lkml.org 
[lkml]   [2021]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 2/2] iommu/amd: Remove performance counter pre-initialization test
    From
    Date
    David,

    On 4/14/2021 10:33 PM, David Coe wrote:
    > Hi Suravee!
    >
    > I've re-run your revert+update patch on Ubuntu's latest kernel 5.11.0-14 partly to check my mailer's 'mangling' hadn't also reached the code!
    >
    > There are 3 sets of results in the attachment, all for the Ryzen 2400G. The as-distributed kernel already incorporates your IOMMU RFCv3 patch.
    >
    > A. As-distributed kernel (cold boot)
    >    >5 retries, so no IOMMU read/write capability, no amd_iommu events.
    >
    > B. As-distributed kernel (warm boot)
    >    <5 retries, amd_iommu running stats show large numbers as before.
    >
    > C. Revert+Update kernel
    >    amd_iommu events listed and also show large hit/miss numbers.
    >
    > In due course, I'll load the new (revert+update) kernel on the 4700G but won't overload your mail-box unless something unusual turns up.
    >
    > Best regards,
    >

    For the Ryzen 2400G, could you please try with:
    - 1 event at a time
    - Not more than 8 events (On your system, it has 2 banks x 4 counters/bank.
    I am trying to see if this issue might be related to the counters multiplexing).

    Thanks,
    Suravee

    \
     
     \ /
      Last update: 2021-04-15 11:29    [W:2.184 / U:0.032 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site