From: Usama Arif <usama.arif@bytedance.com>
To: dwmw2@infradead.org, tglx@linutronix.de
Cc: mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com,
paulmck@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, rcu@vger.kernel.org, mimoja@mimoja.de,
hewenliang4@huawei.com, thomas.lendacky@amd.com,
seanjc@google.com, pmenzel@molgen.mpg.de,
fam.zheng@bytedance.com, punit.agrawal@bytedance.com,
simon.evans@bytedance.com, liangma@liangbit.com,
David Woodhouse <dwmw@amazon.co.uk>
Subject: [PATCH 2/9] cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h>
Date: Wed, 1 Feb 2023 20:43:31 +0000 [thread overview]
Message-ID: <20230201204338.1337562-3-usama.arif@bytedance.com> (raw)
In-Reply-To: <20230201204338.1337562-1-usama.arif@bytedance.com>
From: David Woodhouse <dwmw@amazon.co.uk>
Instead of relying purely on the special-case wrapper in bringup_cpu()
to pass the idle thread to __cpu_up(), expose idle_thread_get() so that
the architecture code can obtain it directly when necessary.
This will be useful when the existing __cpu_up() is split into multiple
phases, only *one* of which will actually need the idle thread.
If the architecture code is to register its new pre-bringup states with
the cpuhp core, having a special-case wrapper to pass extra arguments is
non-trivial and it's easier just to let the arch register its function
pointer to be invoked with the standard API.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
include/linux/smpboot.h | 7 +++++++
kernel/smpboot.h | 2 --
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/linux/smpboot.h b/include/linux/smpboot.h
index 9d1bc65d226c..3862addcaa34 100644
--- a/include/linux/smpboot.h
+++ b/include/linux/smpboot.h
@@ -5,6 +5,13 @@
#include <linux/types.h>
struct task_struct;
+
+#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
+struct task_struct *idle_thread_get(unsigned int cpu);
+#else
+static inline struct task_struct *idle_thread_get(unsigned int cpu) { return NULL; }
+#endif
+
/* Cookie handed to the thread_fn*/
struct smpboot_thread_data;
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 34dd3d7ba40b..60c609318ad6 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -5,11 +5,9 @@
struct task_struct;
#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
-struct task_struct *idle_thread_get(unsigned int cpu);
void idle_thread_set_boot_cpu(void);
void idle_threads_init(void);
#else
-static inline struct task_struct *idle_thread_get(unsigned int cpu) { return NULL; }
static inline void idle_thread_set_boot_cpu(void) { }
static inline void idle_threads_init(void) { }
#endif
--
2.25.1
next prev parent reply other threads:[~2023-02-01 20:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-01 20:43 [PATCH 0/9] Parallel CPU bringup for x86_64 Usama Arif
2023-02-01 20:43 ` [PATCH 1/9] x86/apic/x2apic: Fix parallel handling of cluster_mask Usama Arif
2023-02-01 20:43 ` Usama Arif [this message]
2023-02-01 20:43 ` [PATCH 3/9] cpu/hotplug: Add dynamic parallel bringup states before CPUHP_BRINGUP_CPU Usama Arif
2023-02-01 20:43 ` [PATCH 4/9] x86/smpboot: Reference count on smpboot_setup_warm_reset_vector() Usama Arif
2023-02-01 20:43 ` [PATCH 5/9] x86/smpboot: Split up native_cpu_up into separate phases and document them Usama Arif
2023-02-01 20:43 ` [PATCH 6/9] x86/smpboot: Support parallel startup of secondary CPUs Usama Arif
2023-02-01 20:43 ` [PATCH 7/9] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel Usama Arif
2023-02-01 20:43 ` [PATCH 8/9] x86/mtrr: Avoid repeated save of MTRRs on boot-time CPU bringup Usama Arif
2023-02-01 20:43 ` [PATCH 9/9] x86/smpboot: Serialize topology updates for secondary bringup Usama Arif
2023-02-02 10:02 ` [PATCH 0/9] Parallel CPU bringup for x86_64 David Woodhouse
2023-02-02 21:59 ` Usama Arif
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