[PATCH 0/2] riscv: smp: Two minor comment updates

[PATCH 0/2] riscv: smp: Two minor comment updates

[Vivian Wang]

I happened to be digging around these bits and saw these comments that
confused me for a sec. So, might as well update them for the sake of
future readers.

---
Vivian Wang (2):
      riscv: smp: Remove outdated comment about disabling preemption
      riscv: smp: Clarify comment "cache" -> "instruction cache"

 arch/riscv/kernel/smpboot.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20260204-riscv-smp-comment-update-2026-01-7e75e3a2261a

Best regards,
-- 
Vivian "dramforever" Wang


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH 1/2] riscv: smp: Remove outdated comment about disabling preemption

[Vivian Wang]

Commit f1a0a376ca0c ("sched/core: Initialize the idle task with
preemption disabled") removed a call to preempt_disable(), but not the
associated comment. Remove the outdated comment.

Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled")
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
---
 arch/riscv/kernel/smpboot.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index d85916a3660c..0e6fe20c69a2 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -259,10 +259,6 @@ asmlinkage __visible void smp_callin(void)
 #ifndef CONFIG_HOTPLUG_PARALLEL
 	complete(&cpu_running);
 #endif
-	/*
-	 * Disable preemption before enabling interrupts, so we don't try to
-	 * schedule a CPU that hasn't actually started yet.
-	 */
 	local_irq_enable();
 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 }

-- 
2.52.0


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH 2/2] riscv: smp: Clarify comment "cache" -> "instruction cache"

[Vivian Wang]

local_flush_icache_all() only flushes and synchronizes the *instruction*
cache, not the data cache. Since RISC-V does have a cbo.flush
instruction for data cache flush, clarify the comment to avoid
confusion.

Fixes: 58661a30f1bc ("riscv: Flush the instruction cache during SMP bringup")
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
---
 arch/riscv/kernel/smpboot.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index 0e6fe20c69a2..8b628580fe11 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -251,8 +251,8 @@ asmlinkage __visible void smp_callin(void)
 	set_cpu_online(curr_cpuid, true);
 
 	/*
-	 * Remote cache and TLB flushes are ignored while the CPU is offline,
-	 * so flush them both right now just in case.
+	 * Remote instruction cache and TLB flushes are ignored while the CPU
+	 * is offline, so flush them both right now just in case.
 	 */
 	local_flush_icache_all();
 	local_flush_tlb_all();

-- 
2.52.0


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH 0/2] riscv: smp: Two minor comment updates

[Paul Walmsley]

On Wed, 4 Feb 2026, Vivian Wang wrote:

> I happened to be digging around these bits and saw these comments that 
> confused me for a sec. So, might as well update them for the sake of 
> future readers.

Thanks, queued for v7.0-rc.


- Paul

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv