Date: Mon, 26 Jan 2004 10:26:56 -0500 From: John Baldwin <jhb@FreeBSD.org> To: Jeff Roberson <jeff@FreeBSD.org>, src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/i386 local_apic.c Message-ID: <200401261026.56106.jhb@FreeBSD.org> In-Reply-To: <200401250503.i0P53EoN026914@repoman.freebsd.org> References: <200401250503.i0P53EoN026914@repoman.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sunday 25 January 2004 12:03 am, Jeff Roberson wrote:
> jeff 2004/01/24 21:03:14 PST
>
> FreeBSD src repository
>
> Modified files:
> sys/i386/i386 local_apic.c
> Log:
> - Don't define DETECT_DEADLOCK. I don't know that this code has
> detected a deadlock in several years. Furthermore, the IPI code is
> currently protected by a seperate spinlock. This only served to make IPIs
> twice as expensive as they had to be which severely slowed down the IPI
> heavy ULE scheduler.
What spinlock?
> grep mtx local_apic.c | wc -l
0
Some users of the ipi API use a spinlock themselves, but not all, and there
certainly isn't a global ipi spin lock. According to witness, only sparc64
has an ipi spin lock. It might still be a good idea to turn this off or
perhaps at least half of it. We will lose ipi's on non-XAPIC systems if you
don't wait for the delivery status to clear before sending an IPI. Have you
tested this on Pentium II's or earlier?
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200401261026.56106.jhb>