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:	Sat, 22 Mar 2014 09:18:37 +0530
From:	Viresh Kumar <>
To:	Catalin Marinas <>
Cc:	"Srivatsa S. Bhat" <>,
	"Rafael J. Wysocki" <>,
	Lists linaro-kernel <>,
	"" <>,
	"" <>,
	Linux Kernel Mailing List <>,
	"" <>
Subject: Re: [PATCH V4 1/3] cpufreq: Make sure frequency transitions are serialized

On 21 March 2014 23:37, Catalin Marinas <> wrote:
> smp_mb() is all about relative ordering. So if you want memory accesses
> in post_transition() to be visible to other observers before
> transition_ongoing = false, you also need to make sure that the readers
> of transition_ongoing have a barrier before subsequent memory accesses.

I don't think this is a requirement in our case. We are just trying to serialize
frequency transitions here and just want to make sure that second one
start after first one is over. And so this query.

> OK, I start to get it. Is there a risk of missing a wake_up event? E.g.
> one thread waking up earlier, noticing that transition is in progress
> and waiting indefinitely?

I don't think so. The only requirement is that second thread wakes up
after this variable is set to false.
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