From 714fe383d6c9bd95d0d2cad8cbeff3688342d025 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 16 Mar 2017 22:50:06 +0100 Subject: PCI: Provide Kconfig option for lockless config space accessors The generic PCI configuration space accessors are globally serialized via pci_lock. On larger systems this causes massive lock contention when the configuration space has to be accessed frequently. One such access pattern is the Intel Uncore performance counter unit. Provide a kernel config option which can be selected by an architecture when the low level PCI configuration space accessors in the architecture use their own serialization or can operate completely lockless. Signed-off-by: Thomas Gleixner Acked-by: Bjorn Helgaas Cc: Andi Kleen Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Borislav Petkov Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/20170316215057.205961140@linutronix.de Signed-off-by: Thomas Gleixner --- drivers/pci/Kconfig | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/pci/Kconfig') diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index e0cacb7b8563..c32a77fc8b03 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -86,6 +86,9 @@ config PCI_ATS config PCI_ECAM bool +config PCI_LOCKLESS_CONFIG + bool + config PCI_IOV bool "PCI IOV support" depends on PCI -- cgit v1.2.3