From: Stefano Stabellini <sstabellini@kernel.org>
To: Wei Chen <Wei.Chen@arm.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
"xen-devel@lists.xenproject.org"
<xen-devel@lists.xenproject.org>,
"julien@xen.org" <julien@xen.org>,
Bertrand Marquis <Bertrand.Marquis@arm.com>
Subject: RE: [PATCH 22/37] xen/arm: use NR_MEM_BANKS to override default NR_NODE_MEMBLKS
Date: Sun, 26 Sep 2021 20:25:42 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.21.2109262021200.5022@sstabellini-ThinkPad-T480s> (raw)
In-Reply-To: <DB9PR08MB685744A06D7C014DAE9BE73F9EA69@DB9PR08MB6857.eurprd08.prod.outlook.com>
[-- Attachment #1: Type: text/plain, Size: 3525 bytes --]
On Sun, 26 Sep 2021, Wei Chen wrote:
> > -----Original Message-----
> > From: Stefano Stabellini <sstabellini@kernel.org>
> > Sent: 2021年9月24日 9:35
> > To: Wei Chen <Wei.Chen@arm.com>
> > Cc: xen-devel@lists.xenproject.org; sstabellini@kernel.org; julien@xen.org;
> > Bertrand Marquis <Bertrand.Marquis@arm.com>
> > Subject: Re: [PATCH 22/37] xen/arm: use NR_MEM_BANKS to override default
> > NR_NODE_MEMBLKS
> >
> > On Thu, 23 Sep 2021, Wei Chen wrote:
> > > As a memory range described in device tree cannot be split across
> > > multiple nodes. So we define NR_NODE_MEMBLKS as NR_MEM_BANKS in
> > > arch header.
> >
> > This statement is true but what is the goal of this patch? Is it to
> > reduce code size and memory consumption?
> >
>
> No, when Julien and I discussed this in last version[1], we hadn't thought
> so deeply. We just thought a memory range described in DT cannot be split
> across multiple nodes. So NR_MEM_BANKS should be equal to NR_MEM_BANKS.
>
> https://lists.xenproject.org/archives/html/xen-devel/2021-08/msg00974.html
>
> > I am asking because NR_MEM_BANKS is 128 and
> > NR_NODE_MEMBLKS=2*MAX_NUMNODES which is 64 by default so again
> > NR_NODE_MEMBLKS is 128 before this patch.
> >
> > In other words, this patch alone doesn't make any difference; at least
> > doesn't make any difference unless CONFIG_NR_NUMA_NODES is increased.
> >
> > So, is the goal to reduce memory usage when CONFIG_NR_NUMA_NODES is
> > higher than 64?
> >
>
> I also thought about this problem when I was writing this patch.
> CONFIG_NR_NUMA_NODES is increasing, but NR_MEM_BANKS is a fixed
> value, then NR_MEM_BANKS can be smaller than CONFIG_NR_NUMA_NODES
> at one point.
>
> But I agree with Julien's suggestion, NR_MEM_BANKS and NR_NODE_MEMBLKS
> must be aware of each other. I had thought to add some ASSERT check,
> but I don't know how to do it better. So I post this patch for more
> suggestion.
OK. In that case I'd say to get rid of the previous definition of
NR_NODE_MEMBLKS as it is probably not necessary, see below.
> >
> > > And keep default NR_NODE_MEMBLKS in common header
> > > for those architectures NUMA is disabled.
> >
> > This last sentence is not accurate: on x86 NUMA is enabled and
> > NR_NODE_MEMBLKS is still defined in xen/include/xen/numa.h (there is no
> > x86 definition of it)
> >
>
> Yes.
>
> >
> > > Signed-off-by: Wei Chen <wei.chen@arm.com>
> > > ---
> > > xen/include/asm-arm/numa.h | 8 +++++++-
> > > xen/include/xen/numa.h | 2 ++
> > > 2 files changed, 9 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/xen/include/asm-arm/numa.h b/xen/include/asm-arm/numa.h
> > > index 8f1c67e3eb..21569e634b 100644
> > > --- a/xen/include/asm-arm/numa.h
> > > +++ b/xen/include/asm-arm/numa.h
> > > @@ -3,9 +3,15 @@
> > >
> > > #include <xen/mm.h>
> > >
> > > +#include <asm/setup.h>
> > > +
> > > typedef u8 nodeid_t;
> > >
> > > -#ifndef CONFIG_NUMA
> > > +#ifdef CONFIG_NUMA
> > > +
> > > +#define NR_NODE_MEMBLKS NR_MEM_BANKS
> > > +
> > > +#else
> > >
> > > /* Fake one node for now. See also node_online_map. */
> > > #define cpu_to_node(cpu) 0
> > > diff --git a/xen/include/xen/numa.h b/xen/include/xen/numa.h
> > > index 1978e2be1b..1731e1cc6b 100644
> > > --- a/xen/include/xen/numa.h
> > > +++ b/xen/include/xen/numa.h
> > > @@ -12,7 +12,9 @@
> > > #define MAX_NUMNODES 1
> > > #endif
> > >
> > > +#ifndef NR_NODE_MEMBLKS
> > > #define NR_NODE_MEMBLKS (MAX_NUMNODES*2)
> > > +#endif
This one we can remove it completely right?
next prev parent reply other threads:[~2021-09-27 3:25 UTC|newest]
Thread overview: 192+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 12:01 [PATCH 00/37] Add device tree based NUMA support to Arm Wei Chen
2021-09-23 12:02 ` [PATCH 01/37] xen/arm: Print a 64-bit number in hex from early uart Wei Chen
2021-09-23 12:02 ` [PATCH 02/37] xen: introduce a Kconfig option to configure NUMA nodes number Wei Chen
2021-09-23 23:45 ` Stefano Stabellini
2021-09-24 1:24 ` Wei Chen
2021-09-24 8:55 ` Jan Beulich
2021-09-24 10:33 ` Wei Chen
2021-09-24 10:47 ` Jan Beulich
2021-09-23 12:02 ` [PATCH 03/37] xen/x86: Initialize memnodemapsize while faking NUMA node Wei Chen
2021-09-24 8:57 ` Jan Beulich
2021-09-24 10:34 ` Wei Chen
2021-09-23 12:02 ` [PATCH 04/37] xen: introduce an arch helper for default dma zone status Wei Chen
2021-09-23 23:55 ` Stefano Stabellini
2021-09-24 1:50 ` Wei Chen
2022-01-17 16:10 ` Jan Beulich
2022-01-18 7:51 ` Wei Chen
2022-01-18 8:16 ` Jan Beulich
2022-01-18 9:20 ` Wei Chen
2022-01-18 14:16 ` Jan Beulich
2022-01-19 2:49 ` Wei Chen
2022-01-19 7:50 ` Jan Beulich
2022-01-19 8:33 ` Wei Chen
2021-09-23 12:02 ` [PATCH 05/37] xen: decouple NUMA from ACPI in Kconfig Wei Chen
2021-09-23 12:02 ` [PATCH 06/37] xen/arm: use !CONFIG_NUMA to keep fake NUMA API Wei Chen
2021-09-24 0:05 ` Stefano Stabellini
2021-09-24 10:21 ` Wei Chen
2021-09-23 12:02 ` [PATCH 07/37] xen/x86: use paddr_t for addresses in NUMA node structure Wei Chen
2021-09-24 0:11 ` Stefano Stabellini
2021-09-24 0:13 ` Stefano Stabellini
2021-09-24 3:00 ` Wei Chen
2022-01-18 15:22 ` Jan Beulich
2022-01-19 6:33 ` Wei Chen
2022-01-19 7:55 ` Jan Beulich
2022-01-19 8:36 ` Wei Chen
2021-09-23 12:02 ` [PATCH 08/37] xen/x86: add detection of discontinous node memory range Wei Chen
2021-09-24 0:25 ` Stefano Stabellini
2021-09-24 4:28 ` Wei Chen
2021-09-24 19:52 ` Stefano Stabellini
2021-09-26 10:11 ` Wei Chen
2021-09-27 3:13 ` Stefano Stabellini
2021-09-27 5:05 ` Stefano Stabellini
2021-09-27 9:50 ` Wei Chen
2021-09-27 17:19 ` Stefano Stabellini
2021-09-28 4:41 ` Wei Chen
2021-09-28 4:59 ` Stefano Stabellini
2022-01-18 16:13 ` Jan Beulich
2022-01-19 7:33 ` Wei Chen
2022-01-19 8:01 ` Jan Beulich
2022-01-19 8:24 ` Wei Chen
2021-09-23 12:02 ` [PATCH 09/37] xen/x86: introduce two helpers to access memory hotplug end Wei Chen
2021-09-24 0:29 ` Stefano Stabellini
2021-09-24 4:21 ` Wei Chen
2022-01-24 16:24 ` Jan Beulich
2022-01-26 7:53 ` Wei Chen
2021-09-23 12:02 ` [PATCH 10/37] xen/x86: use helpers to access/update mem_hotplug Wei Chen
2021-09-24 0:31 ` Stefano Stabellini
2021-09-24 4:29 ` Wei Chen
2022-01-24 16:29 ` Jan Beulich
2022-01-26 7:58 ` Wei Chen
2021-09-23 12:02 ` [PATCH 11/37] xen/x86: abstract neutral code from acpi_numa_memory_affinity_init Wei Chen
2021-09-24 0:38 ` Stefano Stabellini
2022-01-24 16:50 ` Jan Beulich
2022-01-26 10:39 ` Wei Chen
2021-09-23 12:02 ` [PATCH 12/37] xen/x86: decouple nodes_cover_memory from E820 map Wei Chen
2021-09-24 0:39 ` Stefano Stabellini
2022-01-24 16:59 ` Jan Beulich
2022-01-27 8:03 ` Wei Chen
2022-01-27 8:08 ` Jan Beulich
2022-01-27 9:03 ` Wei Chen
2022-01-27 9:22 ` Jan Beulich
2022-01-27 9:27 ` Wei Chen
2021-09-23 12:02 ` [PATCH 13/37] xen/x86: decouple processor_nodes_parsed from acpi numa functions Wei Chen
2021-09-24 0:40 ` Stefano Stabellini
2022-01-25 9:49 ` Jan Beulich
2022-01-27 8:06 ` Wei Chen
2021-09-23 12:02 ` [PATCH 14/37] xen/x86: use name fw_numa to replace acpi_numa Wei Chen
2021-09-24 0:40 ` Stefano Stabellini
2022-01-25 10:12 ` Jan Beulich
2022-01-27 8:09 ` Wei Chen
2021-09-23 12:02 ` [PATCH 15/37] xen/x86: rename acpi_scan_nodes to numa_scan_nodes Wei Chen
2021-09-24 0:40 ` Stefano Stabellini
2022-01-25 10:17 ` Jan Beulich
2022-01-27 8:14 ` Wei Chen
2021-09-23 12:02 ` [PATCH 16/37] xen/x86: export srat_bad to external Wei Chen
2021-09-24 0:41 ` Stefano Stabellini
2022-01-25 10:22 ` Jan Beulich
2022-01-27 8:35 ` Wei Chen
2022-01-27 8:37 ` Jan Beulich
2022-01-27 8:47 ` Wei Chen
2021-09-23 12:02 ` [PATCH 17/37] xen/x86: use CONFIG_NUMA to gate numa_scan_nodes Wei Chen
2021-09-24 0:41 ` Stefano Stabellini
2022-01-25 10:26 ` Jan Beulich
2022-01-27 8:37 ` Wei Chen
2021-09-23 12:02 ` [PATCH 18/37] xen: move NUMA common code from x86 to common Wei Chen
2021-09-23 12:02 ` [PATCH 19/37] xen/x86: promote VIRTUAL_BUG_ON to ASSERT in Wei Chen
2022-01-17 16:21 ` Jan Beulich
2022-01-18 7:52 ` Wei Chen
2021-09-23 12:02 ` [PATCH 20/37] xen: introduce CONFIG_EFI to stub API for non-EFI architecture Wei Chen
2021-09-24 1:15 ` Stefano Stabellini
2021-09-24 4:34 ` Wei Chen
2021-09-24 7:58 ` Jan Beulich
2021-09-24 10:31 ` Wei Chen
2021-09-24 10:49 ` Jan Beulich
2021-09-26 10:25 ` Wei Chen
2021-09-27 10:28 ` Wei Chen
2021-09-28 0:59 ` Stefano Stabellini
2021-09-28 4:16 ` Wei Chen
2021-09-28 5:01 ` Stefano Stabellini
2021-09-28 8:02 ` Jan Beulich
2021-10-03 23:28 ` Wei Chen
2022-01-25 10:34 ` Jan Beulich
2022-01-27 8:44 ` Wei Chen
2022-01-27 8:51 ` Wei Chen
2022-01-27 9:00 ` Jan Beulich
2022-01-27 9:09 ` Wei Chen
2022-01-27 9:16 ` Jan Beulich
2022-01-27 9:25 ` Wei Chen
2022-01-27 9:27 ` Jan Beulich
2022-01-27 10:00 ` Julien Grall
2022-01-28 4:35 ` Wei Chen
2021-09-23 12:02 ` [PATCH 21/37] xen/arm: Keep memory nodes in dtb for NUMA when boot from EFI Wei Chen
2021-09-24 1:23 ` Stefano Stabellini
2021-09-24 4:36 ` Wei Chen
2022-01-25 10:38 ` Jan Beulich
2022-01-27 8:45 ` Wei Chen
2021-09-23 12:02 ` [PATCH 22/37] xen/arm: use NR_MEM_BANKS to override default NR_NODE_MEMBLKS Wei Chen
2021-09-24 1:34 ` Stefano Stabellini
2021-09-26 13:13 ` Wei Chen
2021-09-27 3:25 ` Stefano Stabellini [this message]
2021-09-27 4:18 ` Wei Chen
2021-09-27 4:59 ` Stefano Stabellini
2021-09-27 6:25 ` Julien Grall
2021-09-27 6:46 ` Wei Chen
2021-09-27 6:53 ` Wei Chen
2021-09-27 7:35 ` Julien Grall
2021-09-27 10:21 ` Wei Chen
2021-09-27 10:39 ` Julien Grall
2021-09-27 16:58 ` Stefano Stabellini
2021-09-28 2:57 ` Wei Chen
2021-09-23 12:02 ` [PATCH 23/37] xen/arm: implement node distance helpers for Arm Wei Chen
2021-09-24 1:46 ` Stefano Stabellini
2021-09-24 4:41 ` Wei Chen
2021-09-24 19:36 ` Stefano Stabellini
2021-09-26 10:15 ` Wei Chen
2021-09-23 12:02 ` [PATCH 24/37] xen/arm: implement two arch helpers to get memory map info Wei Chen
2021-09-24 2:06 ` Stefano Stabellini
2021-09-24 4:42 ` Wei Chen
2021-09-23 12:02 ` [PATCH 25/37] xen/arm: implement bad_srat for Arm NUMA initialization Wei Chen
2021-09-24 2:09 ` Stefano Stabellini
2021-09-24 4:45 ` Wei Chen
2021-09-24 8:07 ` Jan Beulich
2021-09-24 19:33 ` Stefano Stabellini
2021-09-23 12:02 ` [PATCH 26/37] xen/arm: build NUMA cpu_to_node map in dt_smp_init_cpus Wei Chen
2021-09-24 2:26 ` Stefano Stabellini
2021-09-24 4:25 ` Wei Chen
2021-09-23 12:02 ` [PATCH 27/37] xen/arm: Add boot and secondary CPU to NUMA system Wei Chen
2021-09-23 12:02 ` [PATCH 28/37] xen/arm: stub memory hotplug access helpers for Arm Wei Chen
2021-09-24 2:33 ` Stefano Stabellini
2021-09-24 4:26 ` Wei Chen
2021-09-23 12:02 ` [PATCH 29/37] xen/arm: introduce a helper to parse device tree processor node Wei Chen
2021-09-24 2:44 ` Stefano Stabellini
2021-09-24 4:46 ` Wei Chen
2021-09-23 12:02 ` [PATCH 30/37] xen/arm: introduce a helper to parse device tree memory node Wei Chen
2021-09-24 3:05 ` Stefano Stabellini
2021-09-24 7:54 ` Wei Chen
2021-09-23 12:02 ` [PATCH 31/37] xen/arm: introduce a helper to parse device tree NUMA distance map Wei Chen
2021-09-24 3:05 ` Stefano Stabellini
2021-09-24 5:23 ` Wei Chen
2021-09-23 12:02 ` [PATCH 32/37] xen/arm: unified entry to parse all NUMA data from device tree Wei Chen
2021-09-24 3:16 ` Stefano Stabellini
2021-09-24 7:58 ` Wei Chen
2021-09-24 19:42 ` Stefano Stabellini
2021-09-23 12:02 ` [PATCH 33/37] xen/arm: keep guest still be NUMA unware Wei Chen
2021-09-24 3:19 ` Stefano Stabellini
2021-09-24 10:23 ` Wei Chen
2021-09-23 12:02 ` [PATCH 34/37] xen/arm: enable device tree based NUMA in system init Wei Chen
2021-09-24 3:28 ` Stefano Stabellini
2021-09-24 9:52 ` Wei Chen
2021-09-23 12:02 ` [PATCH 35/37] xen/arm: use CONFIG_NUMA to gate node_online_map in smpboot Wei Chen
2021-09-23 12:02 ` [PATCH 36/37] xen/arm: Provide Kconfig options for Arm to enable NUMA Wei Chen
2021-09-24 3:31 ` Stefano Stabellini
2021-09-24 10:13 ` Wei Chen
2021-09-24 19:39 ` Stefano Stabellini
2021-09-27 8:33 ` Jan Beulich
2021-09-27 8:45 ` Julien Grall
2021-09-27 9:17 ` Jan Beulich
2021-09-27 17:17 ` Stefano Stabellini
2021-09-28 2:59 ` Wei Chen
2021-09-28 3:30 ` Stefano Stabellini
2021-09-24 10:25 ` Jan Beulich
2021-09-24 10:37 ` Wei Chen
2021-09-23 12:02 ` [PATCH 37/37] docs: update numa command line to support Arm Wei Chen
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