From nobody Sat May 29 09:52:34 2021 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 783A9D786E6 for ; Sat, 29 May 2021 09:52:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FscKv2w3mz4Zvl for ; Sat, 29 May 2021 09:52:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4C83B27E57 for ; Sat, 29 May 2021 09:52:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 14T9qZiK041338 for ; Sat, 29 May 2021 09:52:35 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 14T9qZ7l041337 for net@FreeBSD.org; Sat, 29 May 2021 09:52:35 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 256217] [tcp] High system load because of interrupts with RACK Date: Sat, 29 May 2021 09:52:34 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 13.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: chris@cretaforce.gr X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@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 List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D256217 --- Comment #7 from Christos Chatzaras --- I was able to reproduce the issue with a "test" server && 10 VPS running Li= nux. On each VPS I run wrk (benchmarking tool): wrk -c 1000 -d 3600s http://url This creates 10000 concurrent connections to "test" server. Also in my nginx.conf I replace "keepalive_timeout 60;" with "keepalive_tim= eout 0;" so connections are not reused which helps to show more interrupts faste= r. Then I kill all "wrk" and after 1 minute: sockstat -sSPtcp | grep rack | wc -l 7421 At that moment "top" shows 20% interrupts and "netstat 1" show 1-10 packets= / sec which I believe is my ssh session, so no activity. Also at that moment = tcp "rack" states were FIN_WAIT_1 and CLOSING. After few minutes most "rack" connections close and "top" shows ~ 0.7% interrupts. At that moment I had 4 stuck connections in LAST_ACK state whic= h I drop using "tcpdrop -s LAST_ACK" and finally "top" shows ~ 0.0% interrupts. If it helps I can give root access to the "test" server. --=20 You are receiving this mail because: You are the assignee for the bug.=