The following commit has been merged into the x86/core branch of tip:
Commit-ID: 5cb5f5acb01749db1b878ea054a00aac13e59fdb
Gitweb: https://git.kernel.org/tip/5cb5f5acb01749db1b878ea054a00aac13e59fdb
Author: Brian Gerst <brgerst@xxxxxxxxx>
AuthorDate: Mon, 03 Mar 2025 11:52:39 -05:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 04 Mar 2025 20:18:02 +01:00
x86/smp: Move cpu number to percpu hot section
No functional change.
Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250303165246.2175811-5-brgerst@xxxxxxxxx
---
arch/x86/include/asm/current.h | 1 -
arch/x86/include/asm/smp.h | 7 ++++---
arch/x86/kernel/setup_percpu.c | 5 ++++-
kernel/bpf/verifier.c | 4 ++--
4 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h
index 46a736d..f988462 100644
--- a/arch/x86/include/asm/current.h
+++ b/arch/x86/include/asm/current.h
@@ -14,7 +14,6 @@ struct task_struct;
struct pcpu_hot {
struct task_struct *current_task;
- int cpu_number;
#ifdef CONFIG_MITIGATION_CALL_DEPTH_TRACKING
u64 call_depth;
#endif
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 76d7c01..bcfa002 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -6,7 +6,8 @@
#include <linux/thread_info.h>
#include <asm/cpumask.h>
-#include <asm/current.h>
+
+DECLARE_PER_CPU_CACHE_HOT(int, cpu_number);
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
@@ -132,8 +133,8 @@ __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.
*/
-#define raw_smp_processor_id() this_cpu_read(pcpu_hot.cpu_number)
-#define __smp_processor_id() __this_cpu_read(pcpu_hot.cpu_number)
+#define raw_smp_processor_id() this_cpu_read(cpu_number)
+#define __smp_processor_id() __this_cpu_read(cpu_number)
static inline struct cpumask *cpu_llc_shared_mask(int cpu)
{
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 1e7be94..175afc3 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -23,6 +23,9 @@
#include <asm/cpumask.h>
#include <asm/cpu.h>
+DEFINE_PER_CPU_CACHE_HOT(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
EXPORT_PER_CPU_SYMBOL(this_cpu_off);
@@ -161,7 +164,7 @@ 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(pcpu_hot.cpu_number, cpu) = cpu;
+ per_cpu(cpu_number, cpu) = cpu;
setup_percpu_segment(cpu);
/*
* Copy data used in early init routines from the
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f485951..6e604ca 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -21702,12 +21702,12 @@ patch_map_ops_generic:
if (insn->imm == BPF_FUNC_get_smp_processor_id &&
verifier_inlines_helper_call(env, insn->imm)) {
/* BPF_FUNC_get_smp_processor_id inlining is an
- * optimization, so if pcpu_hot.cpu_number is ever
+ * optimization, so if cpu_number is ever
* changed in some incompatible and hard to support
* way, it's fine to back out this inlining logic
*/
#ifdef CONFIG_SMP
- insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number);
+ insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, (u32)(unsigned long)&cpu_number);
insn_buf[1] = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0);
insn_buf[2] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0);
cnt = 3;
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