On Thu, Mar 16, 2017 at 10:50:02PM +0100, Thomas Gleixner wrote: > Andi reported that the Intel Uncore performance monitoring suffers from the > global pci_lock which protects the generic PCI config space accessors. > > This lock can be removed on X86 because all architecture specific config > space accessors are either serialized by a seperate lock or can be > converted to have their own locking. The mmconfig based access (ECAM) does > not require serialization at the config read/write level because the access > is a simple byte/word/dword read from or write to the memory mapped > configuration space. In that case the lock does not provide any more > protection than the hardware provides already. > > The series converts the CE4100 PCI low level accessors to use the x86 > specific pci_config_lock and implements the switch over to lockless ECAM > configureation space accesors when the system is capable.
What's the status of this patch series? The lock contention problem is still there. Thanks, -Andi
