digitalmars.D - fork vs. posix_spawn (vfork)
- notna (9/9) Oct 14 2018 Hi D gurus.
- Petar Kirov [ZombineDev] (27/37) Oct 14 2018 Hi notna,
- Petar Kirov [ZombineDev] (15/17) Oct 15 2018 Here's the full deal:
- Steven Schveighoffer (4/18) Oct 15 2018 Related:
Hi D gurus. Did read an interesting post form GitLab [1] how they improved performance by 30x by just going to go_v1.9... because they again went from "fork" to "posix_spawn"... I've searched the GitHub DLANG org for "posix_spawn" and didn't find a hit... so asking myself and you.... is DLANG still on "fork" and could there be some performance improvement potential? [1] https://about.gitlab.com/2018/01/23/how-a-fix-in-go-19-sped-up-our-gitaly-service-by-30x/
Oct 14 2018
On Sunday, 14 October 2018 at 11:36:28 UTC, notna wrote:Hi D gurus. Did read an interesting post form GitLab [1] how they improved performance by 30x by just going to go_v1.9... because they again went from "fork" to "posix_spawn"... [1] https://about.gitlab.com/2018/01/23/how-a-fix-in-go-19-sped-up-our-gitaly-service-by-30x/Hi notna, Thanks for the interesting article.I've searched the GitHub DLANG org for "posix_spawn" and didn't find a hit...Indeed currently (as of DMD 2.082.1) druntime does not include bindings of posix_spawn [1]. The nice thing about D is that if you need to use a C function that's not yet declared in druntime it's very easy to add the declaration to your app and use it. I looked at glibc's implementation and translated the declarations. You can find them along with the example from the man page here: https://run.dlang.io/gist/ZombineDev/536eb8b456cc365b7ee05133ec452627?compiler=dmd (if you want to use posix_spawn in your app/library copy the code from line 133 till the end of the file).so asking myself and you.... is DLANG still on "fork" and could there be some performance improvement potential?One cannot say whether D is "on fork" or not because unlike Go, everyone is free to use whatever system function they need, without explicit cooperation from upstream. Though probably many apps or libraries use the high-level functions declared in https://dlang.org/phobos/std_process instead of using the low-level system functions directly. In particular, spawnProcess [2] is currently implemented via fork/exec. I found an open issue about optimizing std.process: https://issues.dlang.org/show_bug.cgi?id=14770. I'll look into making a pull request to druntime about posix_spawn, though no promises for phobos, as there the code is a bit more involved and would need more careful analysis. [1]: http://man7.org/linux/man-pages/man3/posix_spawn.3.html [2]: https://dlang.org/phobos/std_process#.spawnProcess
Oct 14 2018
Petar Kirov [ZombineDev] <petar.p.kirov gmail.com> On Sunday, 14 October 2018 at 17:33:37 UTC, Petar Kirov [ZombineDev] wrote:I'll look into making a pull request to druntime about posix_spawn [..]Here's the full deal: https://github.com/dlang/druntime/pull/2329/files with support for: Linux Glibc Linux Bionic libc Linux Musl libc Linux uClibc Darwin (macOS and iOS) FreeBSD NetBSD OpenBSD DragonFlyBSD Solaris/Illumos (thanks n8sh!)
Oct 15 2018
On 10/14/18 7:36 AM, notna wrote:Hi D gurus. Did read an interesting post form GitLab [1] how they improved performance by 30x by just going to go_v1.9... because they again went from "fork" to "posix_spawn"... I've searched the GitHub DLANG org for "posix_spawn" and didn't find a hit... so asking myself and you.... is DLANG still on "fork" and could there be some performance improvement potential? [1] https://about.gitlab.com/2018/01/23/how-a-fix-in-go-19-sped-up-our-gi aly-service-by-30x/Related: https://issues.dlang.org/show_bug.cgi?id=14770 -Steve
Oct 15 2018