Re: [RFC PATCH v3 1/2] mempinfd: Add new syscall to provide memory pin

From
Jason Gunthorpe <jgg@ziepe.ca>
Date
2021-02-10 18:15:46
Also in
linux-api, linux-iommu, linux-mm, lkml
Reply to
Song Bao Hua (Barry Song), 2021-02-10
On Tue, Feb 09, 2021 at 10:22:47PM +0000, Song Bao Hua (Barry Song) wrote:
The problem is that SVA declares we can use any memory of a process
to do I/O. And in real scenarios, we are unable to customize most
applications to make them use the pool. So we are looking for some
extension generically for applications such as Nginx, Ceph.
But those applications will suffer jitter even if their are using CPU
to do the same work. I fail to see why adding an accelerator suddenly
means the application owner will care about jitter introduced by
migration/etc.

Again in proper SVA it should be quite unlikely to take a fault caused
by something like migration, on the same likelyhood as the CPU. If
things are faulting so much this is a problem then I think it is a
system level problem with doing too much page motion.

Jason

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Thread (33 messages) 33 messages, 9 authors, last reply 2021-02-11
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