linux-kernel - Re: [PATCH 3/3][RFC/RFT] PM / sleep: Do not delay the synchronization of MTRR during resume

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Message-ID: <20180206141614.GA912@yu-chen.sh.intel.com>
Date:   Tue, 6 Feb 2018 22:16:14 +0800
From:   Yu Chen <yu.c.chen@...el.com>
To:     Lukas Wunner <lukas@...ner.de>
Cc:     x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Len Brown <len.brown@...el.com>, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Rui Zhang <rui.zhang@...el.com>
Subject: Re: [PATCH 3/3][RFC/RFT] PM / sleep: Do not delay the
 synchronization of MTRR during resume

On Tue, Feb 06, 2018 at 03:04:17PM +0100, Lukas Wunner wrote:
> On Thu, Dec 14, 2017 at 12:02:42AM +0800, Yu Chen wrote:
> > On Wed, Dec 13, 2017 at 01:31:50AM +0100, Rafael J. Wysocki wrote:
> > > On Tuesday, October 31, 2017 10:58:50 AM CET Yu Chen wrote:
> [snip]
> > > > In one word, with the patch applied, the cpu online time during resume
> > > > has decreased by about 6 seconds on a bogus MTRR platform, and decreased
> > > > by about 600ms on a 88 cpus Xeon platform after resumed.
> > > > 
> > > > Cc: Len Brown <len.brown@...el.com>
> > > > Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> > > > Cc: Rui Zhang <rui.zhang@...el.com>
> > > > Signed-off-by: Chen Yu <yu.c.chen@...el.com>
> > > 
> > > It will be better to combine this with patch [2/3] IMO, because that makes
> > > it clear why the changes in that patch are needed.
> > > 
> > > Also you can define the new flag in mtrr/main.c, set it in
> > > arch_enable_nonboot_cpus_begin() and clear it in
> > > arch_enable_nonboot_cpus_end().  It is better to put it into the
> > > arch-specific code as the flag itself is arch-specific.
> > > 
> > > Then, of course, you don't need patch [1/3] and all can be done in one
> > >  patch.
> > 
> > Ok, will rewrite the patch, thanks! 
> 
> Just for the record, this series cuts down resume time from system sleep
> by 4-5 seconds on my MacBookPro9,1.  Great work, looking forward to this
> being respun and merged.
> 
> Tested-by: Lukas Wunner <lukas@...ner.de>
>
Thanks Lukas,
I've sent the latest patch at:
https://patchwork.kernel.org/patch/10150077/
> Thanks,
> 
> Lukas