From owner-svn-src-all@freebsd.org Fri Jun 14 20:04:29 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6E16215B0264; Fri, 14 Jun 2019 20:04:29 +0000 (UTC) (envelope-from mav@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 04AE4770E5; Fri, 14 Jun 2019 20:04:29 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id D04231C99D; Fri, 14 Jun 2019 20:04:28 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x5EK4S3F070486; Fri, 14 Jun 2019 20:04:28 GMT (envelope-from mav@FreeBSD.org) Received: (from mav@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x5EK4SeW070485; Fri, 14 Jun 2019 20:04:28 GMT (envelope-from mav@FreeBSD.org) Message-Id: <201906142004.x5EK4SeW070485@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mav set sender to mav@FreeBSD.org using -f From: Alexander Motin Date: Fri, 14 Jun 2019 20:04:28 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r349040 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-SVN-Group: head X-SVN-Commit-Author: mav X-SVN-Commit-Paths: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-SVN-Commit-Revision: 349040 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 04AE4770E5 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.95)[-0.951,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 14 Jun 2019 20:04:29 -0000 Author: mav Date: Fri Jun 14 20:04:28 2019 New Revision: 349040 URL: https://svnweb.freebsd.org/changeset/base/349040 Log: Minimize aggsum_compare(&arc_size, arc_c) calls. For busy ARC situation when arc_size close to arc_c is desired. But then it is quite likely that aggsum_compare(&arc_size, arc_c) will need to flush per-CPU buckets to find exact comparison result. Doing that often in a hot path penalizes whole idea of aggsum usage there, since it replaces few simple atomic additions with dozens of lock acquisitions. Replacing aggsum_compare() with aggsum_upper_bound() in code increasing arc_p when ARC is growing (arc_size < arc_c) according to PMC profiles allows to save ~5% of CPU time in aggsum code during sequential write to 12 ZVOLs with 16KB block size on large dual-socket system. I suppose there some minor arc_p behavior change due to lower precision of the new code, but I don't think it is a big deal, since it should affect only very small window in time (aggsum buckets are flushed every second) and in ARC size (buckets are limited to 10 average ARC blocks per CPU). MFC after: 2 weeks Sponsored by: iXsystems, Inc. Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 14 19:57:32 2019 (r349039) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 14 20:04:28 2019 (r349040) @@ -5269,7 +5269,7 @@ arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, v * If we are growing the cache, and we are adding anonymous * data, and we have outgrown arc_p, update arc_p */ - if (aggsum_compare(&arc_size, arc_c) < 0 && + if (aggsum_upper_bound(&arc_size) < arc_c && hdr->b_l1hdr.b_state == arc_anon && (refcount_count(&arc_anon->arcs_size) + refcount_count(&arc_mru->arcs_size) > arc_p))