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: Wed, 08 Oct 2014 08:29:59 -0500 Message-ID: <85ppe2vgdk.fsf@stephe-leake.org> References: <85wq8ge3gr.fsf@stephe-leake.org> <85d2a8dzkh.fsf@stephe-leake.org> <83lhowgrr3.fsf@gnu.org> <854mviej2x.fsf@stephe-leake.org> <8338b2oa0j.fsf@gnu.org> <85r3ymcr0u.fsf@stephe-leake.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1412775089 13947 80.91.229.3 (8 Oct 2014 13:31:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 8 Oct 2014 13:31:29 +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 Wed Oct 08 15:31:22 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 1XbrKr-0005k1-LX for geb-bug-gnu-emacs@m.gmane.org; Wed, 08 Oct 2014 15:31:21 +0200 Original-Received: from localhost ([::1]:36267 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XbrKr-0001fQ-42 for geb-bug-gnu-emacs@m.gmane.org; Wed, 08 Oct 2014 09:31:21 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:58129) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XbrKi-0001en-CF for bug-gnu-emacs@gnu.org; Wed, 08 Oct 2014 09:31:18 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XbrKa-0007Uu-9a for bug-gnu-emacs@gnu.org; Wed, 08 Oct 2014 09:31:12 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:45990) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XbrKa-0007Ub-6v for bug-gnu-emacs@gnu.org; Wed, 08 Oct 2014 09:31:04 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XbrKZ-0007Q9-3O for bug-gnu-emacs@gnu.org; Wed, 08 Oct 2014 09:31:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stephen Leake Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 08 Oct 2014 13:31:02 +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=B18626.141277502828481 (code B ref 18626); Wed, 08 Oct 2014 13:31:02 +0000 Original-Received: (at 18626) by debbugs.gnu.org; 8 Oct 2014 13:30:28 +0000 Original-Received: from localhost ([127.0.0.1]:37554 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XbrJl-0007Oy-LZ for submit@debbugs.gnu.org; Wed, 08 Oct 2014 09:30:27 -0400 Original-Received: from dnvrco-outbound-snat.email.rr.com ([107.14.73.225]:51312 helo=dnvrco-oedge-vip.email.rr.com) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XbrJb-0007OP-NK for 18626@debbugs.gnu.org; Wed, 08 Oct 2014 09:30:06 -0400 Original-Received: from [70.94.38.149] ([70.94.38.149:50132] helo=TAKVER) by dnvrco-oedge02 (envelope-from ) (ecelerity 3.5.0.35861 r(Momo-dev:tip)) with ESMTP id CB/96-18752-95C35345; Wed, 08 Oct 2014 13:30:01 +0000 In-Reply-To: <85r3ymcr0u.fsf@stephe-leake.org> (Stephen Leake's message of "Sun, 05 Oct 2014 13:25:53 -0500") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (windows-nt) X-RR-Connecting-IP: 107.14.64.130:25 X-Authority-Analysis: v=2.1 cv=G9mSErU5 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=Sg0YA1n-PdpcZRv8HlEA:9 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:94293 Stephen Leake writes: > It is still a problem on Windows; 12 seconds to read a megabyte is > unacceptably slow for my real application. The cause for this is the Sleep in _sys_read_ahead in w32.c. This is called from reader_thread after the wait for a single char read succeeds. The default wait is 50 ms, set by the elisp variable w32-pipe-read-delay. Setting that to 0 gives: (pipe-torture-read "/Projects/emacs/emacs-24.3.94/src/xdisp.c") 0.180000, 0.095000 only a factor of 2 slower than command-line cat. w32-pipe-read-delay is a global variable. The comment in _sys_read_ahead says there are problems with subprocess interaction when setting this to 0 on some systems. If that is still true, we may need to change this to a per-subprocess setting. In my real application, let-binding w32-pipe-read-delay for a short time is possible, and a reasonable workaround. -- -- Stephe