From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Will Deacon <will@kernel.org>, Qian Cai <cai@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Sasha Levin <sashal@kernel.org>,
linux-arm-kernel@lists.infradead.org, rcu@vger.kernel.org
Subject: [PATCH AUTOSEL 5.9 12/21] arm64: smp: Tell RCU about CPUs that fail to come online
Date: Tue, 17 Nov 2020 07:56:43 -0500 [thread overview]
Message-ID: <20201117125652.599614-12-sashal@kernel.org> (raw)
In-Reply-To: <20201117125652.599614-1-sashal@kernel.org>
From: Will Deacon <will@kernel.org>
[ Upstream commit 04e613ded8c26489b3e0f9101b44462f780d1a35 ]
Commit ce3d31ad3cac ("arm64/smp: Move rcu_cpu_starting() earlier") ensured
that RCU is informed early about incoming CPUs that might end up calling
into printk() before they are online. However, if such a CPU fails the
early CPU feature compatibility checks in check_local_cpu_capabilities(),
then it will be powered off or parked without informing RCU, leading to
an endless stream of stalls:
| rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
| rcu: 2-O...: (0 ticks this GP) idle=002/1/0x4000000000000000 softirq=0/0 fqs=2593
| (detected by 0, t=5252 jiffies, g=9317, q=136)
| Task dump for CPU 2:
| task:swapper/2 state:R running task stack: 0 pid: 0 ppid: 1 flags:0x00000028
| Call trace:
| ret_from_fork+0x0/0x30
Ensure that the dying CPU invokes rcu_report_dead() prior to being powered
off or parked.
Cc: Qian Cai <cai@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Suggested-by: Qian Cai <cai@redhat.com>
Link: https://lore.kernel.org/r/20201105222242.GA8842@willie-the-truck
Link: https://lore.kernel.org/r/20201106103602.9849-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/kernel/smp.c | 1 +
kernel/rcu/tree.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 98c059b6bacae..361cfc55cf5a7 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -401,6 +401,7 @@ void cpu_die_early(void)
/* Mark this CPU absent */
set_cpu_present(cpu, 0);
+ rcu_report_dead(cpu);
if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
update_cpu_boot_status(CPU_KILL_ME);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index c8f62e2d02761..b4924fefe2745 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -4024,7 +4024,6 @@ void rcu_cpu_starting(unsigned int cpu)
smp_mb(); /* Ensure RCU read-side usage follows above initialization. */
}
-#ifdef CONFIG_HOTPLUG_CPU
/*
* The outgoing function has no further need of RCU, so remove it from
* the rcu_node tree's ->qsmaskinitnext bit masks.
@@ -4064,6 +4063,7 @@ void rcu_report_dead(unsigned int cpu)
per_cpu(rcu_cpu_started, cpu) = 0;
}
+#ifdef CONFIG_HOTPLUG_CPU
/*
* The outgoing CPU has just passed through the dying-idle state, and we
* are being invoked from the CPU that was IPIed to continue the offline
--
2.27.0
next prev parent reply other threads:[~2020-11-17 12:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-17 12:56 [PATCH AUTOSEL 5.9 01/21] Revert "Revert "gpio: omap: Fix lost edge wake-up interrupts"" Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 02/21] tools, bpftool: Avoid array index warnings Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 03/21] habanalabs/gaudi: mask WDT error in QMAN Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 04/21] pinctrl: rockchip: enable gpio pclk for rockchip_gpio_to_irq Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 05/21] scsi: ufs: Fix unbalanced scsi_block_reqs_cnt caused by ufshcd_hold() Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 06/21] scsi: ufs: Try to save power mode change and UIC cmd completion timeout Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 07/21] pinctrl: mcp23s08: Print error message when regmap init fails Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 08/21] selftests: kvm: Fix the segment descriptor layout to match the actual layout Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 09/21] ACPI: button: Add DMI quirk for Medion Akoya E2228T Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 10/21] arm64: errata: Fix handling of 1418040 with late CPU onlining Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 11/21] arm64: psci: Avoid printing in cpu_psci_cpu_die() Sasha Levin
2020-11-17 12:56 ` Sasha Levin [this message]
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 13/21] lockdep: Avoid to modify chain keys in validate_chain() Sasha Levin
2020-11-18 1:26 ` Boqun Feng
2020-11-19 1:22 ` Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 14/21] um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb() Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 15/21] vfs: remove lockdep bogosity in __sb_start_write Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 16/21] gfs2: fix possible reference leak in gfs2_check_blk_type Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 17/21] hwmon: (pwm-fan) Fix RPM calculation Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 18/21] gfs2: Fix case in which ail writes are done to jdata holes Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 19/21] arm64: Add MIDR value for KRYO2XX gold/silver CPU cores Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 20/21] arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist Sasha Levin
2020-11-17 12:56 ` [PATCH AUTOSEL 5.9 21/21] arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver Sasha Levin
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