From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.atof.net (smtp1.atof.net [52.86.233.228]) by sourceware.org (Postfix) with ESMTPS id EBEA03858D37 for ; Thu, 20 Apr 2023 07:14:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org EBEA03858D37 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gluelogic.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gluelogic.com X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-Spam-Language: en X-Spam-Relay-Country: X-Spam-DCC: B=MGTINTERNET; R=smtp1.atof.net 1170; Body=1 Fuz1=1 Fuz2=1 X-Spam-RBL: X-Spam-PYZOR: Reported 0 times. Date: Thu, 20 Apr 2023 03:14:50 -0400 From: gs-cygwin.com@gluelogic.com To: Bruno Haible Cc: cygwin@cygwin.com Subject: Re: posix_spawn facility Message-ID: References: <1752276.7aRn1RRit1@nimes> <5022555.upeRZZJTqa@nimes> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5022555.upeRZZJTqa@nimes> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,KAM_DMARC_STATUS,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 List-Id: 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 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