lkml.org 
[lkml]   [2020]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH RFC v2 00/17] KVM: x86/pmu: Add support to enable Guest PEBS via DS
    On Mon, Nov 09, 2020 at 10:12:37AM +0800, Like Xu wrote:
    > The Precise Event Based Sampling(PEBS) supported on Intel Ice Lake server
    > platforms can provide an architectural state of the instruction executed
    > after the instruction that caused the event. This patch set enables the
    > the PEBS via DS feature for KVM (also non) Linux guest on the Ice Lake.
    > The Linux guest can use PEBS feature like native:
    >
    > # perf record -e instructions:ppp ./br_instr a
    > # perf record -c 100000 -e instructions:pp ./br_instr a
    >
    > If the counter_freezing is not enabled on the host, the guest PEBS will
    > be disabled on purpose when host is using PEBS facility. By default,
    > KVM disables the co-existence of guest PEBS and host PEBS.

    Uuhh, what?!? counter_freezing should never be enabled, its broken. Let
    me go delete all that code.

    \
     
     \ /
      Last update: 2020-11-10 16:14    [W:4.232 / U:0.028 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site