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Peter Zijlstra (Intel) authored
The Goldmont plus and Tremont have LBR format V7. The V7 has LBR_INFO, which is the same as LBR format V5. But V7 doesn't support TSX. Without the patch, the associated misprediction and cycles information in the LBR_INFO may be lost on a Goldmont plus platform. For Tremont, the patch only impacts the non-PEBS events. Because of the adaptive PEBS, the LBR_INFO is always processed for a PEBS event. Currently, two different ways are used to check the LBR capabilities, which make the codes complex and confusing. For the LBR format V4 and earlier, the global static lbr_desc array is used to store the flags for the LBR capabilities in each LBR format. For LBR format V5 and V6, the current code checks the version number for the LBR capabilities. There are common LBR capabilities among LBR format versions. Several flags for the LBR capabilities are introduced into the struct x86_pmu. The flags, which can be shared among LBR formats, are used to check the LBR capabilities. Add intel_pmu_lbr_init() to set the flags accordingly at boot time. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lkml.kernel.org/r/1641315077-96661-1-git-send-email-peterz@infradead.org
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