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authorJunhao He <hejunhao3@huawei.com>2023-06-08 19:43:26 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-07-19 16:21:00 +0200
commitbe9c8c9c84b6d25a7b7d39954030aba6f759feb6 (patch)
tree8a2c7add4ac15aa397d4272883d955ef982161b4 /drivers/perf
parent6b025ec148e81edadc51ed219590e16f07eb17a7 (diff)
downloadlinux-be9c8c9c84b6d25a7b7d39954030aba6f759feb6.tar.gz
drivers/perf: hisi: Don't migrate perf to the CPU going to teardown
[ Upstream commit 7a6a9f1c5a0a875a421db798d4b2ee022dc1ee1a ]

The driver needs to migrate the perf context if the current using CPU going
to teardown. By the time calling the cpuhp::teardown() callback the
cpu_online_mask() hasn't updated yet and still includes the CPU going to
teardown. In current driver's implementation we may migrate the context
to the teardown CPU and leads to the below calltrace:

...
[  368.104662][  T932] task:cpuhp/0         state:D stack:    0 pid:   15 ppid:     2 flags:0x00000008
[  368.113699][  T932] Call trace:
[  368.116834][  T932]  __switch_to+0x7c/0xbc
[  368.120924][  T932]  __schedule+0x338/0x6f0
[  368.125098][  T932]  schedule+0x50/0xe0
[  368.128926][  T932]  schedule_preempt_disabled+0x18/0x24
[  368.134229][  T932]  __mutex_lock.constprop.0+0x1d4/0x5dc
[  368.139617][  T932]  __mutex_lock_slowpath+0x1c/0x30
[  368.144573][  T932]  mutex_lock+0x50/0x60
[  368.148579][  T932]  perf_pmu_migrate_context+0x84/0x2b0
[  368.153884][  T932]  hisi_pcie_pmu_offline_cpu+0x90/0xe0 [hisi_pcie_pmu]
[  368.160579][  T932]  cpuhp_invoke_callback+0x2a0/0x650
[  368.165707][  T932]  cpuhp_thread_fun+0xe4/0x190
[  368.170316][  T932]  smpboot_thread_fn+0x15c/0x1a0
[  368.175099][  T932]  kthread+0x108/0x13c
[  368.179012][  T932]  ret_from_fork+0x10/0x18
...

Use function cpumask_any_but() to find one correct active cpu to fixes
this issue.

Fixes: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230608114326.27649-1-hejunhao3@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/perf')
-rw-r--r--drivers/perf/hisilicon/hisi_pcie_pmu.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index 071e63d9a9ac..b61f1f9aba21 100644
--- a/drivers/perf/hisilicon/hisi_pcie_pmu.c
+++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c
@@ -672,7 +672,7 @@ static int hisi_pcie_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
 
 	pcie_pmu->on_cpu = -1;
 	/* Choose a new CPU from all online cpus. */
-	target = cpumask_first(cpu_online_mask);
+	target = cpumask_any_but(cpu_online_mask, cpu);
 	if (target >= nr_cpu_ids) {
 		pci_err(pcie_pmu->pdev, "There is no CPU to set\n");
 		return 0;