also give us the opportunity to set the affinity
of a source on pSeries when we can localize them.
Signed-off-by: Cédric Le Goater
---
arch/powerpc/sysdev/xive/common.c | 7 +--
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/powerpc/sysdev/xive/common.c
b/arch/powerpc/sysdev/xive/common.c
index 595310e056f4..b8e456da28aa 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1335,16 +1335,11 @@ static int xive_prepare_cpu(unsigned int cpu)
xc = per_cpu(xive_cpu, cpu);
if (!xc) {
- struct device_node *np;
-
xc = kzalloc_node(sizeof(struct xive_cpu),
GFP_KERNEL, cpu_to_node(cpu));
if (!xc)
return -ENOMEM;
- np = of_get_cpu_node(cpu, NULL);
- if (np)
- xc->chip_id = of_get_ibm_chip_id(np);
- of_node_put(np);
+ xc->chip_id = cpu_to_node(cpu);
xc->hw_ipi = XIVE_BAD_IRQ;
per_cpu(xive_cpu, cpu) = xc;
--
2.26.2
