Date: Mon, 27 Mar 2017 09:45:28 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r316017 - head/sys/x86/x86 Message-ID: <201703270945.v2R9jSov001041@repo.freebsd.org>
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Author: avg Date: Mon Mar 27 09:45:27 2017 New Revision: 316017 URL: https://svnweb.freebsd.org/changeset/base/316017 Log: add SMT detection for newer AMD processors The change seems to be more in the nomenclature than in the way the topology is advertised by the hardware. Tested by: truckman (earlier version of the change) MFC after: 2 weeks Modified: head/sys/x86/x86/mp_x86.c Modified: head/sys/x86/x86/mp_x86.c ============================================================================== --- head/sys/x86/x86/mp_x86.c Mon Mar 27 08:29:46 2017 (r316016) +++ head/sys/x86/x86/mp_x86.c Mon Mar 27 09:45:27 2017 (r316017) @@ -255,6 +255,22 @@ topo_probe_amd(void) pkg_id_shift = mask_width((cpu_procinfo2 & AMDID_CMP_CORES) + 1); + /* + * Families prior to 16h define the following value as + * cores per compute unit and we don't really care about the AMD + * compute units at the moment. Perhaps we should treat them as + * cores and cores within the compute units as hardware threads, + * but that's up for debate. + * Later families define the value as threads per compute unit, + * so we are following AMD's nomenclature here. + */ + if ((amd_feature2 & AMDID2_TOPOLOGY) != 0 && + CPUID_TO_FAMILY(cpu_id) >= 0x16) { + cpuid_count(0x8000001e, 0, p); + share_count = ((p[1] >> 8) & 0xff) + 1; + core_id_shift = mask_width(share_count); + } + if ((amd_feature2 & AMDID2_TOPOLOGY) != 0) { for (i = 0; ; i++) { cpuid_count(0x8000001d, i, p);
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