Re: [PATCH1/2] Use spawn() on Cygwin
Date: Fri, 2 Aug 2013 22:49:31 -0400 From: Christopher Faylor m...@cgf.cx On Tue, Jul 30, 2013 at 08:02:54PM +0300, Eli Zaretskii wrote: Date: Tue, 30 Jul 2013 11:52:58 -0500 From: Norbert Thiebaud nthieb...@gmail.com Cc: Pavel Fedin p.fe...@samsung.com, bug-make@gnu.org fork() is a very expensive operation in cygwin. Yes, I know. But without it, some things that are expected of a Posix behavior will not work. A notable example is that the child process initially has all the file descriptors and global variables that the parent had. 'spawn' does not necessarily guarantee that. Thank you Eli. This is my reservation about this change too. I maintain the make package for Cygwin and if I have reservations, you can be sure that it won't make it into the released version. And, btw, I think there's a thread on the Cygwin list just now about one such problem. ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
On Sat, Aug 03, 2013 at 11:16:44AM +0300, Eli Zaretskii wrote: Date: Fri, 2 Aug 2013 22:49:31 -0400 From: Christopher Faylor m...@cgf.cx On Tue, Jul 30, 2013 at 08:02:54PM +0300, Eli Zaretskii wrote: Date: Tue, 30 Jul 2013 11:52:58 -0500 From: Norbert Thiebaud nthieb...@gmail.com Cc: Pavel Fedin p.fe...@samsung.com, bug-make@gnu.org fork() is a very expensive operation in cygwin. Yes, I know. But without it, some things that are expected of a Posix behavior will not work. A notable example is that the child process initially has all the file descriptors and global variables that the parent had. 'spawn' does not necessarily guarantee that. Thank you Eli. This is my reservation about this change too. I maintain the make package for Cygwin and if I have reservations, you can be sure that it won't make it into the released version. And, btw, I think there's a thread on the Cygwin list just now about one such problem. Yep. cgf ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
[PATCH1/2] Use spawn() on Cygwin
Hello! Please take this patch, Cygwin team told that they would like to integrate with upstream. I have already posted it some time ago but got no reply. The patch significantly improves performance of Make under Cygwin. Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia make-3.82.90-1-use-spawn-on-cygwin.diff Description: Binary data ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
From: Pavel Fedin p.fe...@samsung.com Date: Tue, 30 Jul 2013 14:42:23 +0400 Please take this patch, Cygwin team told that they would like to integrate with upstream. I have already posted it some time ago but got no reply. The patch significantly improves performance of Make under Cygwin. Thanks. Is there any discussion we could read about that with the details of the problem and how/why does the proposed patch solves it? In general, I feel it's wrong to do this: Cygwin is a Posix platform, so it should be using the Posix code, to be as compatible with other Posix platforms as possible. EMX is not a Posix platform, so using its code will likely make the Cygwin Make deviate from Posix behavior at times. ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
Hi... bug-make-bounces+roland.schwingel=onevision@gnu.org wrote on 30.07.2013 17:39:10: From: Pavel Fedin p.fe...@samsung.com Date: Tue, 30 Jul 2013 14:42:23 +0400 Please take this patch, Cygwin team told that they would like to integrate with upstream. I have already posted it some time ago but got no reply. The patch significantly improves performance of Make under Cygwin. Thanks. Is there any discussion we could read about that with the details of the problem and how/why does the proposed patch solves it? In general, I feel it's wrong to do this: Cygwin is a Posix platform, so it should be using the Posix code, to be as compatible with other Posix platforms as possible. EMX is not a Posix platform, so using its code will likely make the Cygwin Make deviate from Posix behavior at times. I am using Pavels patch for some months now in my private version of gnumake on cygwin heavily and I could not find any regression with it up to now and gnumake is in my use cases clearly faster. It is still not a stallion badged red italian car, but it is cruising its curves noticably snappier on cygwin now. Using EMX is a shortcut to achieve the usage of spawn() over fork(). It might not be the cleanest choice but it works. Maybe Pavel finds the time to make the patch distinct to cygwin itself. Just my $0.02, Roland___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
On Tue, 2013-07-30 at 18:39 +0300, Eli Zaretskii wrote: In general, I feel it's wrong to do this: Cygwin is a Posix platform, so it should be using the Posix code, to be as compatible with other Posix platforms as possible. EMX is not a Posix platform, so using its code will likely make the Cygwin Make deviate from Posix behavior at times. If we decide to take this change I think we should reduce it to a single #define, such as HAVE_W32_SPAWN or similar, as we did with the HAVE_DOS_PATHS, set it in one place based on __EMX__ etc., then use that single macro where we want to check for spawn() in the code. ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
Hi Eli... Eli Zaretskii e...@gnu.org wrote on 30.07.2013 18:29:53: From: Eli Zaretskii e...@gnu.org To: Roland Schwingel roland.schwin...@onevision.com Cc: bug-make@gnu.org, p.fe...@samsung.com Date: 30.07.2013 18:32 Subject: Re: [PATCH1/2] Use spawn() on Cygwin Cc: bug-make@gnu.org, Pavel Fedin p.fe...@samsung.com From: Roland Schwingel roland.schwin...@onevision.com Date: Tue, 30 Jul 2013 18:12:55 +0200 I am using Pavels patch for some months now in my private version of gnumake on cygwin heavily and I could not find any regression with it up to now and gnumake is in my use cases clearly faster. Thanks for the info. What version of Make are you using? If it is not the version from the git repo, please try that, and in particular the new --output-sync feature. My version is from git, but already some months old (I checked it out on 20130114). So it is not fresh bananas. Currently I am enjailed by a very tight schedule. Maybe I can update my version of gnumake beginning of next week. Sorry, Roland ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
On Tue, Jul 30, 2013 at 10:39 AM, Eli Zaretskii e...@gnu.org wrote: From: Pavel Fedin p.fe...@samsung.com Date: Tue, 30 Jul 2013 14:42:23 +0400 Please take this patch, Cygwin team told that they would like to integrate with upstream. I have already posted it some time ago but got no reply. The patch significantly improves performance of Make under Cygwin. Thanks. Is there any discussion we could read about that with the details of the problem and how/why does the proposed patch solves it? fork() is a very expensive operation in cygwin. we are seeing that in LibreOffice build a lot. I will try to pick up that patch and report numbers on it (we have a pretty big make, with 125K+ targets http://skyfromme.wordpress.com/2013/02/28/one/ ) In general, I feel it's wrong to do this: Cygwin is a Posix platform, so it should be using the Posix code, to be as compatible with other Posix platforms as possible. EMX is not a Posix platform, so using its code will likely make the Cygwin Make deviate from Posix behavior at times. in theory you are right... in practice Cygwin maybe be posix, but it's underlying OS is not and the emulation layer can be very costly. Norbert ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
Date: Tue, 30 Jul 2013 11:52:58 -0500 From: Norbert Thiebaud nthieb...@gmail.com Cc: Pavel Fedin p.fe...@samsung.com, bug-make@gnu.org fork() is a very expensive operation in cygwin. Yes, I know. But without it, some things that are expected of a Posix behavior will not work. A notable example is that the child process initially has all the file descriptors and global variables that the parent had. 'spawn' does not necessarily guarantee that. ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
Re: [PATCH1/2] Use spawn() on Cygwin
Date: Wed, 31 Jul 2013 01:24:45 +0400 From: Pavel Fedin pavel_fe...@mail.ru Cc: bug-make@gnu.org There was a short discussion in Cygwin ML with test results, sorry, i cannot find the URL, Google fails to find it. Can you at least tell when (year and month) this discussion took place? In any case, I think such a change can only be accepted as an optional feature, preferably controlled by a command-line option. I think it's wrong to use this by default, certainly not to let users a fire escape in case this causes differences in behavior in some use cases. ___ Bug-make mailing list Bug-make@gnu.org https://lists.gnu.org/mailman/listinfo/bug-make
