linux-kernel - [tip: x86/core] x86/percpu: Move cpu_number next to current

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <166601844759.401.13692031213391443378.tip-bot2@tip-bot2>
Date:   Mon, 17 Oct 2022 14:54:07 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/core] x86/percpu: Move cpu_number next to current_task

The following commit has been merged into the x86/core branch of tip:

Commit-ID:     7443b296e699e6922f5be243c8d2e316de8cacbe
Gitweb:        https://git.kernel.org/tip/7443b296e699e6922f5be243c8d2e316de8cacbe
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Thu, 15 Sep 2022 13:11:03 +02:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Mon, 17 Oct 2022 16:41:04 +02:00

x86/percpu: Move cpu_number next to current_task

Also add cpu_number to the pcpu_hot structure, it is often referenced
and this cacheline is there.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lore.kernel.org/r/20220915111145.387678283@infradead.org
---
 arch/x86/include/asm/current.h |  1 +
 arch/x86/include/asm/smp.h     | 12 +++++-------
 arch/x86/kernel/setup_percpu.c |  5 +----
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h
index 0f4b462..8ac6589 100644
--- a/arch/x86/include/asm/current.h
+++ b/arch/x86/include/asm/current.h
@@ -16,6 +16,7 @@ struct pcpu_hot {
 		struct {
 			struct task_struct	*current_task;
 			int			preempt_count;
+			int			cpu_number;
 		};
 		u8	pad[64];
 	};
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index a73bced..b4dbb20 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -3,10 +3,10 @@
 #define _ASM_X86_SMP_H
 #ifndef __ASSEMBLY__
 #include <linux/cpumask.h>
-#include <asm/percpu.h>
 
-#include <asm/thread_info.h>
 #include <asm/cpumask.h>
+#include <asm/current.h>
+#include <asm/thread_info.h>
 
 extern int smp_num_siblings;
 extern unsigned int num_processors;
@@ -19,7 +19,6 @@ DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map);
 DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id);
 DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_l2c_id);
-DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
 
 DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid);
 DECLARE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid);
@@ -150,11 +149,10 @@ __visible void smp_call_function_single_interrupt(struct pt_regs *r);
 
 /*
  * This function is needed by all SMP systems. It must _always_ be valid
- * from the initial startup. We map APIC_BASE very early in page_setup(),
- * so this is correct in the x86 case.
+ * from the initial startup.
  */
-#define raw_smp_processor_id()  this_cpu_read(cpu_number)
-#define __smp_processor_id() __this_cpu_read(cpu_number)
+#define raw_smp_processor_id()  this_cpu_read(pcpu_hot.cpu_number)
+#define __smp_processor_id() __this_cpu_read(pcpu_hot.cpu_number)
 
 #ifdef CONFIG_X86_32
 extern int safe_smp_processor_id(void);
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 555089a..c2fc4c4 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -23,9 +23,6 @@
 #include <asm/cpu.h>
 #include <asm/stackprotector.h>
 
-DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
-EXPORT_PER_CPU_SYMBOL(cpu_number);
-
 #ifdef CONFIG_X86_64
 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
 #else
@@ -172,7 +169,7 @@ void __init setup_per_cpu_areas(void)
 	for_each_possible_cpu(cpu) {
 		per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
 		per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
-		per_cpu(cpu_number, cpu) = cpu;
+		per_cpu(pcpu_hot.cpu_number, cpu) = cpu;
 		setup_percpu_segment(cpu);
 		/*
 		 * Copy data used in early init routines from the