linux-kernel - Re: [PATCH 4/6] x86/cpufreq: use cpumask

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Tue, 9 Jun 2009 08:46:44 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Rusty Russell <rusty@...tcorp.com.au>
cc:	Yinghai Lu <yinghai@...nel.org>, Avi Kivity <avi@...hat.com>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Dave Jones <davej@...hat.com>, cpufreq@...r.kernel.org
Subject: Re: [PATCH 4/6] x86/cpufreq: use cpumask_copy instead of =

On Tue, 9 Jun 2009, Rusty Russell wrote:
>  
>  	for_each_online_cpu(i) {
> -		if (check_supported_cpu(i))
> +		if (work_on_cpu(i, check_supported_cpu, NULL) == 0)
>  			supported_cpus++;

Please STOP USING THAT HORRIBLE "work_on_cpu()" crap.

Is there any reason you do that? We've had to fix up the fallout from that 
kind of crazy crap several times.

Just use a regular IPI. Use "smp_call_function_[single|many]()" instead.

See for example commit 01599fca6758d2cd133e78f87426fc851c9ea725, where 
another "work_on_cpu()" thing was broken.

I don't understand why you guys keep on using that _known_ bad function. 
The whole point of "work_on_cpu()" is for big, slow, and rare things. Not 
as a random "let's make that CPU do this".

So stop it. 

			Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/