Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Yuan ZhaoXiong <yuanzhx326@gmail.com>
To:     tglx@linutronix.de, steven.price@arm.com, Jason@zx2c4.com,
        juri.lelli@redhat.com, tony.luck@intel.com, frederic@kernel.org,
        yuanzhx326@gmail.com, sathyanarayanan.kuppuswamy@linux.intel.com
Cc:     linux-kernel@vger.kernel.org
Subject: [PATCH] cpu: printk error information when call cpu_up() failed.
Date:   Mon, 28 Nov 2022 21:28:03 +0800
Message-Id: <20221128132803.17599-1-yuanzhx326@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

It is better to printk error information out when calling cpu_up() failed.
Users will observe cpu up error conveniently via the kernel log.

Signed-off-by: Yuan ZhaoXiong <yuanzhx326@gmail.com>
---
 kernel/cpu.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index bbad5e375d3b..28b0202e7744 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1481,12 +1481,16 @@ int bringup_hibernate_cpu(unsigned int sleep_cpu)
 void bringup_nonboot_cpus(unsigned int setup_max_cpus)
 {
 	unsigned int cpu;
+	int error;
 
 	for_each_present_cpu(cpu) {
 		if (num_online_cpus() >= setup_max_cpus)
 			break;
-		if (!cpu_online(cpu))
-			cpu_up(cpu, CPUHP_ONLINE);
+		if (!cpu_online(cpu)) {
+			error = cpu_up(cpu, CPUHP_ONLINE);
+			if (error)
+				pr_err("Error taking CPU%d up: %d\n", cpu, error);
+		}
 	}
 }
 
-- 
2.27.0