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| author | Yicong Yang <yangyicong@hisilicon.com> | 2023-06-21 11:28:04 +0200 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2023-06-21 12:52:39 +0200 |
| commit | 6c50384ef8b94a527445e3694ae6549e1f15d859 (patch) | |
| tree | 81afd8e02ddbee9736d8fb35f322d654f81d497e /Documentation/trace | |
| parent | hwtracing: hisi_ptt: Advertise PERF_PMU_CAP_NO_EXCLUDE for PTT PMU (diff) | |
| download | linux-6c50384ef8b94a527445e3694ae6549e1f15d859.tar.xz linux-6c50384ef8b94a527445e3694ae6549e1f15d859.zip | |
hwtracing: hisi_ptt: Fix potential sleep in atomic context
We're using pci_irq_vector() to obtain the interrupt number and then
bind it to the CPU start perf under the protection of spinlock in
pmu::start(). pci_irq_vector() might sleep since [1] because it will
call msi_domain_get_virq() to get the MSI interrupt number and it
needs to acquire dev->msi.data->mutex. Getting a mutex will sleep on
contention. So use pci_irq_vector() in an atomic context is problematic.
This patch cached the interrupt number in the probe() and uses the
cached data instead to avoid potential sleep.
[1] commit 82ff8e6b78fc ("PCI/MSI: Use msi_get_virq() in pci_get_vector()")
Fixes: ff0de066b463 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230621092804.15120-6-yangyicong@huawei.com
Diffstat (limited to 'Documentation/trace')
0 files changed, 0 insertions, 0 deletions