From: "wangyanan (Y)" <wangyanan55@huawei.com>
To: Andrew Jones <drjones@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
"Michael S . Tsirkin" <mst@redhat.com>,
qemu-devel@nongnu.org, Shannon Zhao <shannon.zhaosl@gmail.com>,
Igor Mammedov <imammedo@redhat.com>,
qemu-arm@nongnu.org, Alistair Francis <alistair.francis@wdc.com>,
prime.zeng@hisilicon.com, yangyicong@huawei.com,
yuzenghui@huawei.com, wanghaibin.wang@huawei.com,
zhukeqian1@huawei.com, Jiajie Li <lijiajie11@huawei.com>,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [RFC PATCH v2 6/6] hw/arm/virt: Replace smp_parse with one that prefers cores
Date: Wed, 28 Apr 2021 16:04:18 +0800 [thread overview]
Message-ID: <db9cb1b8-1399-aa29-f8a5-874f6508f330@huawei.com> (raw)
In-Reply-To: <20210427145856.5qaetgzdl6ovnoni@gator.home>
Hi Drew,
On 2021/4/27 22:58, Andrew Jones wrote:
> On Tue, Apr 13, 2021 at 04:07:45PM +0800, Yanan Wang wrote:
>> From: Andrew Jones <drjones@redhat.com>
>>
>> The virt machine type has never used the CPU topology parameters, other
>> than number of online CPUs and max CPUs. When choosing how to allocate
>> those CPUs the default has been to assume cores. In preparation for
>> using the other CPU topology parameters let's use an smp_parse that
>> prefers cores over sockets. We can also enforce the topology matches
>> max_cpus check because we have no legacy to preserve.
>>
>> Signed-off-by: Andrew Jones <drjones@redhat.com>
>> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
>> ---
>> hw/arm/virt.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 76 insertions(+)
> Thanks, this patch matches [1]. Of course, I've always considered this
> patch to be something of an RFC, though. Is there any harm in defaulting
> to sockets over cores? If not, I wonder if we shouldn't just leave the
> default as it is to avoid a mach-virt specific smp parser.
From my view, I did't find any harm in defaulting to sockets over
cores, but I'm not really sure..
At least, the arch-neutral function smp_parse and pc_smp_parse for x86
all prefer sockets over cores in default.
> The "no
> topology" compat variable will keep existing machine types from switching
> from cores to sockets, so we don't need to worry about that.
Yes, I agree about this.
Thanks,
Yanan
> [1] https://github.com/rhdrjones/qemu/commit/c0670b1bccb4d08c7cf7c6957cc8878a2af131dd
>
> Thanks,
> drew
>
>
> .
next prev parent reply other threads:[~2021-04-28 8:07 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 8:07 [RFC PATCH v2 0/6] hw/arm/virt: Introduce cpu topology support Yanan Wang
2021-04-13 8:07 ` [RFC PATCH v2 1/6] device_tree: Add qemu_fdt_add_path Yanan Wang
2021-04-16 4:52 ` David Gibson
2021-04-17 2:36 ` wangyanan (Y)
2021-04-19 1:13 ` David Gibson
2021-04-19 7:02 ` wangyanan (Y)
2021-04-13 8:07 ` [RFC PATCH v2 2/6] hw/arm/virt: DT: Add cpu-map Yanan Wang
2021-04-27 9:47 ` Philippe Mathieu-Daudé
2021-04-27 10:04 ` Andrew Jones
2021-04-27 12:36 ` Philippe Mathieu-Daudé
2021-04-28 6:36 ` wangyanan (Y)
2021-05-13 6:58 ` Andrew Jones
2021-05-13 7:15 ` wangyanan (Y)
2021-04-13 8:07 ` [RFC PATCH v2 3/6] hw/arm/virt-acpi-build: Distinguish possible and present cpus Yanan Wang
2021-04-27 13:18 ` Andrew Jones
2021-04-28 6:42 ` wangyanan (Y)
2021-04-27 14:50 ` Andrew Jones
2021-04-28 6:47 ` wangyanan (Y)
2021-04-13 8:07 ` [RFC PATCH v2 4/6] hw/acpi/aml-build: Add processor hierarchy node structure Yanan Wang
2021-04-27 13:37 ` Andrew Jones
2021-04-28 6:59 ` wangyanan (Y)
2021-04-13 8:07 ` [RFC PATCH v2 5/6] hw/arm/virt-acpi-build: Add PPTT table Yanan Wang
2021-04-27 14:16 ` Andrew Jones
2021-04-28 7:30 ` wangyanan (Y)
2021-05-13 5:10 ` wangyanan (Y)
2021-05-13 6:55 ` Andrew Jones
2021-05-18 7:17 ` Salil Mehta
2021-05-18 7:42 ` Andrew Jones
2021-05-18 18:34 ` Salil Mehta
2021-05-18 19:05 ` Andrew Jones
2021-05-18 19:22 ` Salil Mehta
2021-05-19 3:18 ` wangyanan (Y)
2021-05-19 7:54 ` Salil Mehta
2021-05-19 8:15 ` Andrew Jones
2021-05-19 8:42 ` wangyanan (Y)
2021-05-19 10:00 ` Salil Mehta
2021-05-19 8:27 ` Andrew Jones
2021-05-19 13:26 ` wangyanan (Y)
2021-05-19 13:40 ` wangyanan (Y)
2021-05-18 9:16 ` wangyanan (Y)
2021-04-13 8:07 ` [RFC PATCH v2 6/6] hw/arm/virt: Replace smp_parse with one that prefers cores Yanan Wang
2021-04-27 14:58 ` Andrew Jones
2021-04-28 8:04 ` wangyanan (Y) [this message]
2021-04-28 9:36 ` wangyanan (Y)
2021-04-28 10:13 ` Andrew Jones
2021-04-29 2:21 ` wangyanan (Y)
2021-04-21 7:40 ` [RFC PATCH v2 0/6] hw/arm/virt: Introduce cpu topology support wangyanan (Y)
2021-04-21 9:31 ` wangyanan (Y)
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=db9cb1b8-1399-aa29-f8a5-874f6508f330@huawei.com \
--to=wangyanan55@huawei.com \
--cc=alistair.francis@wdc.com \
--cc=david@gibson.dropbear.id.au \
--cc=drjones@redhat.com \
--cc=imammedo@redhat.com \
--cc=lijiajie11@huawei.com \
--cc=mst@redhat.com \
--cc=peter.maydell@linaro.org \
--cc=prime.zeng@hisilicon.com \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=shannon.zhaosl@gmail.com \
--cc=wanghaibin.wang@huawei.com \
--cc=yangyicong@huawei.com \
--cc=yuzenghui@huawei.com \
--cc=zhukeqian1@huawei.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).