Date: Fri, 8 Dec 2017 00:23:25 +0200 From: Andriy Gapon <avg@FreeBSD.org> To: Alexey Dokuchaev <danfe@freebsd.org>, Jung-uk Kim <jkim@freebsd.org> Cc: cem@freebsd.org, svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers <src-committers@freebsd.org> Subject: Re: svn commit: r326383 - head/sys/x86/cpufreq Message-ID: <d91cbdff-d5ce-35a3-19e3-c16b9237d10e@FreeBSD.org> In-Reply-To: <20171207100345.GA59559@FreeBSD.org> References: <201711300140.vAU1e7dC001292@repo.freebsd.org> <CAG6CVpVyooSG3rPG1GvqRZHT9Lyh48JBQb_tFf2-CzWmfW8JyQ@mail.gmail.com> <e412e02d-8b52-221f-1f3c-8c300b1b3067@FreeBSD.org> <CAG6CVpVtm%2BUUw1zxxGXEjKT8MqL8ZjqSaQh4=_0NJbFmcbQxVw@mail.gmail.com> <af56c6b4-d964-4a19-5647-3778eb0cc508@FreeBSD.org> <20171207100345.GA59559@FreeBSD.org>
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On 07/12/2017 12:03, Alexey Dokuchaev wrote: > On Thu, Nov 30, 2017 at 03:08:49PM -0500, Jung-uk Kim wrote: >> ... >> Probably. However, I am just trying to fix my FX-8350 and A10-6800 and >> I don't have Zen processors to verify the MSRs are actually working on >> those CPUs. > > Ah, that's so lovely, thanks Jung-uk; I feel that our support for AMD > fam. 15h CPUs is lacking. E.g. only four P-states are reported for my > A8-5550M, while it supports boosted P-states per BKDG, and reading MSRs > directly via `sysutils/amdmsrtweaker' reports eight of them (P0 .. P7), > with three turbo P-states P0 P1 P2. > > Since you have A10-6800 you might try to reproduce what I see here with > A8-5550M. I think that the boosted states are supposed to be hidden from the OS. It may be possible to query them though hardware specific registers, but they can not be set by software directly anyway. My impression is that the proper way to observe the boost states is via APERF / MPERF MSRs. They are useful for other things, e.g. C0 residency, too. P.S. i7z-like utility for AMD would be nice to have. -- Andriy Gapon
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