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Yes. > > On 7/7/26 2:50 PM, Babu Moger wrote: >> Customers have identified an issue while using the QoS resource control >> feature. If memory bandwidth associated with a CLOSID is aggressively >> throttled, and a task with that CLOSID moves into kernel mode, the kernel >> operations are also aggressively throttled. This can stall forward progress >> and eventually degrade overall system performance. >> >> AMD hardware supports a feature Privilege Level Zero Association (PLZA), >> which allows the CPU's CLOSID association to be changed during the >> transition from user mode to kernel mode. This allows the kernel to run >> using a different CLOSID than user space, which can improve system >> performance in certain scenarios. > > How should user interpret "in certain scenarios"? Could the scenarios > be highlighted ... or maybe just drop this since it is already preceded > with "can improve system performance". Will remove "in certain scenarios". > > This description implies that PLZA is a feature that is only related > to memory bandwidth allocation where it can be beneficial. As I understand > the feature impacts all allocation features concurrently, including cache > allocation where it should be used with care? Yes. Let me add text about CAT. > > If the goal is to describe all the feature capabilities then it may be > worth a mention of the impact/usage related to monitoring? Yes. Need to mention monitoring also. > >> >> The feature is detected via CPUID_Fn80000020_EBX_x00 [Bit 9]: >> Privilege Level Zero Association (PLZA). >> >> The PLZA feature details are documented in [1] available from [2]. >> >> [1] AMD64 Zen6 Platform Quality of Service (PQOS) Extensions: >> Publication # 69193 Revision: 1.00, Issue Date: March 2026 >> >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 # [2] >> Signed-off-by: Babu Moger > > Please follow "Ordering of commit tags" found in Documentation/process/maintainer-tip.rst. > Yes. Link should be the last one. Thanks Babu