Messages in this thread | | | From | Andy Lutomirski <> | Date | Wed, 15 Apr 2015 15:28:58 -0700 | Subject | Re: [GIT PULL] kdbus for 4.1-rc1 |
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On Wed, Apr 15, 2015 at 3:18 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > On Wed, Apr 15, 2015 at 03:11:17PM -0700, Andy Lutomirski wrote: > >> This is functionally identical to passing AF_UNIX socket fds over >> SCM_RIGHTS, but I want something much lighter weight. > > Most of the weight in SCM_RIGHTS comes from the fact that you can > pass AF_UNIX sockets over it, which requires a garbage collector. > Exclude that and suddenly it becomes very cheap...
I should have been more specific. I don't mean the performance of SCM_RIGHTS itself; I mean the memory overhead of keeping tons of fds around, each with their socket data structures and buffers.
I think that dbus could be quite efficiently implemented with a userspace daemon that just introduces peers to each other, but the fd explosion could be rather bad for some use cases.
I'll be the first to admit that I don't have a clean API in mind. There was a lightweight fd proposal way back when, but it never went anywhere, and it might not be suitable anyway.
--Andy
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