From: Sudeep Holla <sudeep.holla@arm.com>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>,
linux-kernel@vger.kernel.org, Atish Patra <atishp@rivosinc.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qing Wang <wangqing@vivo.com>,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v2 2/8] arch_topology: Set thread sibling cpumask only within the cluster
Date: Fri, 20 May 2022 14:20:25 +0100 [thread overview]
Message-ID: <20220520132025.sbbmnusnmls3ruow@bogus> (raw)
In-Reply-To: <db6dc5e0-780a-5542-5e49-711cd454a9d8@arm.com>
On Fri, May 20, 2022 at 02:32:19PM +0200, Dietmar Eggemann wrote:
> On 18/05/2022 11:33, Sudeep Holla wrote:
> > Currently the cluster identifier is not set on the DT based platforms.
> > The reset or default value is -1 for all the CPUs. Once we assign the
> > cluster identifier values correctly that imay result in getting the thread
> > siblings wrongs as the core identifiers can be same for 2 different CPUs
> > belonging to 2 different cluster.
> >
> > So, in order to get the thread sibling cpumasks correct, we need to
> > update them only if the cores they belong are in the same cluster within
> > the socket. Let us skip updation of the thread sibling cpumaks if the
> > cluster identifier doesn't match.
>
> So this issue should be there on ACPI systems as well then. Kunpeng920
> and Ampere Altra don't have SMT, so very likely nobody has noticed this
> so far.
No, I think it is handled correctly. May be the wordings of my commit log
needs changing. Previously the core ids were generated and unique across the
platform. But with this change I am assigned the id as read from the DT
node using core@<id>. That results in the problem and needs to be taken care.
This doesn't change the end result(the actual mask) but the way we arrive at
that. In short this is not fixing any issue that was broken before.
--
Regards,
Sudeep
WARNING: multiple messages have this Message-ID (diff)
From: Sudeep Holla <sudeep.holla@arm.com>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>,
linux-kernel@vger.kernel.org, Atish Patra <atishp@rivosinc.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qing Wang <wangqing@vivo.com>,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v2 2/8] arch_topology: Set thread sibling cpumask only within the cluster
Date: Fri, 20 May 2022 14:20:25 +0100 [thread overview]
Message-ID: <20220520132025.sbbmnusnmls3ruow@bogus> (raw)
In-Reply-To: <db6dc5e0-780a-5542-5e49-711cd454a9d8@arm.com>
On Fri, May 20, 2022 at 02:32:19PM +0200, Dietmar Eggemann wrote:
> On 18/05/2022 11:33, Sudeep Holla wrote:
> > Currently the cluster identifier is not set on the DT based platforms.
> > The reset or default value is -1 for all the CPUs. Once we assign the
> > cluster identifier values correctly that imay result in getting the thread
> > siblings wrongs as the core identifiers can be same for 2 different CPUs
> > belonging to 2 different cluster.
> >
> > So, in order to get the thread sibling cpumasks correct, we need to
> > update them only if the cores they belong are in the same cluster within
> > the socket. Let us skip updation of the thread sibling cpumaks if the
> > cluster identifier doesn't match.
>
> So this issue should be there on ACPI systems as well then. Kunpeng920
> and Ampere Altra don't have SMT, so very likely nobody has noticed this
> so far.
No, I think it is handled correctly. May be the wordings of my commit log
needs changing. Previously the core ids were generated and unique across the
platform. But with this change I am assigned the id as read from the DT
node using core@<id>. That results in the problem and needs to be taken care.
This doesn't change the end result(the actual mask) but the way we arrive at
that. In short this is not fixing any issue that was broken before.
--
Regards,
Sudeep
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
WARNING: multiple messages have this Message-ID (diff)
From: Sudeep Holla <sudeep.holla@arm.com>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Atish Patra <atishp@atishpatra.org>,
linux-kernel@vger.kernel.org, Atish Patra <atishp@rivosinc.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qing Wang <wangqing@vivo.com>,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v2 2/8] arch_topology: Set thread sibling cpumask only within the cluster
Date: Fri, 20 May 2022 14:20:25 +0100 [thread overview]
Message-ID: <20220520132025.sbbmnusnmls3ruow@bogus> (raw)
In-Reply-To: <db6dc5e0-780a-5542-5e49-711cd454a9d8@arm.com>
On Fri, May 20, 2022 at 02:32:19PM +0200, Dietmar Eggemann wrote:
> On 18/05/2022 11:33, Sudeep Holla wrote:
> > Currently the cluster identifier is not set on the DT based platforms.
> > The reset or default value is -1 for all the CPUs. Once we assign the
> > cluster identifier values correctly that imay result in getting the thread
> > siblings wrongs as the core identifiers can be same for 2 different CPUs
> > belonging to 2 different cluster.
> >
> > So, in order to get the thread sibling cpumasks correct, we need to
> > update them only if the cores they belong are in the same cluster within
> > the socket. Let us skip updation of the thread sibling cpumaks if the
> > cluster identifier doesn't match.
>
> So this issue should be there on ACPI systems as well then. Kunpeng920
> and Ampere Altra don't have SMT, so very likely nobody has noticed this
> so far.
No, I think it is handled correctly. May be the wordings of my commit log
needs changing. Previously the core ids were generated and unique across the
platform. But with this change I am assigned the id as read from the DT
node using core@<id>. That results in the problem and needs to be taken care.
This doesn't change the end result(the actual mask) but the way we arrive at
that. In short this is not fixing any issue that was broken before.
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-05-20 13:21 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 9:33 [PATCH v2 0/8] arch_topology: Updates to add socket support and fix cluster ids Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 1/8] arch_topology: Don't set cluster identifier as physical package identifier Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-20 12:31 ` Dietmar Eggemann
2022-05-20 12:31 ` Dietmar Eggemann
2022-05-20 12:31 ` Dietmar Eggemann
2022-05-20 13:13 ` Sudeep Holla
2022-05-20 13:13 ` Sudeep Holla
2022-05-20 13:13 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 2/8] arch_topology: Set thread sibling cpumask only within the cluster Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-20 12:32 ` Dietmar Eggemann
2022-05-20 12:32 ` Dietmar Eggemann
2022-05-20 12:32 ` Dietmar Eggemann
2022-05-20 13:20 ` Sudeep Holla [this message]
2022-05-20 13:20 ` Sudeep Holla
2022-05-20 13:20 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 3/8] arch_topology: Set cluster identifier in each core/thread from /cpu-map Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-19 16:55 ` Ionela Voinescu
2022-05-19 16:55 ` Ionela Voinescu
2022-05-19 16:55 ` Ionela Voinescu
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 13:54 ` Sudeep Holla
2022-05-20 13:54 ` Sudeep Holla
2022-05-20 13:54 ` Sudeep Holla
2022-05-20 15:27 ` Sudeep Holla
2022-05-20 15:27 ` Sudeep Holla
2022-05-20 15:27 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 4/8] arch_topology: Add support for parsing sockets in /cpu-map Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 5/8] arch_topology: Check for non-negative value rather than -1 for IDs validity Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 6/8] arch_topology: Avoid parsing through all the CPUs once a outlier CPU is found Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 7/8] of: base: add support to get the device node for the CPU's last level cache Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` [PATCH v2 8/8] arch_topology: Add support to build llc_sibling on DT platforms Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-18 9:33 ` Sudeep Holla
2022-05-19 18:10 ` Rob Herring
2022-05-19 18:10 ` Rob Herring
2022-05-19 18:10 ` Rob Herring
2022-05-20 12:59 ` Sudeep Holla
2022-05-20 12:59 ` Sudeep Holla
2022-05-20 12:59 ` Sudeep Holla
2022-05-20 14:36 ` Rob Herring
2022-05-20 14:36 ` Rob Herring
2022-05-20 14:36 ` Rob Herring
2022-05-20 15:06 ` Sudeep Holla
2022-05-20 15:06 ` Sudeep Holla
2022-05-20 15:06 ` Sudeep Holla
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 12:33 ` Dietmar Eggemann
2022-05-20 14:56 ` Sudeep Holla
2022-05-20 14:56 ` Sudeep Holla
2022-05-20 14:56 ` Sudeep Holla
2022-05-19 16:32 ` [PATCH v2 0/8] arch_topology: Updates to add socket support and fix cluster ids Ionela Voinescu
2022-05-19 16:32 ` Ionela Voinescu
2022-05-19 16:32 ` Ionela Voinescu
2022-05-20 15:33 ` Sudeep Holla
2022-05-20 15:33 ` Sudeep Holla
2022-05-20 15:33 ` Sudeep Holla
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