From: Michael Ellerman <mpe@ellerman.id.au>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Valentin Schneider <vschneid@redhat.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
"ndesaulniers@google.com" <ndesaulniers@google.com>,
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 v2 5/6] powerpc/smp: Add read_mostly attribute
Date: Thu, 19 Oct 2023 15:49:48 +1100 [thread overview]
Message-ID: <87mswf5i8j.fsf@mail.lhotse> (raw)
In-Reply-To: <20231018163751.2423181-6-srikar@linux.vnet.ibm.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> There are some variables that are only updated at boot time.
> So add read_mostly attribute to such variables
If they're only updated at boot time then __ro_after_init would be the
better annotation.
cheers
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index 29da9262cb17..b1eb11a66902 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -77,10 +77,10 @@ static DEFINE_PER_CPU(int, cpu_state) = { 0 };
> #endif
>
> struct task_struct *secondary_current;
> -bool has_big_cores;
> -bool coregroup_enabled;
> -bool thread_group_shares_l2;
> -bool thread_group_shares_l3;
> +bool has_big_cores __read_mostly;
> +bool coregroup_enabled __read_mostly;
> +bool thread_group_shares_l2 __read_mostly;
> +bool thread_group_shares_l3 __read_mostly;
>
> DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
> DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
> @@ -987,7 +987,7 @@ static int __init init_thread_group_cache_map(int cpu, int cache_property)
> return 0;
> }
>
> -static bool shared_caches;
> +static bool shared_caches __read_mostly;
> DEFINE_STATIC_KEY_FALSE(powerpc_asym_packing);
>
> #ifdef CONFIG_SCHED_SMT
> --
> 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <mpe@ellerman.id.au>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Nicholas Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Rohan McLure <rmclure@linux.ibm.com>,
Valentin Schneider <vschneid@redhat.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
"ndesaulniers@google.com" <ndesaulniers@google.com>,
Mark Rutland <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/6] powerpc/smp: Add read_mostly attribute
Date: Thu, 19 Oct 2023 15:49:48 +1100 [thread overview]
Message-ID: <87mswf5i8j.fsf@mail.lhotse> (raw)
In-Reply-To: <20231018163751.2423181-6-srikar@linux.vnet.ibm.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com> writes:
> There are some variables that are only updated at boot time.
> So add read_mostly attribute to such variables
If they're only updated at boot time then __ro_after_init would be the
better annotation.
cheers
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index 29da9262cb17..b1eb11a66902 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -77,10 +77,10 @@ static DEFINE_PER_CPU(int, cpu_state) = { 0 };
> #endif
>
> struct task_struct *secondary_current;
> -bool has_big_cores;
> -bool coregroup_enabled;
> -bool thread_group_shares_l2;
> -bool thread_group_shares_l3;
> +bool has_big_cores __read_mostly;
> +bool coregroup_enabled __read_mostly;
> +bool thread_group_shares_l2 __read_mostly;
> +bool thread_group_shares_l3 __read_mostly;
>
> DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
> DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
> @@ -987,7 +987,7 @@ static int __init init_thread_group_cache_map(int cpu, int cache_property)
> return 0;
> }
>
> -static bool shared_caches;
> +static bool shared_caches __read_mostly;
> DEFINE_STATIC_KEY_FALSE(powerpc_asym_packing);
>
> #ifdef CONFIG_SCHED_SMT
> --
> 2.31.1
next prev parent reply other threads:[~2023-10-19 4:50 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-18 16:37 [PATCH v2 0/6] powerpc/smp: Shared processor sched optimizations Srikar Dronamraju
2023-10-18 16:37 ` [PATCH v2 1/6] powerpc/smp: Cache CPU has Asymmetric SMP Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
2023-10-19 4:33 ` Michael Ellerman
2023-10-19 4:33 ` Michael Ellerman
2023-10-20 9:09 ` Srikar Dronamraju
2023-10-20 9:09 ` Srikar Dronamraju
2023-10-18 16:37 ` [PATCH v2 2/6] powerpc/smp: Enable Asym packing for cores on shared processor Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
2023-10-19 4:38 ` Michael Ellerman
2023-10-19 4:38 ` Michael Ellerman
2023-10-19 7:48 ` Peter Zijlstra
2023-10-19 7:48 ` Peter Zijlstra
2023-10-19 11:50 ` Michael Ellerman
2023-10-19 11:50 ` Michael Ellerman
2023-10-19 12:54 ` Srikar Dronamraju
2023-10-19 12:54 ` Srikar Dronamraju
2023-10-19 15:56 ` Shrikanth Hegde
2023-10-19 15:56 ` Shrikanth Hegde
2023-10-20 5:44 ` Srikar Dronamraju
2023-10-20 5:44 ` Srikar Dronamraju
2023-10-18 16:37 ` [PATCH v2 3/6] powerpc/smp: Move shared_processor static key to smp.h Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
2023-10-19 4:41 ` Michael Ellerman
2023-10-19 4:41 ` Michael Ellerman
2023-10-19 4:41 ` Michael Ellerman
2023-10-19 13:08 ` Srikar Dronamraju
2023-10-19 13:08 ` Srikar Dronamraju
2023-10-20 10:44 ` Michael Ellerman
2023-10-20 10:44 ` Michael Ellerman
2023-10-20 10:44 ` Michael Ellerman
2023-10-19 10:30 ` Shrikanth Hegde
2023-10-19 10:30 ` Shrikanth Hegde
2023-10-18 16:37 ` [PATCH v2 4/6] powerpc/smp: Disable MC domain for shared processor Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
2023-10-19 4:48 ` Michael Ellerman
2023-10-19 4:48 ` Michael Ellerman
2023-10-19 7:50 ` Peter Zijlstra
2023-10-19 7:50 ` Peter Zijlstra
2023-10-19 13:23 ` Srikar Dronamraju
2023-10-19 13:23 ` Srikar Dronamraju
2023-10-19 13:16 ` Srikar Dronamraju
2023-10-19 13:16 ` Srikar Dronamraju
2023-10-18 16:37 ` [PATCH v2 5/6] powerpc/smp: Add read_mostly attribute Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
2023-10-19 4:49 ` Michael Ellerman [this message]
2023-10-19 4:49 ` Michael Ellerman
2023-10-19 7:51 ` Peter Zijlstra
2023-10-19 7:51 ` Peter Zijlstra
2023-10-19 12:56 ` Srikar Dronamraju
2023-10-19 12:56 ` Srikar Dronamraju
2023-10-18 16:37 ` [PATCH v2 6/6] powerpc/smp: Avoid asym packing within thread_group of a core Srikar Dronamraju
2023-10-18 16:37 ` Srikar Dronamraju
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