public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "Chang S. Bae" <chang.seok.bae@intel.com>
To: <linux-kernel@vger.kernel.org>
Cc: <x86@kernel.org>, <tglx@linutronix.de>, <mingo@redhat.com>,
	<bp@alien8.de>, <dave.hansen@linux.intel.com>,
	<tony.luck@intel.com>, <ashok.raj@intel.com>,
	Yan Hua Wu <yanhua1.wu@intel.com>
Subject: Re: [PATCH 1/1] arch/x86/microcode/intel: Remove unnecessary cache writeback and invalidation
Date: Tue, 10 Sep 2024 11:35:35 -0700	[thread overview]
Message-ID: <dc3c2ba3-73db-4609-bc34-3181c44d0dd0@intel.com> (raw)
In-Reply-To: <20240701212012.21499-2-chang.seok.bae@intel.com>

On 7/1/2024 2:20 PM, Chang S. Bae wrote:
> 
> Additionally, the side effects of doing this have been overlooked. It
> extends the CPU rendezvous time for late loading. The cache flush takes
> about 1x to 3.5x more time than needed for updating the microcode.

To provide more context, the latency impact was found to be more adverse 
when late loading was staged using the new loading feature [1]. Its 
enabling patch set will be posted once the specification is updated, 
likely after the upcoming merge window. I will include this fix (v2) as 
part of the series.

Thanks,
Chang

[1]: https://cdrdv2.intel.com/v1/dl/getContent/782715


      parent reply	other threads:[~2024-09-10 18:36 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-01 21:20 [PATCH 0/1] x86/microcode: Revert cache flush on Intel microcode loading Chang S. Bae
2024-07-01 21:20 ` [PATCH 1/1] arch/x86/microcode/intel: Remove unnecessary cache writeback and invalidation Chang S. Bae
2024-07-01 22:56   ` Dave Hansen
2024-07-03 20:50     ` Ashok Raj
2024-07-03 20:55       ` Dave Hansen
2024-07-03 21:03         ` Ashok Raj
2024-07-03 21:11           ` Dave Hansen
2024-07-03 21:33             ` Ashok Raj
2024-07-04  0:05               ` Chang S. Bae
2024-07-02 23:24   ` Chang S. Bae
2024-09-10 18:35   ` Chang S. Bae [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=dc3c2ba3-73db-4609-bc34-3181c44d0dd0@intel.com \
    --to=chang.seok.bae@intel.com \
    --cc=ashok.raj@intel.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=tony.luck@intel.com \
    --cc=x86@kernel.org \
    --cc=yanhua1.wu@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox