From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stephen Leake Newsgroups: gmane.emacs.bugs Subject: bug#18626: 24.3.94; communication with subprocess is slow Date: Sun, 05 Oct 2014 13:19:18 -0500 Message-ID: <85vbnycrbt.fsf@stephe-leake.org> References: <85wq8ge3gr.fsf@stephe-leake.org> <83oatsgswd.fsf@gnu.org> <858ukuejps.fsf@stephe-leake.org> <85zjdad47f.fsf@stephe-leake.org> <831tqmo9v4.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1412533225 8722 80.91.229.3 (5 Oct 2014 18:20:25 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 5 Oct 2014 18:20:25 +0000 (UTC) Cc: 18626@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sun Oct 05 20:20:17 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XaqPp-0002B2-22 for geb-bug-gnu-emacs@m.gmane.org; Sun, 05 Oct 2014 20:20:17 +0200 Original-Received: from localhost ([::1]:48302 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XaqPo-0003Ob-LC for geb-bug-gnu-emacs@m.gmane.org; Sun, 05 Oct 2014 14:20:16 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:37322) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XaqPf-0003GH-UF for bug-gnu-emacs@gnu.org; Sun, 05 Oct 2014 14:20:13 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XaqPa-00016d-KB for bug-gnu-emacs@gnu.org; Sun, 05 Oct 2014 14:20:07 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:43330) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XaqPa-00016E-Fc for bug-gnu-emacs@gnu.org; Sun, 05 Oct 2014 14:20:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XaqPZ-00046s-VP for bug-gnu-emacs@gnu.org; Sun, 05 Oct 2014 14:20:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stephen Leake Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 05 Oct 2014 18:20:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18626 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 18626-submit@debbugs.gnu.org id=B18626.141253316515746 (code B ref 18626); Sun, 05 Oct 2014 18:20:01 +0000 Original-Received: (at 18626) by debbugs.gnu.org; 5 Oct 2014 18:19:25 +0000 Original-Received: from localhost ([127.0.0.1]:34894 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XaqOy-00045u-Na for submit@debbugs.gnu.org; Sun, 05 Oct 2014 14:19:25 -0400 Original-Received: from dnvrco-outbound-snat.email.rr.com ([107.14.73.232]:31357 helo=dnvrco-oedge-vip.email.rr.com) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XaqOu-00045i-V3 for 18626@debbugs.gnu.org; Sun, 05 Oct 2014 14:19:22 -0400 Original-Received: from [70.94.38.149] ([70.94.38.149:49600] helo=TAKVER) by dnvrco-oedge03 (envelope-from ) (ecelerity 3.5.0.35861 r(Momo-dev:tip)) with ESMTP id 11/DF-27958-6AB81345; Sun, 05 Oct 2014 18:19:19 +0000 In-Reply-To: <831tqmo9v4.fsf@gnu.org> (Eli Zaretskii's message of "Sun, 05 Oct 2014 17:43:27 +0300") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (windows-nt) X-RR-Connecting-IP: 107.14.64.142:25 X-Authority-Analysis: v=2.1 cv=L8aTQoj8 c=1 sm=1 tr=0 a=AppmJ/7ZOOFWL/q6u6u93g==:117 a=AppmJ/7ZOOFWL/q6u6u93g==:17 a=ayC55rCoAAAA:8 a=9XSUBuVRJI8A:10 a=o_R75loqY_IA:10 a=9i_RQKNPAAAA:8 a=mDV3o1hIAAAA:8 a=GwgV5YMEs9_6KFwOCs8A:9 a=ii61gXl28gQA:10 a=FMD1XRJ_Ct4A:10 X-Cloudmark-Score: 0 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:94177 Archived-At: Eli Zaretskii writes: >> From: Stephen Leake >> Cc: 18626@debbugs.gnu.org >> Date: Sun, 05 Oct 2014 08:41:08 -0500 >> >> (find-file "xdisp.c") >> (pipe-torture >> "/home/Projects/org.emacs.ada-mode.stephe-1/build/wisi/debug_counted" >> "4096" "974230") >> >> 0.344027 >> >> This is comparable to the time on Windows with a large buffer in the >> subprocess. So apparently it is not using the same delay in >> send_process. Or the IO system is providing a large buffer. > > Evidently, subprocess I/O is more efficient on GNU/Linux than it is on > Windows. Perhaps this is related to the fact that by default > GNU/Linux uses PTYs for that, not pipes. Did you try your experiments > with process-connection-type bound to nil? On Debian: (setq process-connection-type nil) (pipe-torture-read "/home/Projects/emacs/emacs-24.3.94/src/xdisp.c") 0.074980 no signficant change (find-file "xdisp.c") (pipe-torture "/home/Projects/org.emacs.ada-mode.stephe-1/build/wisi/debug_counted" "4096" "974230") 0.294485, 0.304046, 0.343767 (pipe-torture "/home/Projects/org.emacs.ada-mode.stephe-1/build/wisi/debug_counted" "40000" "974230") 0.341241, 0.342165 Slower than pty, but much faster than Windows, and still independent of subprocess read buffer size. (setq process-connection-type nil) also eliminates the line-by-line read; for a buffer size of 4096, Read returns 4096 until the end of the text. For a buffer size of 40000, Read returns 40000 or 25536 until the end of the text. (+ 40000 25536) = 65536, which makes sense for the default pipe buffer size. Given a send_process delay of 0.020 on EWOULD_BLOCK, and a buffer size of 65536, the expected write time is (* 0.020 (/ 974230 65536)) = 0.28, comparable to what we see. Apparently pty's do the line by line send. Which makes sense for a "psuedo-terminal". And they also apparently use a larger internal buffer. -- -- Stephe