Date: Fri, 24 Oct 2014 19:45:00 +0000 (GMT) From: Rui Paulo <rpaulo@me.com> To: Andriy Gapon <avg@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org, Rui Paulo <rpaulo@FreeBSD.org> Subject: Re: svn commit: r273598 - in head: include sys/dev/acpica Message-ID: <2f9b110c-2681-4e3d-b9e0-5ca0eb2763f9@me.com>
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On Oct 24, 2014, at 12:06 PM, Andriy Gapon <avg@FreeBSD.org> wrote:=0A=0AO= n 24/10/2014 21:39, Rui Paulo wrote:=0A> Author: rpaulo=0A> Date: Fri Oct = 24 18:39:15 2014=0A> New Revision: 273598=0A> URL: https://svnweb.freebsd.= org/changeset/base/273598=0A> =0A> Log:=0A> HPET: create /dev/hpetN as a w= ay to access HPET from userland.=0A> =0A> In some cases, TSC is broken and= special applications might benefit=0A> from memory mapping HPET and readi= ng the registers to count time.=0A> Most often the main HPET counter is 32= -bit only[1], so this only gives=0A> the application a 300 second window b= ased on the default HPET=0A> interval.=0A> Other applications, such as Int= el's DPDK, expect /dev/hpet to be=0A> present and use it to count time as = well.=0A=0ADoes this device attempt to play nice with eventtimer infrastru= cture that may=0Ause the same timer?=0A=C2=A0=0ANo. =C2=A0That's up to the= userland applications and that's why I implemented the read-only restrict= ion.=
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