From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95241C7619A for ; Sat, 8 Apr 2023 20:01:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229521AbjDHUBs (ORCPT ); Sat, 8 Apr 2023 16:01:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjDHUBs (ORCPT ); Sat, 8 Apr 2023 16:01:48 -0400 Received: from eggs.gnu.org (eggs.gnu.org [IPv6:2001:470:142:3::10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E572E6184 for ; Sat, 8 Apr 2023 13:01:46 -0700 (PDT) Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1plEkn-0003Tb-Dp; Sat, 08 Apr 2023 16:01:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=Yvt38icGOBHd41IKUhY2yJZrQODpIrKxSmFka0PVe6g=; b=XLZ7JOBEDTcd y+szYRoLiVlAUfcKhsvgOEwiTvDjoVEpT9vDpl2232F1sImz9D4JEuzM66giS6x9xV7Cvu/AtuTJk vRvGi4/sbrIu4r0K7R93YtE0R8mb6sUaYQUXyoH2udd8zkWIjcSu4y6nTFnsUCm2ZVpSJExmhAAP/ nNeeI3g3Sq/wgK7rbw+jjVmaT3qBaDJLQz9VyIOhQHHWxkOA99aTyVIC7mUDM8wIcdI8N8qJPwjUS ZCrnTbuRjXER/yNEoWSUwAD0aHyt7CQDsUrt4lt9/jTvyelTnuXNvibHU1zgxwA5ZELEfIqFrimEg 5IUNm7lGtIRkHVkay1PLWw==; Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1plEki-000353-Ig; Sat, 08 Apr 2023 16:01:40 -0400 Date: Sat, 08 Apr 2023 23:02:11 +0300 Message-Id: <83bkjym9bw.fsf@gnu.org> From: Eli Zaretskii To: Dirk Gouders Cc: alx.manpages@gmail.com, cjwatson@debian.org, linux-man@vger.kernel.org, help-texinfo@gnu.org, nabijaczleweli@nabijaczleweli.xyz, g.branden.robinson@gmail.com, groff@gnu.org In-Reply-To: (message from Dirk Gouders on Sat, 08 Apr 2023 21:48:13 +0200) Subject: Re: Accessibility of man pages References: <073413e2-7d35-f0d7-26eb-f66908d7af6a@gmail.com> <834jpuuc1a.fsf@gnu.org> <6ea6d1fe-375f-487a-b524-adc86880d3de@gmail.com> <83sfddqvk3.fsf@gnu.org> <390c8bba-6089-b006-eaf1-9fcfda2c6c4b@gmail.com> <837cumonv9.fsf@gnu.org> <78ca213f-8723-dccb-e131-081400c28e5d@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org > From: Dirk Gouders > Cc: Colin Watson , Eli Zaretskii , > linux-man@vger.kernel.org, help-texinfo@gnu.org, > nabijaczleweli@nabijaczleweli.xyz, g.branden.robinson@gmail.com, > groff@gnu.org > Date: Sat, 08 Apr 2023 21:48:13 +0200 > > $ find /usr/share/man -type f -exec bzgrep -l RLIMIT_NOFILE {} \; > /usr/share/man/man1/runuser.1.bz2 > /usr/share/man/man1/su.1.bz2 > /usr/share/man/man1/nghttpx.1.bz2 > /usr/share/man/man3/getdtablesize.3.bz2 > /usr/share/man/man3/mq_open.3.bz2 > /usr/share/man/man3/errno.3.bz2 > /usr/share/man/man3/sysconf.3.bz2 > /usr/share/man/man3p/getrlimit.3p.bz2 > /usr/share/man/man3p/sysconf.3p.bz2 > /usr/share/man/man3p/posix_spawn_file_actions_addclose.3p.bz2 > /usr/share/man/man0p/sys_resource.h.0p.bz2 > /usr/share/man/man2/pidfd_open.2.bz2 > /usr/share/man/man2/poll.2.bz2 > /usr/share/man/man2/getrlimit.2.bz2 > /usr/share/man/man2/open.2.bz2 > /usr/share/man/man2/select.2.bz2 > /usr/share/man/man2/fcntl.2.bz2 > /usr/share/man/man2/seccomp_unotify.2.bz2 > /usr/share/man/man2/dup.2.bz2 > /usr/share/man/man2/pidfd_getfd.2.bz2 > /usr/share/man/man7/fanotify.7.bz2 > /usr/share/man/man7/capabilities.7.bz2 > /usr/share/man/man7/unix.7.bz2 > /usr/share/man/man5/proc.5.bz2 > > Yes, it's very slow but close to `man -K`: > > find... man -K... > > real 107.45 real 96.34 > user 117.06 user 70.11 > sys 14.43 sys 26.86 > > [a thought later] > > Oh, I found something much faster: > > $ time -p find /usr/share/man -type f | xargs bzgrep -l RLIMIT_NOFILE > [snip] > > real 24.30 > user 32.34 > sys 6.84 > > Hmm, perhaps, someone has an explanation for this? Multiprocessing, obviously. Your CPU has more than one execution unit, so the pipe via xargs runs 'find' and 'bzgrep' in parallel on two different execution units. By contrast, "find -exec" runs them sequentially, in a single thread.