Messages in this thread | | | From | "Chang S. Bae" <> | Subject | [PATCH v5 0/2] x86/fpu: Make AMX state ready for CPU idle | Date | Wed, 8 Jun 2022 09:47:46 -0700 |
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Here is the fifth version of this series.
I've addressed Dave's comment [2] assuming that the change makes sense to folks: * Check the AMX_TILE feature bit instead of XGETBV1. * Massage the changelog accordingly.
While many people had their eyeballs on this, Rafael's ACK was given so far. Hopefully this can attracts more acknowledgment or endorsement if it looks fine.
=== Cover Letter ===
AMX state is a large state (at least 8KB or more). Entering CPU idle with this non-initialized large state may result in shallow states while a deeper low-power state is available.
We can confirm this behavior is implementation-specific. Section 3.3 in [3] will be updated to clarify this.
This patch set ensures the AMX state is initialized before entering the CPU idle state.
The patch set is based on 5.19-rc1. It is also available here: git://github.com/intel/amx-linux.git tilerelease
[1]: V4 https://lore.kernel.org/lkml/20220517222430.24524-1-chang.seok.bae@intel.com/ [2]: https://lore.kernel.org/lkml/25a2a82f-b5e5-0fce-86c8-03d7da5fcdd1@intel.com/ [3]: Intel Architecture Instruction Set Extension Programming Reference May 2021, https://software.intel.com/content/dam/develop/external/us/en/documents-tps/architecture-instruction-set-extensions-programming-reference.pdf
Chang S. Bae (2): x86/fpu: Add a helper to prepare AMX state for low-power CPU idle intel_idle: Add a new flag to initialize the AMX state
arch/x86/include/asm/fpu/api.h | 2 ++ arch/x86/include/asm/special_insns.h | 9 +++++++++ arch/x86/kernel/fpu/core.c | 14 ++++++++++++++ drivers/idle/intel_idle.c | 18 ++++++++++++++++-- 4 files changed, 41 insertions(+), 2 deletions(-)
base-commit: f2906aa863381afb0015a9eb7fefad885d4e5a56 -- 2.17.1
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