From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, David Woodhouse <dwmw2@infradead.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Brian Gerst <brgerst@gmail.com>,
Arjan van de Veen <arjan@linux.intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Paul McKenney <paulmck@kernel.org>,
Tom Lendacky <thomas.lendacky@amd.com>,
Sean Christopherson <seanjc@google.com>,
Oleksandr Natalenko <oleksandr@natalenko.name>,
Paul Menzel <pmenzel@molgen.mpg.de>,
"Guilherme G. Piccoli" <gpiccoli@igalia.com>,
Piotr Gorski <lucjan.lucjanov@gmail.com>,
Usama Arif <usama.arif@bytedance.com>,
Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
xen-devel@lists.xenproject.org,
Russell King <linux@armlinux.org.uk>,
Arnd Bergmann <arnd@arndb.de>,
linux-arm-kernel@lists.infradead.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>,
linux-csky@vger.kernel.org,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
linux-mips@vger.kernel.org,
"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
Helge Deller <deller@gmx.de>,
linux-parisc@vger.kernel.org,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
linux-riscv@lists.infradead.org,
Mark Rutland <mark.rutland@arm.com>,
Sabin Rapan <sabrapan@amazon.com>,
"Michael Kelley (LINUX)" <mikelley@microsoft.com>
Subject: [patch v3 13/36] x86/smpboot: Remove cpu_callin_mask
Date: Mon, 8 May 2023 21:43:47 +0200 (CEST) [thread overview]
Message-ID: <20230508185217.956149661@linutronix.de> (raw)
In-Reply-To: 20230508181633.089804905@linutronix.de
From: Thomas Gleixner <tglx@linutronix.de>
Now that TSC synchronization is SMP function call based there is no reason
to wait for the AP to be set in smp_callin_mask. The control CPU waits for
the AP to set itself in the online mask anyway.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
---
arch/x86/kernel/smpboot.c | 61 +++++++---------------------------------------
1 file changed, 10 insertions(+), 51 deletions(-)
---
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -104,7 +104,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_info);
/* All of these masks are initialized in setup_cpu_local_masks() */
static cpumask_var_t cpu_initialized_mask;
static cpumask_var_t cpu_callout_mask;
-static cpumask_var_t cpu_callin_mask;
/* Representing CPUs for which sibling maps can be computed */
static cpumask_var_t cpu_sibling_setup_mask;
@@ -167,21 +166,16 @@ static inline void smpboot_restore_warm_
*/
static void smp_callin(void)
{
- int cpuid;
+ int cpuid = smp_processor_id();
/*
* If waken up by an INIT in an 82489DX configuration
- * cpu_callout_mask guarantees we don't get here before
- * an INIT_deassert IPI reaches our local APIC, so it is
- * now safe to touch our local APIC.
- */
- cpuid = smp_processor_id();
-
- /*
- * the boot CPU has finished the init stage and is spinning
- * on callin_map until we finish. We are free to set up this
- * CPU, first the APIC. (this is probably redundant on most
- * boards)
+ * cpu_callout_mask guarantees we don't get here before an
+ * INIT_deassert IPI reaches our local APIC, so it is now safe to
+ * touch our local APIC.
+ *
+ * Set up this CPU, first the APIC, which is probably redundant on
+ * most boards.
*/
apic_ap_setup();
@@ -192,7 +186,7 @@ static void smp_callin(void)
* The topology information must be up to date before
* calibrate_delay() and notify_cpu_starting().
*/
- set_cpu_sibling_map(raw_smp_processor_id());
+ set_cpu_sibling_map(cpuid);
ap_init_aperfmperf();
@@ -205,11 +199,6 @@ static void smp_callin(void)
* state (CPUHP_ONLINE in the case of serial bringup).
*/
notify_cpu_starting(cpuid);
-
- /*
- * Allow the master to continue.
- */
- cpumask_set_cpu(cpuid, cpu_callin_mask);
}
static void ap_calibrate_delay(void)
@@ -268,11 +257,6 @@ static void notrace start_secondary(void
rcu_cpu_starting(raw_smp_processor_id());
x86_cpuinit.early_percpu_clock_init();
- /*
- * Sync point with wait_cpu_callin(). The AP doesn't wait here
- * but just sets the bit to let the controlling CPU (BSP) know that
- * it's got this far.
- */
smp_callin();
/* Otherwise gcc will move up smp_processor_id() before cpu_init() */
@@ -1112,7 +1096,7 @@ static int wait_cpu_cpumask(unsigned int
* and thus wait_for_master_cpu(), then set cpu_callout_mask to allow it
* to proceed. The AP will then proceed past setting its 'callin' bit
* and end up waiting in check_tsc_sync_target() until we reach
- * do_wait_cpu_online() to tend to it.
+ * wait_cpu_online() to tend to it.
*/
static int wait_cpu_initialized(unsigned int cpu)
{
@@ -1127,20 +1111,7 @@ static int wait_cpu_initialized(unsigned
}
/*
- * Bringup step three: Wait for the target AP to reach smp_callin().
- * The AP is not waiting for us here so we don't need to parallelise
- * this step. Not entirely clear why we care about this, since we just
- * proceed directly to TSC synchronization which is the next sync
- * point with the AP anyway.
- */
-static void wait_cpu_callin(unsigned int cpu)
-{
- while (!cpumask_test_cpu(cpu, cpu_callin_mask))
- schedule();
-}
-
-/*
- * Bringup step four: Wait for the target AP to reach set_cpu_online() in
+ * Bringup step three: Wait for the target AP to reach set_cpu_online() in
* start_secondary().
*/
static void wait_cpu_online(unsigned int cpu)
@@ -1170,14 +1141,6 @@ static int native_kick_ap(unsigned int c
}
/*
- * Already booted CPU?
- */
- if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
- pr_debug("do_boot_cpu %d Already started\n", cpu);
- return -ENOSYS;
- }
-
- /*
* Save current MTRR state in case it was changed since early boot
* (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
*/
@@ -1214,7 +1177,6 @@ int native_cpu_up(unsigned int cpu, stru
if (ret)
goto out;
- wait_cpu_callin(cpu);
wait_cpu_online(cpu);
out:
@@ -1330,7 +1292,6 @@ void __init smp_prepare_cpus_common(void
* Setup boot CPU information
*/
smp_store_boot_cpu_info(); /* Final full version of the data */
- cpumask_copy(cpu_callin_mask, cpumask_of(0));
mb();
for_each_possible_cpu(i) {
@@ -1545,7 +1506,6 @@ early_param("possible_cpus", _setup_poss
void __init setup_cpu_local_masks(void)
{
alloc_bootmem_cpumask_var(&cpu_initialized_mask);
- alloc_bootmem_cpumask_var(&cpu_callin_mask);
alloc_bootmem_cpumask_var(&cpu_callout_mask);
alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask);
}
@@ -1609,7 +1569,6 @@ static void remove_cpu_from_maps(int cpu
{
set_cpu_online(cpu, false);
cpumask_clear_cpu(cpu, cpu_callout_mask);
- cpumask_clear_cpu(cpu, cpu_callin_mask);
/* was set by cpu_init() */
cpumask_clear_cpu(cpu, cpu_initialized_mask);
numa_remove_cpu(cpu);
next prev parent reply other threads:[~2023-05-08 19:44 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-08 19:43 [patch v3 00/36] cpu/hotplug, x86: Reworked parallel CPU bringup Thomas Gleixner
2023-05-08 19:43 ` [patch v3 01/36] [patch V2 01/38] x86/smpboot: Cleanup topology_phys_to_logical_pkg()/die() Thomas Gleixner
2023-05-08 19:43 ` [patch v3 02/36] cpu/hotplug: Mark arch_disable_smp_support() and bringup_nonboot_cpus() __init Thomas Gleixner
2023-05-08 19:43 ` [patch v3 03/36] x86/smpboot: Avoid pointless delay calibration if TSC is synchronized Thomas Gleixner
2023-05-08 19:43 ` [patch v3 04/36] x86/smpboot: Rename start_cpu0() to soft_restart_cpu() Thomas Gleixner
2023-05-08 19:43 ` [patch v3 05/36] x86/topology: Remove CPU0 hotplug option Thomas Gleixner
2023-05-08 19:43 ` [patch v3 06/36] x86/smpboot: Remove the CPU0 hotplug kludge Thomas Gleixner
2023-05-08 19:43 ` [patch v3 07/36] x86/smpboot: Restrict soft_restart_cpu() to SEV Thomas Gleixner
2023-05-08 19:43 ` [patch v3 08/36] x86/smpboot: Split up native_cpu_up() into separate phases and document them Thomas Gleixner
2023-05-09 10:04 ` Peter Zijlstra
2023-05-09 12:07 ` Thomas Gleixner
2023-05-09 17:59 ` Thomas Gleixner
2023-05-09 20:11 ` Thomas Gleixner
2023-05-10 8:39 ` Peter Zijlstra
2023-05-09 10:19 ` Peter Zijlstra
2023-05-09 12:08 ` Thomas Gleixner
2023-05-09 18:03 ` Thomas Gleixner
2023-05-09 10:31 ` Peter Zijlstra
2023-05-09 12:09 ` Thomas Gleixner
2023-05-08 19:43 ` [patch v3 09/36] x86/smpboot: Get rid of cpu_init_secondary() Thomas Gleixner
2023-05-08 19:43 ` [patch v3 10/36] [patch V2 10/38] x86/cpu/cacheinfo: Remove cpu_callout_mask dependency Thomas Gleixner
2023-05-08 19:43 ` [patch v3 11/36] [patch V2 11/38] x86/smpboot: Move synchronization masks to SMP boot code Thomas Gleixner
2023-05-08 19:43 ` [patch v3 12/36] [patch V2 12/38] x86/smpboot: Make TSC synchronization function call based Thomas Gleixner
2023-05-08 19:43 ` Thomas Gleixner [this message]
2023-05-09 10:49 ` [patch v3 13/36] x86/smpboot: Remove cpu_callin_mask Peter Zijlstra
2023-05-09 12:09 ` Thomas Gleixner
2023-05-08 19:43 ` [patch v3 14/36] [patch V2 14/38] cpu/hotplug: Rework sparse_irq locking in bringup_cpu() Thomas Gleixner
2023-05-09 11:02 ` Peter Zijlstra
2023-05-09 12:10 ` Thomas Gleixner
2023-05-08 19:43 ` [patch v3 15/36] x86/smpboot: Remove wait for cpu_online() Thomas Gleixner
2023-05-08 19:43 ` [patch v3 16/36] x86/xen/smp_pv: Remove wait for CPU online Thomas Gleixner
2023-05-08 19:43 ` [patch v3 17/36] x86/xen/hvm: Get rid of DEAD_FROZEN handling Thomas Gleixner
2023-05-08 19:43 ` [patch v3 18/36] [patch V2 18/38] cpu/hotplug: Add CPU state tracking and synchronization Thomas Gleixner
2023-05-09 11:07 ` Peter Zijlstra
2023-05-09 11:35 ` Peter Zijlstra
2023-05-09 12:12 ` Thomas Gleixner
2023-05-08 19:43 ` [patch v3 19/36] x86/smpboot: Switch to hotplug core state synchronization Thomas Gleixner
2023-05-08 19:43 ` [patch v3 20/36] cpu/hotplug: Remove cpu_report_state() and related unused cruft Thomas Gleixner
2023-05-08 19:44 ` [patch v3 21/36] [patch V2 21/38] ARM: smp: Switch to hotplug core state synchronization Thomas Gleixner
2023-05-08 19:44 ` [patch v3 22/36] arm64: " Thomas Gleixner
2023-05-08 19:44 ` [patch v3 23/36] [patch V2 23/38] csky/smp: " Thomas Gleixner
2023-05-08 19:44 ` [patch v3 24/36] [patch V2 24/38] MIPS: SMP_CPS: " Thomas Gleixner
2023-05-08 19:44 ` [patch v3 25/36] parisc: " Thomas Gleixner
2023-05-08 19:44 ` [patch v3 26/36] riscv: " Thomas Gleixner
2023-05-08 19:44 ` [patch v3 27/36] cpu/hotplug: Remove unused state functions Thomas Gleixner
2023-05-08 19:44 ` [patch v3 28/36] cpu/hotplug: Reset task stack state in _cpu_up() Thomas Gleixner
2023-05-08 19:44 ` [patch v3 29/36] [patch V2 29/38] cpu/hotplug: Provide a split up CPUHP_BRINGUP mechanism Thomas Gleixner
2023-05-08 19:44 ` [patch v3 30/36] x86/smpboot: Enable split CPU startup Thomas Gleixner
2023-05-08 19:44 ` [patch v3 31/36] x86/apic: Provide cpu_primary_thread mask Thomas Gleixner
2023-05-24 20:48 ` Kirill A. Shutemov
2023-05-26 10:14 ` Thomas Gleixner
2023-05-27 13:40 ` Thomas Gleixner
2023-05-29 2:39 ` Kirill A. Shutemov
2023-05-29 19:27 ` Thomas Gleixner
2023-05-29 20:31 ` Kirill A. Shutemov
2023-05-30 0:54 ` Kirill A. Shutemov
2023-05-30 9:26 ` Thomas Gleixner
2023-05-30 10:34 ` Thomas Gleixner
2023-05-30 11:37 ` Kirill A. Shutemov
2023-05-30 12:09 ` [patch] x86/smpboot: Disable parallel bootup if cc_vendor != NONE Thomas Gleixner
2023-05-30 12:29 ` Kirill A. Shutemov
2023-05-30 16:00 ` Thomas Gleixner
2023-05-30 16:56 ` Sean Christopherson
2023-05-30 19:51 ` Thomas Gleixner
2023-05-30 20:03 ` Tom Lendacky
2023-05-30 20:39 ` Thomas Gleixner
2023-05-30 21:13 ` Tom Lendacky
2023-05-31 7:44 ` [patch] x86/smpboot: Fix the parallel bringup decision Thomas Gleixner
2023-05-31 11:07 ` Kirill A. Shutemov
2023-05-31 13:58 ` Tom Lendacky
2023-05-30 17:02 ` [patch] x86/smpboot: Disable parallel bootup if cc_vendor != NONE Kirill A. Shutemov
2023-05-30 17:31 ` Sean Christopherson
2023-05-30 9:26 ` [patch v3 31/36] x86/apic: Provide cpu_primary_thread mask Thomas Gleixner
2023-05-30 10:46 ` [patch] x86/realmode: Make stack lock work in trampoline_compat() Thomas Gleixner
2023-05-30 11:12 ` Kirill A. Shutemov
2023-06-08 23:34 ` Yunhong Jiang
2023-06-08 23:57 ` Andrew Cooper
2023-06-09 0:22 ` Yunhong Jiang
2023-06-10 19:50 ` David Laight
2023-06-10 22:51 ` 'Andrew Cooper'
2023-05-08 19:44 ` [patch v3 32/36] cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE Thomas Gleixner
2023-05-08 19:44 ` [patch v3 33/36] x86/apic: Save the APIC virtual base address Thomas Gleixner
2023-05-09 9:20 ` Sergey Shtylyov
2023-05-08 19:44 ` [patch v3 34/36] x86/smpboot: Implement a bit spinlock to protect the realmode stack Thomas Gleixner
2023-05-09 13:13 ` Peter Zijlstra
2023-05-09 13:47 ` Thomas Gleixner
2023-05-08 19:44 ` [patch v3 35/36] x86/smpboot: Support parallel startup of secondary CPUs Thomas Gleixner
2023-05-09 13:57 ` Peter Zijlstra
2023-05-08 19:44 ` [patch v3 36/36] x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it Thomas Gleixner
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