Re: [PATCH v5 0/4] vm: add a syscall to map a process memory into a pipe

From: Pavel Emelyanov
Date: Mon Feb 26 2018 - 04:02:49 EST


On 02/21/2018 03:44 AM, Andrew Morton wrote:
> On Tue, 9 Jan 2018 08:30:49 +0200 Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> wrote:
>
>> This patches introduces new process_vmsplice system call that combines
>> functionality of process_vm_read and vmsplice.
>
> All seems fairly strightforward. The big question is: do we know that
> people will actually use this, and get sufficient value from it to
> justify its addition?

Yes, that's what bothers us a lot too :) I've tried to start with finding out if anyone
used the sys_read/write_process_vm() calls, but failed :( Does anybody know how popular
these syscalls are? If its users operate on big amount of memory, they could benefit from
the proposed splice extension.

-- Pavel