[+cc linux-pci] On Thu, Jun 22, 2017 at 12:28:09AM +0200, Thomas Gleixner wrote: > Andi, > > On Mon, 12 Jun 2017, Andi Kleen wrote: > > 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. > > Just rechecked. It still applies and boots (patch 6/7) dropped. > > If Bjorn has no objections I can route it through tip tomorrow. Sorry for the delay. I use patchwork as my to-do list, and it only looks at linux-pci. This series wasn't posted there, so I didn't see it until now. I have a couple trivial comments but I think it looks great overall. Here's my ack if you want to apply it via tip: Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Bjorn
