From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eric Abrahamsen Newsgroups: gmane.emacs.bugs Subject: bug#50877: 28.0.50; Gnus: nnimap backend is extremely slow to initialise new groups Date: Tue, 28 Sep 2021 21:25:37 -0700 Message-ID: <8735ponh32.fsf@ericabrahamsen.net> References: <87ee98pf11.fsf@precedence.co.uk> <87bl4c4c6q.fsf@ericabrahamsen.net> <87pmssqsd2.fsf@precedence.co.uk> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="32657"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 50877@debbugs.gnu.org, Lars Ingebrigtsen , Stefan Kangas To: Morgan Willcock Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Sep 29 06:26:15 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mVRAd-0008FH-6i for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 29 Sep 2021 06:26:15 +0200 Original-Received: from localhost ([::1]:42286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mVRAc-0006GV-1q for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 29 Sep 2021 00:26:14 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:43208) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mVRAQ-0006G7-2F for bug-gnu-emacs@gnu.org; Wed, 29 Sep 2021 00:26:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:35926) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mVRAP-000221-Qs for bug-gnu-emacs@gnu.org; Wed, 29 Sep 2021 00:26:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1mVRAP-0002ai-LR for bug-gnu-emacs@gnu.org; Wed, 29 Sep 2021 00:26:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eric Abrahamsen Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Wed, 29 Sep 2021 04:26:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 50877 X-GNU-PR-Package: emacs Original-Received: via spool by 50877-submit@debbugs.gnu.org id=B50877.16328895479935 (code B ref 50877); Wed, 29 Sep 2021 04:26:01 +0000 Original-Received: (at 50877) by debbugs.gnu.org; 29 Sep 2021 04:25:47 +0000 Original-Received: from localhost ([127.0.0.1]:47472 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mVRAB-0002aB-1E for submit@debbugs.gnu.org; Wed, 29 Sep 2021 00:25:47 -0400 Original-Received: from mail.ericabrahamsen.net ([52.70.2.18]:42816) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1mVRA9-0002Zw-7q for 50877@debbugs.gnu.org; Wed, 29 Sep 2021 00:25:45 -0400 Original-Received: from localhost (c-71-197-232-156.hsd1.wa.comcast.net [71.197.232.156]) (Authenticated sender: eric@ericabrahamsen.net) by mail.ericabrahamsen.net (Postfix) with ESMTPSA id D87CBFA09E; Wed, 29 Sep 2021 04:25:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ericabrahamsen.net; s=mail; t=1632889539; bh=yq72EujzHzHun2GXlQadwevcPNzkfIDfi6wCJYzn0uY=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=bMC1a9XFpIf0M75t4tGXqKDYJVHMGvuyynqraFrSRsoVWMvwsDcMRe0mMAR8IpZG8 fCsSLNcIElkYkK+dL2F79U8hQOPPMS5+1oJvgRGaY8T2mrwBPtzuTX43a76yYX5sQT MfFRCp/lV+HOSnIIhPCajvyjl881DR7vHGvj4xAY= In-Reply-To: <87pmssqsd2.fsf@precedence.co.uk> (Morgan Willcock's message of "Tue, 28 Sep 2021 22:53:45 +0100") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:215812 Archived-At: Morgan Willcock writes: > Eric Abrahamsen writes: > >> You could try reverting 20f7fa691b7c2859b96550d9ccb326bf394e160d and see >> if that fixes it. That change went in in April, though, so unless you >> haven't updated for a while (or you've been seeing this problem for a >> long time) it might not be likely. > > Reverting that commit fixes it for me. I'm cc'ing Lars and Stefan Kangas, who are the most "involved" here. The benchmarks are gruesome: (defun old-gnus-set-difference (list1 list2) "Return a list of elements of LIST1 that do not appear in LIST2." (let ((hash2 (make-hash-table :test 'eq)) (result nil)) (dolist (elt list2) (puthash elt t hash2)) (dolist (elt list1) (unless (gethash elt hash2) (setq result (cons elt result)))) (nreverse result))) (let* ((common1 (number-sequence 0 200)) (common2 (number-sequence 501 700)) (l1 (append common1 (number-sequence 200 500 2) common2)) (l2 (append common1 (number-sequence 201 500 2) common2)) (results (list (benchmark-run 1000 (old-gnus-set-difference l1 l2)) (benchmark-run 1000 (seq-difference l1 l2 #'eq))))) results)-> ((1.842791826 7 1.4057783080000021) (14.284496493999999 4 0.7823414249999985)) This is a particularly bad example -- when there was no common2 `seq-difference' performed better, but I think it still around 6 seconds to the old function's 2. Probably still worth a dedicated function for Gnus? (Or a rewrite of `seq-difference'...) Eric