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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 28 Jul 2014 16:38:40 -0400
From:	Len Brown <>
To:	Jason Baron <>
Cc:	Linux PM list <>,
	"" <>
Subject: Re: [PATCH] intel_idle: use static_key to optimize idle enter/exit paths

On Fri, Jul 11, 2014 at 1:54 PM, Jason Baron <> wrote:
> If 'arat' is set in the cpuflags, we can avoid the checks for entering/exiting
> the tick broadcast code entirely. It would seem that this is a hot enough code
> path to make this worthwhile. I ran a few hackbench runs, and consistenly see
> reduced branches and cycles.

Hi Jason,

Your logic looks right -- though I've never used this
static_key_slow_inc() stuff.
I'm impressed that something in user-space could detect this change.

Can you share how to run the workload where you detected a difference,
and describe the hardware you measured?

-Len Brown, Intel Open Source Technology Center
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists