Top all-time · #6364
Ponyhof
Personal blog · dvdhrm.wordpress.comsystemsprogramming
Ponyhof is a personal blog at dvdhrm.wordpress.com about systems and programming. Since 2013, 13 different Hacker News readers have linked it 17 times, most often “Memfd_create(2): get file-descriptor for anonymous memory without tmpfs mount”. The last post was in 2015, but the archive is still widely read.
Too few sampled comments (8) to say how often HN recommends it.?
Why HN links it
HN readers link David Herrmann's blog for write-ups on Linux internals: systemd-logind session management, VT switching, memfd, and the KMSCON terminal emulator. Most comments cite posts as sources rather than judging them.
Summarised by Claude from a sample of 8 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Dysfunctional Programming
Most-linked posts?
- Memfd_create(2): get file-descriptor for anonymous memory without tmpfs mount3 people · 3 mentions · first linked 2014-08-15
- Session-Management on Linux2 people · 2 mentions · first linked 2013-08-25
- /2014/06/10/memfd_create2/2 people · 2 mentions · first linked 2016-12-28
- From AF_Unix to kdbus2 people · 2 mentions · first linked 2015-06-21
What Hacker News says?
No need for /dev/zero: Linux has memfd[1] and OSX has vm_remap[2]. You only need one file descriptor per heap because Linux lets you poke holes with fallocate[3]. I'll define objects with a header that looks roughly like this: struct header { off_t phys; size_t len; int localrefs; short flags; char mstrategy, type; }; phys is the offset in the heap file descriptor. len is the number of units and type is indexed into…
Comment linking /2014/06/10/memfd_create2/
on “Finger Trees: A Simple General-Purpose Data Structure (2006)”Submitted From AF_Unix to kdbus as a story · 13 points
HN discussionPlease read these posts by David Herrmann to get an idea of the improvements in reliability that systemd-logind provides to desktops: http://dvdhrm.wordpress.com/2013/08/24/session-management-on... http://dvdhrm.wordpress.com/2013/08/24/how-vt-switching-work... http://dvdhrm.wordpress.com/2013/08/25/sane-session-switchin...
Comment linking /2013/08/25/sane-session-switching/
on “Shall we fork Debian?”Submitted Memfd_create(2): get file-descriptor for anonymous memory without tmpfs mount as a story · 2 points
HN discussionThis is indeed annoying; fortunately David Herrmann is working on a new user-space terminal emulator for Linux called KMSCON which uses the same keyboard input code as XOrg (libxkbcommon) so there is hope for improvement. https://dvdhrm.wordpress.com/2012/12/10/kmscon-introduction/
Comment linking /2012/12/10/kmscon-introduction/
on “Why I dislike systemd”Submitted Open source Miracast implementation as a story · 2 points
HN discussion> This smells like they are using shared memory, which is almost certainly a security nightmare. Yes, we are using shared memory, and I agree that shared memory is a challenge but there are some mechanisms that can make it secure. The main problem with shared memory is, that one process can corrupt the data structure while another process is consuming it. Even verifying the contents of the data structure is insuffic…
Comment linking /2014/06/10/memfd_create2/
on “Show HN: Iceoryx2 – Fast IPC Library for Rust, C++, and C”Submitted Session-Management on Linux as a story · 2 points
HN discussionhttps://www.digitalocean.com/community/tutorials/systemd-ess... for the bare minimum http://linoxide.com/linux-how-to/systemd-boot-process/ for how it starts up https://lwn.net/Articles/604609/ cgroups https://lwn.net/Articles/531114/ namespaces https://dvdhrm.wordpress.com/2013/07/08/thoughts-on-linux-sy... logind/sessions/seats http://0pointer.net/blog/projects/socket-activated-container... and finally "the series…
Comment linking /2013/07/08/thoughts-on-linux-system-compositors/
on “Sad news today: systemd-resolved to be deployed in Ubuntu 16.10”Submitted Session-Management on Linux as a story · 2 points
HN discussion> memfd_create is also one of those wat kind of system calls, which initially don't appear to enable any use case that couldn't be accomplished by other means The author agrees with that. It's just a bit simpler. See e.g. https://dvdhrm.wordpress.com/tag/memfd/ The benefits of the system call according to above link are: 1) memfd_create does not require a local mount-point 2) There are no name-clashes and no global…
Comment linking /tag/memfd/
on “Keeping secrets in memfd areas”Submitted From AF_Unix to kdbus as a story · 1 points
HN discussionThe hope is to eventually remove the in-kernel terminal emulator. See here https://dvdhrm.wordpress.com/2012/08/12/killing-off-config_v...
Comment linking /2012/08/12/killing-off-config_vt/
on “Safe Terminal Escape Codes”Submitted How VT-Switching Works as a story · 1 points
HN discussionBlog post on memfd https://dvdhrm.wordpress.com/tag/memfd/
Comment linking /tag/memfd/
on “Memfd_create() syscall merged into Linux tree”
