From: Nathan Lynch <nathanl@linux.ibm.com>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
Scott Cheloha <cheloha@linux.ibm.com>,
Geetika Moolchandani <Geetika.Moolchandani1@ibm.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Laurent Dufour <ldufour@linux.vnet.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH 1/1] powerpc/smp: Set numa node before updating mask
Date: Wed, 07 Apr 2021 14:46:24 -0500 [thread overview]
Message-ID: <878s5tlvxr.fsf@linux.ibm.com> (raw)
In-Reply-To: <20210407164930.GJ2339179@linux.vnet.ibm.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> * Nathan Lynch <nathanl@linux.ibm.com> [2021-04-07 07:19:10]:
>
>> Sorry for the delay in following up here.
>>
>
> No issues.
>
>> >> So I'd suggest that pseries_add_processor() be made to update
>> >> these things when the CPUs are marked present, before onlining them.
>> >
>> > In pseries_add_processor, we are only marking the cpu as present. i.e
>> > I believe numa_setup_cpu() would not have been called. So we may not have a
>> > way to associate the CPU to the node. Otherwise we will have to call
>> > numa_setup_cpu() or the hcall_vphn.
>> >
>> > We could try calling numa_setup_cpu() immediately after we set the
>> > CPU to be present, but that would be one more extra hcall + I dont know if
>> > there are any more steps needed before CPU being made present and
>> > associating the CPU to the node.
>>
>> An additional hcall in this path doesn't seem too expensive.
>>
>> > Are we sure the node is already online?
>>
>> I see that dlpar_online_cpu() calls find_and_online_cpu_nid(), so yes I
>> think that's covered.
>
> Okay,
>
> Can we just call set_cpu_numa_node() at the end of map_cpu_to_node().
> The advantage would be the update to numa_cpu_lookup_table and cpu_to_node
> would happen at the same time and would be in sync.
I don't know. I guess this question just makes me wonder whether powerpc
needs to have the additional lookup table. How is it different from the
generic per_cpu numa_node?
next prev parent reply other threads:[~2021-04-07 19:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 15:42 [PATCH 1/1] powerpc/smp: Set numa node before updating mask Srikar Dronamraju
2021-04-01 22:51 ` Nathan Lynch
2021-04-02 3:18 ` Srikar Dronamraju
2021-04-07 12:19 ` Nathan Lynch
2021-04-07 16:49 ` Srikar Dronamraju
2021-04-07 19:46 ` Nathan Lynch [this message]
2021-04-08 11:11 ` Srikar Dronamraju
2021-04-08 20:00 ` Nathan Lynch
2021-04-09 10:14 ` Srikar Dronamraju
2021-04-13 12:23 ` Nathan Lynch
2021-04-13 12:25 ` Nathan Lynch
2021-04-19 4:00 ` Michael Ellerman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=878s5tlvxr.fsf@linux.ibm.com \
--to=nathanl@linux.ibm.com \
--cc=Geetika.Moolchandani1@ibm.com \
--cc=cheloha@linux.ibm.com \
--cc=ego@linux.vnet.ibm.com \
--cc=ldufour@linux.vnet.ibm.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=valentin.schneider@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).