Date: Tue, 2 Oct 2007 01:30:18 +0000 (UTC) From: Jeff Roberson <jeff@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/kern sched_ule.c Message-ID: <200710020130.l921UIfM070521@repoman.freebsd.org>
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jeff 2007-10-02 01:30:18 UTC
FreeBSD src repository
Modified files:
sys/kern sched_ule.c
Log:
- Reassign the thread queue lock to newtd prior to switching. Assigning
after the switch leads to a race where the outgoing thread still owns
the local queue lock while another cpu may switch it in. This race
is only possible on machines where cpu_switch can take significantly
longer on different cpus which in practice means HTT machines with
unfair thread scheduling algorithms.
Found by: kris (of course)
Approved by: re
Revision Changes Path
1.212 +6 -4 src/sys/kern/sched_ule.c
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