Date: Sat, 12 Jan 2008 08:21:01 GMT From: KOIE Hidetaka <koie@suri.co.jp> To: freebsd-gnats-submit@FreeBSD.org Subject: ports/119589: default parameter of powerd is unsuitable for multi core system. Message-ID: <200801120821.m0C8L1Ut093325@www.freebsd.org> Resent-Message-ID: <200801120830.m0C8U1wO070465@freefall.freebsd.org>
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>Number: 119589 >Category: ports >Synopsis: default parameter of powerd is unsuitable for multi core system. >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-ports-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Sat Jan 12 08:30:01 UTC 2008 >Closed-Date: >Last-Modified: >Originator: KOIE Hidetaka >Release: FreeBSD 8.0-CURRENT amd64 >Organization: surigiken >Environment: FreeBSD guriandgura 8.0-CURRENT FreeBSD 8.0-CURRENT #0: Sat Jan 5 16:35: 45 JST 2008 koie@guriandgura:/usr/obj/usr/src/sys/GURIANDGURA amd64 >Description: On multi core system, powerd will not increase performance. For example, if NCPU=4 and one process consumes a CPU, system-wide CPU idle is >= 75%. Because the threashold is 65% by default, powerd never increase performace. >How-To-Repeat: >Fix: Change default setting: DEFAULT_ACTIVE_PERCENT = (100 * (NCPU - 1) + 65) / NCPU, DEFAULT_IDLE_PERCENT = (100 * (NCPU - 1) + 90) / NCPU. if NCPU=4, DEFAULT_ACTIVE_PERCENT = 91, DEFAULT_IDLE_PERCENT = 97. Or, powerd polls per-core CPU statistics kern.cp_times and increases performance when any CPU is busy. Or, kernel and powerd support per-core power management. >Release-Note: >Audit-Trail: >Unformatted:
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