From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: Mark Rutland <mark.rutland@arm.com>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>,
Rohan McLure <rmclure@linux.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Josh Poimboeuf <jpoimboe@kernel.org>
Subject: Re: [PATCH v4 0/5] powerpc/smp: Topology and shared processor optimizations
Date: Wed, 15 Nov 2023 11:24:59 +0530 [thread overview]
Message-ID: <87v8a3zhl8.fsf@linux.ibm.com> (raw)
In-Reply-To: <20231109054938.26589-1-srikar@linux.vnet.ibm.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> PowerVM systems configured in shared processors mode have some unique
> challenges. Some device-tree properties will be missing on a shared
> processor. Hence some sched domains may not make sense for shared processor
> systems.
>
> Most shared processor systems are over-provisioned. Underlying PowerVM
> Hypervisor would schedule at a Big Core granularity. The most recent power
> processors support two almost independent cores. In a lightly loaded
> condition, it helps the overall system performance if we pack to lesser
> number of Big Cores.
>
Is this good to do if the systems are not over-provisioned? What will be
the performance impact in that case with and without the change?
-aneesh
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: Mark Rutland <mark.rutland@arm.com>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org,
Rohan McLure <rmclure@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Josh Poimboeuf <jpoimboe@kernel.org>
Subject: Re: [PATCH v4 0/5] powerpc/smp: Topology and shared processor optimizations
Date: Wed, 15 Nov 2023 11:24:59 +0530 [thread overview]
Message-ID: <87v8a3zhl8.fsf@linux.ibm.com> (raw)
In-Reply-To: <20231109054938.26589-1-srikar@linux.vnet.ibm.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> PowerVM systems configured in shared processors mode have some unique
> challenges. Some device-tree properties will be missing on a shared
> processor. Hence some sched domains may not make sense for shared processor
> systems.
>
> Most shared processor systems are over-provisioned. Underlying PowerVM
> Hypervisor would schedule at a Big Core granularity. The most recent power
> processors support two almost independent cores. In a lightly loaded
> condition, it helps the overall system performance if we pack to lesser
> number of Big Cores.
>
Is this good to do if the systems are not over-provisioned? What will be
the performance impact in that case with and without the change?
-aneesh
next prev parent reply other threads:[~2023-11-15 5:56 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-09 5:49 [PATCH v4 0/5] powerpc/smp: Topology and shared processor optimizations Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-09 5:49 ` [PATCH v4 1/5] powerpc/smp: Enable Asym packing for cores on shared processor Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-15 5:27 ` Aneesh Kumar K.V
2023-11-15 5:42 ` Srikar Dronamraju
2023-11-15 5:42 ` Srikar Dronamraju
2023-11-15 6:35 ` Aneesh Kumar K.V
2023-11-15 11:35 ` Srikar Dronamraju
2023-11-15 11:35 ` Srikar Dronamraju
2023-11-09 5:49 ` [PATCH v4 2/5] powerpc/smp: Disable MC domain for " Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-09 5:49 ` [PATCH v4 3/5] powerpc/smp: Add __ro_after_init attribute Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-09 5:49 ` [PATCH v4 4/5] powerpc/smp: Avoid asym packing within thread_group of a core Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-09 5:49 ` [PATCH v4 5/5] powerpc/smp: Dynamically build Powerpc topology Srikar Dronamraju
2023-11-09 5:49 ` Srikar Dronamraju
2023-11-15 5:54 ` Aneesh Kumar K.V [this message]
2023-11-15 5:54 ` [PATCH v4 0/5] powerpc/smp: Topology and shared processor optimizations Aneesh Kumar K.V
2023-11-15 6:16 ` Srikar Dronamraju
2023-11-15 6:16 ` Srikar Dronamraju
2023-12-11 2:56 ` Srikar Dronamraju
2023-12-11 2:56 ` Srikar Dronamraju
2023-12-11 10:45 ` Michael Ellerman
2023-12-11 10:45 ` Michael Ellerman
2023-12-13 11:20 ` Aneesh Kumar K.V
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