From owner-freebsd-bugs@freebsd.org Fri Jan 6 23:32:44 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8767DCA2FCF for ; Fri, 6 Jan 2017 23:32:44 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 773AC1CD1 for ; Fri, 6 Jan 2017 23:32:44 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v06NWinm066383 for ; Fri, 6 Jan 2017 23:32:44 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 215836] [PATCH] sbin/dmesg: support new flag for watching messages Date: Fri, 06 Jan 2017 23:32:44 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: bin X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: joe@thrallingpenguin.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Jan 2017 23:32:44 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D215836 --- Comment #4 from joe@thrallingpenguin.com --- Thank you for your feedback. I cannot simply go through syslog, as too much delay and overhead. I am proposing three solutions to this. Which sounds the most likely to suc= ceed in being accepted? 1. In researching "sys/kern/subr_log.c", I see it only accepts a single pro= cess watching (as you've kindly mentioned). Since the whole point of this file is centered around read-only operations; I feel it would be safe and fairly non-complex to support multiple processes performing open() and kevent() ca= lls by switching to a linked list of "struct selinfo". Each waiting process may then utilize kevent() mechanisms; with additional changes to the mutex call= s. 2. Use the value of "kern.log_wakeups_per_second" to calculate a better sle= ep() call between loops. 3. Keep the dmesg change locally. I am willing to accept any of these options, with #3 being done, #2 being v= ery simple, and #1 being a bit involved, but supporting a number of ideas I hav= e. Thoughts, suggestions, or ideas are welcomed! -Joe --=20 You are receiving this mail because: You are the assignee for the bug.=