linux-kernel - Re: [PATCH V2 5/5] perf/x86: Add Intel Nehalem-EX uncore support

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:	Thu, 5 Jul 2012 16:51:24 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	"Yan, Zheng" <zheng.z.yan@...el.com>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>, eranian@...gle.com,
	mingo@...e.hu, andi@...stfloor.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V2 5/5] perf/x86: Add Intel Nehalem-EX uncore support

On Thu, Jul 05, 2012 at 02:32:17PM +0800, Yan, Zheng wrote:
> The uncore subsystem in Nehalem-EX consists of 7 components
> (U-Box, C-Box, B-Box, S-Box, R-Box, M-Box and W-Box). This
> patch is large because the way to program these boxes is
> diverse.

Thanks for doing the driver. Lots of work.

May be worth adding a CONFIG for the uncore code now?
Maybe even a module, so that not every distro kernel has it always
in memory. I don't think perf has support for tracking
module counts, but I guess it would be ok to have the module be not
unloadable once loaded by setting the count to -1.

Also did you do some random testing by putting randomized values into
all the exported registers and see if anything is crashable for 
unpriv. userspace?

> +		 * events are functional identical, but use different
> +		 * extra registers. If we failed to take an extra
> +		 * register, try the alternative.
> +		 */
> +		if (idx % 2)
> +			idx--;
> +		else
> +			idx++;
> +		if (idx != reg1->idx % 6) {
> +			if (idx == 2)
> +				config1 >>= 8;
> +			else if (idx == 3)
> +				config1 <<= 8;
> +			goto again;

Does this limit the retries?

> @@ -1767,6 +2821,9 @@ static int __init uncore_cpu_init(void)
>  			snbep_uncore_cbox.num_boxes = max_cores;
>  		msr_uncores = snbep_msr_uncores;
>  		break;
> +	case 46:
> +		msr_uncores = nhmex_msr_uncores;
> +		break;

Ok need Westmere-EX too. I think that is quite similar.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
--
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/