linux-kernel - Re: [PATCH] Parallelize mtrr init between cpus

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, 07 Aug 2012 20:53:06 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	zhenzhong.duan@...cle.com
CC:	tglx@...utronix.de, mingo@...hat.com, x86@...nel.org,
	linux-kernel@...r.kernel.org,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Feng Jin <joe.jin@...cle.com>
Subject: Re: [PATCH] Parallelize mtrr init between cpus

On 08/07/2012 07:08 PM, zhenzhong.duan wrote:
>
>
>   2012-08-08 00:32, H. Peter Anvin wrote:
>> On 08/07/2012 12:29 AM, zhenzhong.duan wrote:
>>> Current code serialize mtrr init with set_atomicity_lock.
>>> Mtrr init is quite slow when we bootup on a hvm with large mem, vcpus
>>> and pci passthroughed devices(eg. 24 vcpus + 90G mem).
>>> It took about ~30 mins to bootup, after patch, it took ~2 min.
>> When you're saying "HVM" do you mean "Xen HVM"?  How does it behave on
>> native hardware?
>>
>>     -hpa
> Yes, I mean Xen HVM. Bootup at same speed as before on baremetal.

Then I would like to know why Xen HVM takes so infernally long.  It 
isn't a good idea to make gratuitous changes in the main kernel to work 
around defects in Xen.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/