From: gs-cygwin.com@gluelogic.com
To: Bruno Haible <bruno@clisp.org>
Cc: cygwin@cygwin.com
Subject: Re: posix_spawn facility
Date: Thu, 20 Apr 2023 03:14:50 -0400 [thread overview]
Message-ID: <ZEDmai2kO+dfxWut@xps13> (raw)
In-Reply-To: <5022555.upeRZZJTqa@nimes>
On Mon, Apr 17, 2023 at 08:44:51PM +0200, Bruno Haible via Cygwin wrote:
> Btw, there are two more functions in the posix_spawn family meanwhile:
> * posix_spawn_file_actions_addchdir_np
> implemented by glibc [1], musl libc, macOS, FreeBSD [2], Solaris ≥ 11.3
> used by a few packages (Firefox, Chromium, Rust)
> * posix_spawn_file_actions_addfchdir_np
> implemented in glibc, musl libc
> but not used by any package so far [3].
>
> The next POSIX will contain these functions (without the _np suffix).[4]
>
> Bruno
>
> [1] https://sourceware.org/bugzilla/show_bug.cgi?id=17405
> [2] https://man.freebsd.org/cgi/man.cgi?query=posix_spawn_file_actions_adddup2&apropos=0&sektion=3&manpath=FreeBSD+11-current&format=html
> [3] https://codesearch.debian.net/
> [4] https://www.austingroupbugs.net/view.php?id=1208
With regards to [3] above, the next lighttpd release (lighttpd 1.4.70)
will use posix_spawn_file_actions_addfchdir_np(), where available, for
spawning CGI programs.
I have not yet tested under cygwin, but under Linux the overhead of
initial CGI process creation can be greatly reduced by using
posix_spawn() instead of fork(),execve(). The speedup is inversely
proportional to how much work the target script performs (compared to
the overhead of initial process creation). On x86_64 Linux, running a
minimal C program for CGI can be ~60% faster in lighttpd when using
posix_spawn()! When running a minimal /bin/sh program for CGI, the
speedup is "only" ~20%! (Those numbers were obtained from running
h2load and weighttp microbenchmarks with the minimal CGI programs.)
minimal C program for CGI (compiled gcc -O3):
#include <unistd.h>
static const char resp[] = "Status: 200\n\n";
int main(void) { write(STDOUT_FILENO, resp, sizeof(resp)-1); return 0; }
minimal /bin/sh program for CGI:
#!/bin/sh
printf 'Status: 200\n\n'
Cheers, Glenn
next prev parent reply other threads:[~2023-04-20 7:14 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-16 11:46 Bruno Haible
2023-04-17 9:18 ` Corinna Vinschen
2023-04-17 18:44 ` Bruno Haible
2023-04-18 9:25 ` Corinna Vinschen
2023-04-18 20:49 ` Eric Blake
2023-04-18 21:00 ` Corinna Vinschen
2023-04-18 22:10 ` Bruno Haible
2023-04-19 2:39 ` Eric Blake
2023-04-19 8:19 ` Corinna Vinschen
2023-04-19 11:56 ` Bruno Haible
2023-04-20 6:52 ` Csaba Raduly
2023-07-31 18:58 ` Eric Blake
2023-07-31 19:12 ` Corinna Vinschen
2023-04-19 8:24 ` Corinna Vinschen
2023-04-19 11:24 ` posix_spawn_file_actions_add[f]chdir_np Bruno Haible
2023-04-19 15:05 ` posix_spawn_file_actions_add[f]chdir_np Corinna Vinschen
2023-04-19 19:13 ` posix_spawn_file_actions_add[f]chdir_np Corinna Vinschen
2023-04-19 21:33 ` posix_spawn_file_actions_add[f]chdir_np Eliot Moss
2023-04-20 10:27 ` posix_spawn_file_actions_add[f]chdir_np Bruno Haible
2023-04-19 10:48 ` posix_spawn facility Bruno Haible
2023-04-20 7:14 ` gs-cygwin.com [this message]
2023-04-20 8:35 ` Corinna Vinschen
2023-04-20 10:18 ` Bruno Haible
2023-04-20 14:21 ` Corinna Vinschen
2023-04-20 14:40 ` Corinna Vinschen
2023-04-20 14:58 ` Bruno Haible
2023-04-20 15:40 ` Corinna Vinschen
2023-04-20 18:46 ` gs-cygwin.com
2023-04-20 18:40 ` gs-cygwin.com
2023-04-20 19:31 ` Bruno Haible
2023-04-20 20:00 ` gs-cygwin.com
2023-05-10 9:15 ` gs-cygwin.com
2023-04-20 18:04 ` gs-cygwin.com
2023-05-10 8:59 ` gs-cygwin.com
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