Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Andy Lutomirski
On Tue, Mar 14, 2017 at 9:12 AM, Till Smejkal wrote: > On Mon, 13 Mar 2017, Andy Lutomirski wrote: >> On Mon, Mar 13, 2017 at 7:07 PM, Till Smejkal >> wrote: >> > On Mon, 13 Mar 2017, Andy Lutomirski wrote: >> >> This sounds rather

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Luck, Tony
On Wed, Mar 15, 2017 at 03:02:34PM -0700, Till Smejkal wrote: > I don't agree here. VAS segments are basically in-memory files that are > handled by > the kernel directly without using a file system. Hence, if an application > uses a VAS > segment to store data the same rules apply as if it uses

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Matthew Wilcox
On Wed, Mar 15, 2017 at 09:51:31AM -0700, Andy Lutomirski wrote: > > VAS segments on the other side allow sharing of pure in memory data by > > arbitrary related tasks without the need of a file. This becomes especially > > interesting if one combines VAS segments with non-volatile memory since

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Rich Felker
On Wed, Mar 15, 2017 at 12:44:47PM -0700, Till Smejkal wrote: > On Wed, 15 Mar 2017, Andy Lutomirski wrote: > > > One advantage of VAS segments is that they can be globally queried by > > > user programs > > > which means that VAS segments can be shared by applications that not > > > necessarily

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Till Smejkal
On Wed, 15 Mar 2017, Andy Lutomirski wrote: > > One advantage of VAS segments is that they can be globally queried by user > > programs > > which means that VAS segments can be shared by applications that not > > necessarily have > > to be related. If I am not mistaken, MAP_SHARED of pure in

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Till Smejkal
On Wed, 15 Mar 2017, Andy Lutomirski wrote: > On Wed, Mar 15, 2017 at 12:44 PM, Till Smejkal > wrote: > > On Wed, 15 Mar 2017, Andy Lutomirski wrote: > >> > One advantage of VAS segments is that they can be globally queried by > >> > user programs > >> > which means

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Till Smejkal
On Wed, 15 Mar 2017, Luck, Tony wrote: > On Wed, Mar 15, 2017 at 03:02:34PM -0700, Till Smejkal wrote: > > I don't agree here. VAS segments are basically in-memory files that are > > handled by > > the kernel directly without using a file system. Hence, if an application > > uses a VAS > >

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Thomas Gleixner
On Wed, 15 Mar 2017, Till Smejkal wrote: > On Wed, 15 Mar 2017, Andy Lutomirski wrote: > > > VAS segments on the other side would provide a functionality to > > > achieve the same without the need of any mounted filesystem. However, > > > I agree, that this is just a small advantage compared to

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Andy Lutomirski
On Wed, Mar 15, 2017 at 12:44 PM, Till Smejkal wrote: > On Wed, 15 Mar 2017, Andy Lutomirski wrote: >> > One advantage of VAS segments is that they can be globally queried by user >> > programs >> > which means that VAS segments can be shared by applications that not

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Thomas Gleixner
On Thu, 16 Mar 2017, Till Smejkal wrote: > On Thu, 16 Mar 2017, Thomas Gleixner wrote: > > Why do we need yet another mechanism to represent something which looks > > like a file instead of simply using existing mechanisms and extend them? > > You are right. I also recognized during the

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Till Smejkal
On Thu, 16 Mar 2017, Thomas Gleixner wrote: > On Thu, 16 Mar 2017, Till Smejkal wrote: > > On Thu, 16 Mar 2017, Thomas Gleixner wrote: > > > Why do we need yet another mechanism to represent something which looks > > > like a file instead of simply using existing mechanisms and extend them? > > >

Re: [RFC PATCH 00/13] Introduce first class virtual address spaces

2017-03-16 Thread Till Smejkal
On Thu, 16 Mar 2017, Thomas Gleixner wrote: > Why do we need yet another mechanism to represent something which looks > like a file instead of simply using existing mechanisms and extend them? You are right. I also recognized during the discussion with Andy, Chris, Matthew, Luck, Rich and the