linux-kernel - Re: [PATCH v3] Optimize C3 entry on Centaur CPUs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20181231172654.GB14092@amd>
Date:   Mon, 31 Dec 2018 18:26:54 +0100
From:   Pavel Machek <pavel@....cz>
To:     David Wang <davidwang@...oxin.com>
Cc:     rjw@...ysocki.net, mingo@...hat.com, len.brown@...el.com,
        tglx@...utronix.de, hpa@...or.com, x86@...nel.org,
        linux-pm@...nel.org, linux-kernel@...r.kernel.org,
        brucechang@...-alliance.com, cooperyan@...oxin.com,
        qiyuanwang@...oxin.com, timguo@...oxin.com
Subject: Re: [PATCH v3] Optimize C3 entry on Centaur CPUs

On Thu 2018-12-27 16:41:50, David Wang wrote:
> For new Centaur CPUs the ucode will take care of the preservation of cache coherence
> between CPU cores in C-states regardless of how deep the C-states are. So, it is not
> necessary to flush the caches in software befor entering C3. And this useless operation
> will cause performance drop for the cores which share some caches with the idling core.  
> 
> Signed-off-by: David Wang <davidwang@...oxin.com>
> Reviewed-by: Thomas Gleixner <tglx@...utronix.de>

Acked-by: Pavel Machek <pavel@....cz>

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)