This is a note to let you know that I've just added the patch titled
drivers/perf: hisi: Don't migrate perf to the CPU going to teardown
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-perf-hisi-don-t-migrate-perf-to-the-cpu-goin.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5ec63bf0d030098ff0be68f5a89bee45dcd3646c
Author: Junhao He <hejunhao3@xxxxxxxxxx>
Date: Thu Jun 8 19:43:26 2023 +0800
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@xxxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Link: https://lore.kernel.org/r/20230608114326.27649-1-hejunhao3@xxxxxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index 071e63d9a9ac6..b61f1f9aba214 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;
