From nobody Wed Mar 6 18:12:20 2024 X-Original-To: fs@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 4TqgWS6sTnz5D338 for ; Wed, 6 Mar 2024 18:12:20 +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 4TqgWS5r5Jz4vsl for ; Wed, 6 Mar 2024 18:12:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1709748740; a=rsa-sha256; cv=none; b=CUVdl6JFaQatxxLPvmrrCTrZniSmCxZQ9pOCpVfiXUlIeOIvlXLkZ8PnKLOKiawV4Oukqb z3dzEXZjCMPSTc05Z4u50L1W/uPxJnk0xitMw87WO7AqOXq8UszC8U7YXBPgA8e8upkWMa A6iywCZaSk8JpG6rcQCNgKGZItQ9MuHqJM0AuxMRybQbBETQU4cvh8+afLQjlLJCfDtJe1 aartJB6UxSs/6bhTMKqCnOcYP+BYwr2+CdvLQMwdmR+qiJuMa/AVhnQj4azWD25EjhrbTA 4ZBpN/yxTgajsmKI/co4MyMhlaiQ/FHJRuAT5koRekKFNQI8lzJ1Bvo/kOJEfA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1709748740; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=nKnxB5yb4NAM0hbKdOm5r4sPHQEzBVARjB9oNbAw+X4=; b=fHQTIBENjwHao6z1HSAP10cUS/x+zafooM+ScLetV67Jt7qhOIzN+J3IGguNuJJ7uGQYFl sahGrkOt5MsQSEce+WizE9/6hwULS0csaDou+0r5UAzh8USBsSE9J01qlote7dbN/5RPt9 l5m4ZoAklQ2gZ7penQ/JKcdUbbcjTxrdT2f+Jnc6PzznDZmtFyg86VQwxUN4lnddeawm9Y ZAkTz/e2WdAcTH6jKqbA5xIltt2nHXFI6ky2vGZVW6GoB9+fdXWvkuc8/IqDtpxx2GLGiU UL7aaFaBYVL5YXYPGBJVLX3g6qEyTZciy8moDCDLfa0c1NvbOAjuMPMDS0izrA== 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 4TqgWS5Rg6z11BL for ; Wed, 6 Mar 2024 18:12:20 +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 426ICKF6058648 for ; Wed, 6 Mar 2024 18:12:20 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 426ICKZ4058647 for fs@FreeBSD.org; Wed, 6 Mar 2024 18:12:20 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: fs@FreeBSD.org Subject: [Bug 275594] High CPU usage by arc_prune; analysis and fix Date: Wed, 06 Mar 2024 18:12:20 +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: 14.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: vsasjason@gmail.com X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: fs@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: Filesystems List-Archive: https://lists.freebsd.org/archives/freebsd-fs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-fs@freebsd.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D275594 --- Comment #73 from Anton Saietskii --- (In reply to Mark Millard from comment #72) TBH, I didn't really get what do you mean by "kind" of hang, but perhaps following will be helpful: (Vanilla releng/13.3 currently.) Machine is running a few daemons with very stable memory footprint (built-in ones, like sshd, ntpd + couple of 3rd party, like net/wifibox, net-p2p/transmission daemon). Nothing related to memory has been tuned, and there's always ~2-3G of free RAM and zero swap usage. Then I start `poudriere bulk`, and as soon as some big distfile (e.g. firef= ox, libreoffice) begins extraction to tmpfs, arc_prune+vnlru start recklessly e= at CPU^W^W^W do their job trying to evict some ARC for me. System becomes slow= and stuttering followed by a full unresponsiveness =E2=80=94 network stops, dis= k activity stops, no reaction on physical console. After several minutes (I guess when distfile finishes extraction), everythi= ng returns to normal like nothing happened with no any log messages. Then poudriere build continues with eventual arc_prune+vnlru running as tmpfs be= ing filled with object files produced by compiler. No a single byte of swap usa= ge observed during this. So, it's like what you described, but for me issue hits faster and harder. Looks like CPU just have no time to execute anything beyond those 2 and possibly some other kernel threads. --=20 You are receiving this mail because: You are the assignee for the bug.=