Date: Mon, 27 Feb 2006 06:42:08 GMT From: Arthur Hartwig <Arthur.Hartwig@nokia.com> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/93887: cpu_spinwait calls missing Message-ID: <200602270642.k1R6g8VT025891@www.freebsd.org> Resent-Message-ID: <200602270650.k1R6o4Iq031143@freefall.freebsd.org>
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>Number: 93887 >Category: misc >Synopsis: cpu_spinwait calls missing >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon Feb 27 06:50:04 GMT 2006 >Closed-Date: >Last-Modified: >Originator: Arthur Hartwig >Release: 6.1-BETA1 >Organization: Nokia >Environment: oz-net-11# uname -a FreeBSD oz-net-11.nes.nokia.com 6.1-BETA1 FreeBSD 6.1-BETA1 #4: Tue Feb 21 14:01:31 EST 2006 root@oz-net-11.nes.nokia.com:/usr/src/sys/amd64/compile/oz-net-11 amd64 >Description: There are five busy wait loops in kern/subr_smp.c which would be more "multi-processor friendly" on i386 and amd64 architectures if they included a call to cpu_spinwait(). On these architectures the cpu_spinwait() executes a pause instruction which the Intel IA32 architecture manual says "improves the performance of spin wait loops." Loops which could include the call to cpu_spinwait() occur in stop_cpus(), stop_cpus_nmi(), restart_cpus(), and two in smp_rendezvous_action() >How-To-Repeat: >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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