> On May 10, 2019, at 10:02 PM, Keith Busch <kbu...@kernel.org> wrote: > > On Thu, May 09, 2019 at 11:05:42PM -0700, Kai-Heng Feng wrote: >> Yes, that’ what I was told by the NVMe vendor, so all I know is to impose a >> memory barrier. >> If mb() shouldn’t be used here, what’s the correct variant to use in this >> context? > > I'm afraid the requirement is still not clear to me. AFAIK, all our > barriers routines ensure data is visible either between CPUs, or between > CPU and devices. The CPU never accesses HMB memory, so there must be some > other reasoning if this barrier is a real requirement for this device. Sure, I’ll ask vendor what that MemRd is for. Kai-Heng
- Re: [PATCH] nvme-pci: Use non-operational power state in... Rafael J. Wysocki
- RE: [PATCH] nvme-pci: Use non-operational power state in... Mario.Limonciello
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch
- RE: [PATCH] nvme-pci: Use non-operational power state in... Mario.Limonciello
- Re: [PATCH] nvme-pci: Use non-operational power state in... Kai-Heng Feng
- Re: [PATCH] nvme-pci: Use non-operational power state in... Rafael J. Wysocki
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch
- Re: [PATCH] nvme-pci: Use non-operational power state in... Kai Heng Feng
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch
- Re: [PATCH] nvme-pci: Use non-operational power state in... Kai Heng Feng
- Re: [PATCH] nvme-pci: Use non-operational power state in... h...@lst.de
- Re: [PATCH] nvme-pci: Use non-operational power state in... Christoph Hellwig
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch
- Re: [PATCH] nvme-pci: Use non-operational power state in... Keith Busch