Date: Tue, 02 Jun 2026 06:42:03 +0000 From: ShengYi Hung <aokblast@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 7b26353a59d6 - main - hwpstate_intel: Disable package control on hybrid CPU Message-ID: <6a1e7b3b.1a45a.91f6820@gitrepo.freebsd.org>
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The branch main has been updated by aokblast: URL: https://cgit.FreeBSD.org/src/commit/?id=7b26353a59d66dc1bc611fd042a49b9e3bd13699 commit 7b26353a59d66dc1bc611fd042a49b9e3bd13699 Author: ShengYi Hung <aokblast@FreeBSD.org> AuthorDate: 2026-06-01 09:46:37 +0000 Commit: ShengYi Hung <aokblast@FreeBSD.org> CommitDate: 2026-06-02 06:41:41 +0000 hwpstate_intel: Disable package control on hybrid CPU In package control mode, the performance of all cores depends on the most recent value written to the request field. If the last write comes from an E-core, all cores are forced to align with the E-core performance level, resulting in significant performance degradation. Therefore, package control is disabled on hybrid-core systems. Reviewed by: olce MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Sponsored by: Framework Computer Inc Differential Revision: https://reviews.freebsd.org/D57377 --- sys/x86/cpufreq/hwpstate_intel.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/sys/x86/cpufreq/hwpstate_intel.c b/sys/x86/cpufreq/hwpstate_intel.c index 3d2cc0a5966b..db8600d7b89a 100644 --- a/sys/x86/cpufreq/hwpstate_intel.c +++ b/sys/x86/cpufreq/hwpstate_intel.c @@ -321,9 +321,19 @@ out: return (ret); } +static void +intel_hwpstate_hybrid_cb(void *ctx) +{ + uint32_t *small_cores = ctx; + + atomic_add_32(small_cores, PCPU_GET(small_core)); +} + void intel_hwpstate_identify(driver_t *driver, device_t parent) { + uint32_t small_cores = 0; + if (device_find_child(parent, "hwpstate_intel", DEVICE_UNIT_ANY) != NULL) return; @@ -343,6 +353,17 @@ intel_hwpstate_identify(driver_t *driver, device_t parent) if ((cpu_power_eax & CPUTPM1_HWP) == 0) return; + /* + * On hybrid-core systems, package-level control cannot be used. + * It may cause all cores to run at the E-core frequency because + * the resulting package frequency depends on the last core that + * sets the frequency. + */ + smp_rendezvous_cpus(all_cpus, smp_no_rendezvous_barrier, + intel_hwpstate_hybrid_cb, smp_no_rendezvous_barrier, &small_cores); + if (small_cores > 0 && small_cores < mp_ncores) + hwpstate_pkg_ctrl_enable = false; + if (BUS_ADD_CHILD(parent, 10, "hwpstate_intel", device_get_unit(parent)) == NULL) device_printf(parent, "hwpstate_intel: add child failed\n");home | help
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