RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-02-01 Thread Song Bao Hua (Barry Song)
; > iommu@lists.linux-foundation.org; linux...@kvack.org; Zhangfei Gao > ; Liguozhu (Kenneth) ; > linux-accelerat...@lists.ozlabs.org > Subject: RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > > From: Jason Gunthorpe > > Sent: Tuesday, February 2, 2021 7:44 AM > &

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-02-01 Thread Tian, Kevin
> From: Jason Gunthorpe > Sent: Tuesday, February 2, 2021 7:44 AM > > On Fri, Jan 29, 2021 at 10:09:03AM +, Tian, Kevin wrote: > > > SVA is not doom to work with IO page fault only. If we have SVA+pin, > > > we would get both sharing address and stable I/O latency. > > > > Isn't it like a

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-02-01 Thread Song Bao Hua (Barry Song)
sts.linux-foundation.org; linux...@kvack.org; Zhangfei Gao > ; Liguozhu (Kenneth) ; > linux-accelerat...@lists.ozlabs.org > Subject: Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > On Fri, Jan 29, 2021 at 10:09:03AM +, Tian, Kevin wrote: > > > SVA is not doom to

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-02-01 Thread Jason Gunthorpe
On Fri, Jan 29, 2021 at 10:09:03AM +, Tian, Kevin wrote: > > SVA is not doom to work with IO page fault only. If we have SVA+pin, > > we would get both sharing address and stable I/O latency. > > Isn't it like a traditional MAP_DMA API (imply pinning) plus specifying > cpu_va of the memory

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-29 Thread Song Bao Hua (Barry Song)
l.org; iommu@lists.linux-foundation.org; > linux...@kvack.org; Zhangfei Gao ; Liguozhu > (Kenneth) ; linux-accelerat...@lists.ozlabs.org > Subject: RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > > From: Song Bao Hua (Barry Song) > > Sent: Tuesday, January 26, 2021 9:27 AM

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-29 Thread Tian, Kevin
hou (B) ; Greg Kroah-Hartman > > ; Arnd Bergmann ; > Zhangfei Gao > > ; linux-accelerat...@lists.ozlabs.org; > > linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; > > linux...@kvack.org; Liguozhu (Kenneth) ; > chensihang > > (A) > > Subject: Re: [RFC

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-27 Thread Song Bao Hua (Barry Song)
labs.org; > linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; > linux...@kvack.org; Liguozhu (Kenneth) ; chensihang > (A) > Subject: Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > On Tue, Jan 26, 2021 at 01:26:45AM +, Song Bao Hua (Barry Song) wrote: > > > On

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-26 Thread Jason Gunthorpe
On Tue, Jan 26, 2021 at 01:26:45AM +, Song Bao Hua (Barry Song) wrote: > > On Mon, Jan 25, 2021 at 11:35:22PM +, Song Bao Hua (Barry Song) wrote: > > > > > > On Mon, Jan 25, 2021 at 10:21:14PM +, Song Bao Hua (Barry Song) > > > > wrote: > > > > > mlock, while certainly be able to

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-26 Thread Zhou Wang
On 2021/1/25 23:47, Jason Gunthorpe wrote: > On Mon, Jan 25, 2021 at 04:34:56PM +0800, Zhou Wang wrote: > >> +static int uacce_pin_page(struct uacce_pin_container *priv, >> + struct uacce_pin_address *addr) >> +{ >> +unsigned int flags = FOLL_FORCE | FOLL_WRITE; >> +

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Song Bao Hua (Barry Song)
x-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; > linux...@kvack.org; Liguozhu (Kenneth) ; chensihang > (A) > Subject: Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > On Mon, Jan 25, 2021 at 11:35:22PM +, Song Bao Hua (Barry Song) wrote: > > > >

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Jason Gunthorpe
On Mon, Jan 25, 2021 at 11:35:22PM +, Song Bao Hua (Barry Song) wrote: > > On Mon, Jan 25, 2021 at 10:21:14PM +, Song Bao Hua (Barry Song) wrote: > > > mlock, while certainly be able to prevent swapping out, it won't > > > be able to stop page moving due to: > > > * memory compaction in

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Jason Gunthorpe
On Mon, Jan 25, 2021 at 10:21:14PM +, Song Bao Hua (Barry Song) wrote: > mlock, while certainly be able to prevent swapping out, it won't > be able to stop page moving due to: > * memory compaction in alloc_pages() > * making huge pages > * numa balance > * memory compaction in CMA Enabling

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Song Bao Hua (Barry Song)
o > ; linux-accelerat...@lists.ozlabs.org; > linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; > linux...@kvack.org; Liguozhu (Kenneth) ; chensihang > (A) > Subject: Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > On Mon, Jan 25, 2021 at 10:21:1

RE: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Song Bao Hua (Barry Song)
; > iommu@lists.linux-foundation.org; linux...@kvack.org; Song Bao Hua (Barry > Song) > ; Liguozhu (Kenneth) ; > chensihang (A) > Subject: Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device > > On Mon, Jan 25, 2021 at 04:34:56PM +0800, Zhou Wang wrote: > > > +static

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Jason Gunthorpe
On Mon, Jan 25, 2021 at 04:34:56PM +0800, Zhou Wang wrote: > +static int uacce_pin_page(struct uacce_pin_container *priv, > + struct uacce_pin_address *addr) > +{ > + unsigned int flags = FOLL_FORCE | FOLL_WRITE; > + unsigned long first, last, nr_pages; > +

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Zhou Wang
On 2021/1/25 17:28, Greg Kroah-Hartman wrote: > On Mon, Jan 25, 2021 at 04:34:56PM +0800, Zhou Wang wrote: >> +static int uacce_pin_page(struct uacce_pin_container *priv, >> + struct uacce_pin_address *addr) >> +{ >> +unsigned int flags = FOLL_FORCE | FOLL_WRITE; >> +

Re: [RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Greg Kroah-Hartman
On Mon, Jan 25, 2021 at 04:34:56PM +0800, Zhou Wang wrote: > +static int uacce_pin_page(struct uacce_pin_container *priv, > + struct uacce_pin_address *addr) > +{ > + unsigned int flags = FOLL_FORCE | FOLL_WRITE; > + unsigned long first, last, nr_pages; > + struct

[RFC PATCH v2] uacce: Add uacce_ctrl misc device

2021-01-25 Thread Zhou Wang
Uacce driver supports to use devices in user space safely by SVA. However, IO page fault may happen when doing DMA operations, which will affect DMA performance severely. For some accelerators which need stable performance, it is better to avoid IO page fault totally. Current memory related APIs,