Messages in this thread | | | Date | Mon, 12 Jun 2017 17:25:36 -0700 | From | Andi Kleen <> | Subject | Re: [patch 0/7] x86/pci: Switch to lockless ECAM configuration mode |
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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
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