[PATCH v3 2/2] riscv: add HARDLOCKUP_DETECTOR_PERF support

Yunhui Cui posted 2 patches 2 months, 1 week ago
There is a newer version of this series
[PATCH v3 2/2] riscv: add HARDLOCKUP_DETECTOR_PERF support
Posted by Yunhui Cui 2 months, 1 week ago
Enable the HARDLOCKUP_DETECTOR_PERF function based on RISC-V SSE.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
---
 arch/riscv/Kconfig           |  4 ++++
 drivers/perf/riscv_pmu_sbi.c | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index badbb2b366946..6a7b4d2517c4b 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -186,6 +186,10 @@ config RISCV
 	select HAVE_PAGE_SIZE_4KB
 	select HAVE_PCI
 	select HAVE_PERF_EVENTS
+	select HAVE_PERF_EVENTS_NMI if RISCV_PMU_SBI_SSE
+	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
+	select WATCHDOG_PERF_ADJUST_PERIOD if HARDLOCKUP_DETECTOR_PERF && \
+	CPU_FREQ
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index c852f64a50221..0c7c5924687c9 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -22,6 +22,7 @@
 #include <linux/sched/clock.h>
 #include <linux/soc/andes/irq.h>
 #include <linux/workqueue.h>
+#include <linux/nmi.h>
 
 #include <asm/errata_list.h>
 #include <asm/sbi.h>
@@ -1192,6 +1193,13 @@ static int pmu_sbi_setup_sse(struct riscv_pmu *pmu)
 }
 #endif
 
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+bool arch_perf_nmi_is_available(void)
+{
+	return IS_ENABLED(CONFIG_RISCV_PMU_SBI_SSE);
+}
+#endif
+
 static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node)
 {
 	struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node);
@@ -1618,6 +1626,8 @@ static int __init pmu_sbi_devinit(void)
 	/* Notify legacy implementation that SBI pmu is available*/
 	riscv_pmu_legacy_skip_init();
 
+	lockup_detector_retry_init();
+
 	return ret;
 }
 device_initcall(pmu_sbi_devinit)
-- 
2.39.5
Re: [PATCH v3 2/2] riscv: add HARDLOCKUP_DETECTOR_PERF support
Posted by Paul Walmsley 2 months ago
Hi Yunhui,

On Thu, 9 Oct 2025, Yunhui Cui wrote:

> Enable the HARDLOCKUP_DETECTOR_PERF function based on RISC-V SSE.
> 
> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>

Looks reasonable to me.  I do like Doug Anderson's feedback about avoiding 
the line continuation in arch/riscv/Kconfig/ ; we already have other lines 
that are longer than 80 characters there.

If you wouldn't mind fixing that, then:

Acked-by: Paul Walmsley <pjw@kernel.org>  # for arch/riscv


- Paul
Re: [PATCH v3 2/2] riscv: add HARDLOCKUP_DETECTOR_PERF support
Posted by Doug Anderson 2 months ago
Hi,

On Wed, Oct 8, 2025 at 8:29 PM Yunhui Cui <cuiyunhui@bytedance.com> wrote:
>
> Enable the HARDLOCKUP_DETECTOR_PERF function based on RISC-V SSE.
>
> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
> ---
>  arch/riscv/Kconfig           |  4 ++++
>  drivers/perf/riscv_pmu_sbi.c | 10 ++++++++++
>  2 files changed, 14 insertions(+)

Reviewed-by: Douglas Anderson <dianders@chromium.org>