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Wysocki" Date: Thu, 22 Sep 2022 17:53:17 +0200 Message-ID: Subject: Re: [PATCH] ACPI: processor_idle: Skip dummy wait for processors based on the Zen microarchitecture To: Borislav Petkov Cc: "Rafael J. Wysocki" , Peter Zijlstra , K Prateek Nayak , Linux Kernel Mailing List , Len Brown , ACPI Devel Maling List , Linux PM , Dave Hansen , Thomas Gleixner , andi@lisas.de, Pu Wen , Mario Limonciello , "Zhang, Rui" , "Guilherme G. Piccoli" , Daniel Lezcano , ananth.narayan@amd.com, gautham.shenoy@amd.com, Calvin Ong , Stable , regressions@lists.linux.dev Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 22, 2022 at 5:36 PM Borislav Petkov wrote: > > On Thu, Sep 22, 2022 at 05:21:21PM +0200, Rafael J. Wysocki wrote: > > Well, it can be forced to use ACPI idle instead. > > Yeah, I did that earlier. The dummy IO read in question costs ~3K on > average on my Coffeelake box here. Well, that's the cost of forcing something non-default.