From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
To: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org
Cc: guz.fnst@cn.fujitsu.com
Subject: logical cpu number is discontinuity
Date: Wed, 18 Jan 2017 14:55:56 +0900 [thread overview]
Message-ID: <587F036C.7050200@jp.fujitsu.com> (raw)
Hi,
On v4.9 and v4.10 kernel, when I booted my box which has two nodes and
each nodes have 48 logical cpus (Hyper Threading is enabled),
the logical cpu number is discontinuity as follows.
node 0: 0-23, 256-279
node 1: 24-47, 280-303
So the following shell script fail to run.
---
#!/bin/bash
for ((cpu = 0; cpu < `nproc`; cpu++))
do
taskset -c $cpu ./do_work
done
---
I think the logical cpu number should be continuity like as v4.8 and earlier
because user applications may expect the number is continuity.
I believe this behavior was introduced by the patch series beginning with
the following commit.
f7c2883 x86/acpi: Enable acpi to register all possible cpus at boot time
Do anyone have ideas for fix this behavior...?
FYI.
v4.8 kernel, the logical cpu number is continuity as follows.
node 0: 0-23, 48-71
node 1: 24-47, 72-95
- Masayoshi Mizuma
WARNING: multiple messages have this Message-ID (diff)
From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
To: <linux-kernel@vger.kernel.org>, <linux-acpi@vger.kernel.org>
Cc: <guz.fnst@cn.fujitsu.com>
Subject: logical cpu number is discontinuity
Date: Wed, 18 Jan 2017 14:55:56 +0900 [thread overview]
Message-ID: <587F036C.7050200@jp.fujitsu.com> (raw)
Hi,
On v4.9 and v4.10 kernel, when I booted my box which has two nodes and
each nodes have 48 logical cpus (Hyper Threading is enabled),
the logical cpu number is discontinuity as follows.
node 0: 0-23, 256-279
node 1: 24-47, 280-303
So the following shell script fail to run.
---
#!/bin/bash
for ((cpu = 0; cpu < `nproc`; cpu++))
do
taskset -c $cpu ./do_work
done
---
I think the logical cpu number should be continuity like as v4.8 and earlier
because user applications may expect the number is continuity.
I believe this behavior was introduced by the patch series beginning with
the following commit.
f7c2883 x86/acpi: Enable acpi to register all possible cpus at boot time
Do anyone have ideas for fix this behavior...?
FYI.
v4.8 kernel, the logical cpu number is continuity as follows.
node 0: 0-23, 48-71
node 1: 24-47, 72-95
- Masayoshi Mizuma
next reply other threads:[~2017-01-18 6:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-18 5:55 Masayoshi Mizuma [this message]
2017-01-18 5:55 ` logical cpu number is discontinuity Masayoshi Mizuma
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