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From: Laurent Dufour <ldufour@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	mpe@ellerman.id.au, npiggin@gmail.com,
	christophe.leroy@csgroup.eu, tglx@linutronix.de,
	dave.hansen@linux.intel.com, mingo@redhat.com, bp@alien8.de,
	rui.zhang@intel.com
Subject: [PATCH v4 05/10] cpu/SMT: Remove topology_smt_supported()
Date: Wed,  5 Jul 2023 16:51:38 +0200	[thread overview]
Message-ID: <20230705145143.40545-6-ldufour@linux.ibm.com> (raw)
In-Reply-To: <20230705145143.40545-1-ldufour@linux.ibm.com>

Since the maximum number of threads is now passed to
cpu_smt_set_num_threads(), checking that value is enough to know if SMT is
supported.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
---
 arch/x86/include/asm/topology.h | 2 --
 arch/x86/kernel/smpboot.c       | 8 --------
 kernel/cpu.c                    | 4 ++--
 3 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index ae49ed4417d0..3235ba1e5b06 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -141,7 +141,6 @@ static inline int topology_max_smt_threads(void)
 int topology_update_package_map(unsigned int apicid, unsigned int cpu);
 int topology_update_die_map(unsigned int dieid, unsigned int cpu);
 int topology_phys_to_logical_pkg(unsigned int pkg);
-bool topology_smt_supported(void);
 
 extern struct cpumask __cpu_primary_thread_mask;
 #define cpu_primary_thread_mask ((const struct cpumask *)&__cpu_primary_thread_mask)
@@ -164,7 +163,6 @@ static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return 0; }
 static inline int topology_max_die_per_package(void) { return 1; }
 static inline int topology_max_smt_threads(void) { return 1; }
 static inline bool topology_is_primary_thread(unsigned int cpu) { return true; }
-static inline bool topology_smt_supported(void) { return false; }
 #endif /* !CONFIG_SMP */
 
 static inline void arch_fix_phys_package_id(int num, u32 slot)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index ed2d51960a7d..f8e709fd2cd5 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -326,14 +326,6 @@ static void notrace start_secondary(void *unused)
 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 }
 
-/**
- * topology_smt_supported - Check whether SMT is supported by the CPUs
- */
-bool topology_smt_supported(void)
-{
-	return smp_num_siblings > 1;
-}
-
 /**
  * topology_phys_to_logical_pkg - Map a physical package id to a logical
  * @phys_pkg:	The physical package id to map
diff --git a/kernel/cpu.c b/kernel/cpu.c
index d7dd535cb5b5..70add058e77b 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -621,7 +621,7 @@ void __init cpu_smt_set_num_threads(unsigned int num_threads,
 {
 	WARN_ON(!num_threads || (num_threads > max_threads));
 
-	if (!topology_smt_supported())
+	if (max_threads == 1)
 		cpu_smt_control = CPU_SMT_NOT_SUPPORTED;
 
 	cpu_smt_max_threads = max_threads;
@@ -1801,7 +1801,7 @@ early_param("cpuhp.parallel", parallel_bringup_parse_param);
 
 static inline bool cpuhp_smt_aware(void)
 {
-	return topology_smt_supported();
+	return cpu_smt_max_threads > 1;
 }
 
 static inline const struct cpumask *cpuhp_get_primary_thread_mask(void)
-- 
2.41.0


  parent reply	other threads:[~2023-07-05 14:52 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-05 14:51 [PATCH v4 00/10] Introduce SMT level and add PowerPC support Laurent Dufour
2023-07-05 14:51 ` [PATCH v4 01/10] cpu/hotplug: remove dependancy against cpu_primary_thread_mask Laurent Dufour
2023-07-05 14:51 ` [PATCH v4 02/10] cpu/SMT: Move SMT prototypes into cpu_smt.h Laurent Dufour
2023-07-05 14:51 ` [PATCH v4 03/10] cpu/SMT: Move smt/control simple exit cases earlier Laurent Dufour
2023-07-05 14:51 ` [PATCH v4 04/10] cpu/SMT: Store the current/max number of threads Laurent Dufour
2023-07-05 14:51 ` Laurent Dufour [this message]
2023-07-05 14:51 ` [PATCH v4 06/10] cpu/SMT: Create topology_smt_thread_allowed() Laurent Dufour
2023-07-05 14:51 ` [PATCH v4 07/10] cpu/SMT: Allow enabling partial SMT states via sysfs Laurent Dufour
2024-04-08 14:13   ` Michal Suchánek
2023-07-05 14:51 ` [PATCH v4 08/10] powerpc/pseries: Initialise CPU hotplug callbacks earlier Laurent Dufour
2023-08-14 10:51   ` Srikar Dronamraju
2023-07-05 14:51 ` [PATCH v4 09/10] powerpc: Add HOTPLUG_SMT support Laurent Dufour
2023-08-14 10:52   ` Srikar Dronamraju
2023-07-05 14:51 ` [PATCH v4 10/10] powerpc/pseries: Honour current SMT state when DLPAR onlining CPUs Laurent Dufour
2023-08-14 10:53   ` Srikar Dronamraju
2023-07-09 15:25 ` [PATCH v4 00/10] Introduce SMT level and add PowerPC support Zhang, Rui
2023-07-10  9:08   ` Laurent Dufour
2023-07-28  7:40   ` Thomas Gleixner
2023-07-28 14:23     ` Zhang, Rui
2023-07-28 14:51       ` Thomas Gleixner
2023-07-28  7:58 ` Thomas Gleixner
2023-07-31 11:55   ` Laurent Dufour
2023-08-10  6:23   ` Michael Ellerman
2023-08-10  8:51     ` Laurent Dufour

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