Date: Sat, 02 Jun 2007 21:15:13 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Kris Kennaway <kris@obsecurity.org> Cc: takawata@freeBSD.org, Dag-Erling Sm??rgrav <des@des.no>, current@freeBSD.org, Nate Lawson <nate@root.org> Subject: Re: HPET vs other timers Message-ID: <47223.1180818913@critter.freebsd.dk> In-Reply-To: Your message of "Sat, 02 Jun 2007 15:41:51 -0400." <20070602194151.GA1604@rot13.obsecurity.org>
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In message <20070602194151.GA1604@rot13.obsecurity.org>, Kris Kennaway writes: >> Anyone able to speculate why though? HPET only reads 32 bits from a >> memory mapped region. No locking or other requirements. ACPI_timer >> does multiple IO ops, which according to bde@ are much slower than >> memory reads. HPET needs to do metastability mitigation and is not "just a read from a memory mapped region". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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